Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-30 (of 60 Records) |
Query Trace: Omer SB[original query] |
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Changing social contact patterns among US workers during the COVID-19 pandemic: April 2020 to December 2021
Kiti MC , Aguolu OG , Zelaya A , Chen HY , Ahmed N , Batross J , Liu CY , Nelson KN , Jenness SM , Melegaro A , Ahmed F , Malik F , Omer SB , Lopman BA . Epidemics 2023 45 100727 Non-pharmaceutical interventions minimize social contacts, hence the spread of respiratory pathogens such as influenza and SARS-CoV-2. Globally, there is a paucity of social contact data from the workforce. In this study, we quantified two-day contact patterns among USA employees. Contacts were defined as face-to-face conversations, involving physical touch or proximity to another individual and were collected using electronic self-kept diaries. Data were collected over 4 rounds from 2020 to 2021 during the COVID-19 pandemic. Mean (standard deviation) contacts reported by 1456 participants were 2.5 (2.5), 8.2 (7.1), 9.2 (7.1) and 10.1 (9.5) across round 1 (April-June 2020), 2 (November 2020-January 2021), 3 (June-August 2021), and 4 (November-December 2021), respectively. Between round 1 and 2, we report a 3-fold increase in the mean number of contacts reported per participant with no major increases from round 2-4. We then modeled SARS-CoV-2 transmission at home, work, and community settings. The model revealed reduced relative transmission in all settings in round 1. Subsequently, transmission increased at home and in the community but remained exceptionally low in work settings. To accurately parameterize models of infection transmission and control, we need empirical social contact data that capture human mixing behavior across time. |
Social contact patterns among employees in 3 U.S. companies during early phases of the COVID-19 pandemic, April to June 2020 (preprint)
Kiti MC , Aguolu OG , Liu CY , Mesa AR , Regina R , Willebrand K , Couzens C , Bartelsmeyer T , Nelson KN , Jenness S , Riley S , Melegaro A , Ahmed F , Malik F , Lopman BA , Omer SB . medRxiv 2020 2020.10.14.20212423 Importance Devising control strategies against diseases such as COVID-19 require understanding of contextual social mixing and contact patterns. There has been no standardized multi-site social contact study conducted in workplace settings in the United States that can be used to broadly inform pandemic preparedness policy in these settings.Objective The study aimed to characterize the patterns of social contacts and mixing across workplace environments, including on-site or when teleworking.Design This was a cross-sectional non-probability survey that used standardized social contact diaries to collect data. Employees were requested to record their physical and non-physical contacts in a diary over two consecutive days, documented at the end of each day. Employees from each company were enrolled through email and electronic diaries sent as individual links. Data were collected from April to June 2020.Setting Two multinational consulting companies and one university administrative department, all located in Georgia, USA.Participants Employees opted into the study by accepting the invitation on a link sent via email.Main Outcome The outcome was median number of contacts per person per day. This was stratified by day of data collection, age, sex, race and ethnicity.Results Of 3,835 employees approached, 357 (9.3%) completed the first day of contact diary of which 304 completed both days of contact diary. There was a median of 2 contacts (IQR: 1-4, range: 0-21) per respondent on both day one and two. The majority (55%) of contacts involved conversation only, occurred at home (64%), and cumulatively lasted more than 4 hours (38%). Most contacts were repeated, and within same age groups, though participants aged 30-59 years reported substantial inter-generational mixing with children.Conclusion Participating employees in 3 surveyed workplaces reported few contacts, similar to studies from the UK and China when shelter-in-place orders were in effect during the pandemic. Many contacts were repeated which may limit the spread of infection. Future rounds are planned to assess changes in contact patterns when employees resume work in the office after the lockdown due to COVID-19 pandemic.Competing Interest StatementThe authors have declared no competing interest.Funding StatementCenters for Disease Control and Prevention, Atlanta, Georgia (Comprehensively profiling social mixing patterns in workplace settings to model pandemic influenza transmission; U01-CK000572)Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:Ethical approval was given by Yale University (IRB number 2000026906).All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable.YesAll de-identified data and code used for analysis are available in Github through the link provided. https://github.com/lopmanlab/corpmix |
A Public Health Research Agenda for Managing Infodemics: Methods and Results of the First WHO Infodemiology Conference.
Calleja N , AbdAllah A , Abad N , Ahmed N , Albarracin D , Altieri E , Anoko JN , Arcos R , Azlan AA , Bayer J , Bechmann A , Bezbaruah S , Briand SC , Brooks I , Bucci LM , Burzo S , Czerniak C , De Domenico M , Dunn AG , Ecker UKH , Espinosa L , Francois C , Gradon K , Gruzd A , Gülgün BS , Haydarov R , Hurley C , Astuti SI , Ishizumi A , Johnson N , Johnson Restrepo D , Kajimoto M , Koyuncu A , Kulkarni S , Lamichhane J , Lewis R , Mahajan A , Mandil A , McAweeney E , Messer M , Moy W , Ndumbi Ngamala P , Nguyen T , Nunn M , Omer SB , Pagliari C , Patel P , Phuong L , Prybylski D , Rashidian A , Rempel E , Rubinelli S , Sacco P , Schneider A , Shu K , Smith M , Sufehmi H , Tangcharoensathien V , Terry R , Thacker N , Trewinnard T , Turner S , Tworek H , Uakkas S , Vraga E , Wardle C , Wasserman H , Wilhelm E , Würz A , Yau B , Zhou L , Purnat TD . JMIR Infodemiology 2021 1 (1) e30979 BACKGROUND: An infodemic is an overflow of information of varying quality that surges across digital and physical environments during an acute public health event. It leads to confusion, risk-taking, and behaviors that can harm health and lead to erosion of trust in health authorities and public health responses. Owing to the global scale and high stakes of the health emergency, responding to the infodemic related to the pandemic is particularly urgent. Building on diverse research disciplines and expanding the discipline of infodemiology, more evidence-based interventions are needed to design infodemic management interventions and tools and implement them by health emergency responders. OBJECTIVE: The World Health Organization organized the first global infodemiology conference, entirely online, during June and July 2020, with a follow-up process from August to October 2020, to review current multidisciplinary evidence, interventions, and practices that can be applied to the COVID-19 infodemic response. This resulted in the creation of a public health research agenda for managing infodemics. METHODS: As part of the conference, a structured expert judgment synthesis method was used to formulate a public health research agenda. A total of 110 participants represented diverse scientific disciplines from over 35 countries and global public health implementing partners. The conference used a laddered discussion sprint methodology by rotating participant teams, and a managed follow-up process was used to assemble a research agenda based on the discussion and structured expert feedback. This resulted in a five-workstream frame of the research agenda for infodemic management and 166 suggested research questions. The participants then ranked the questions for feasibility and expected public health impact. The expert consensus was summarized in a public health research agenda that included a list of priority research questions. RESULTS: The public health research agenda for infodemic management has five workstreams: (1) measuring and continuously monitoring the impact of infodemics during health emergencies; (2) detecting signals and understanding the spread and risk of infodemics; (3) responding and deploying interventions that mitigate and protect against infodemics and their harmful effects; (4) evaluating infodemic interventions and strengthening the resilience of individuals and communities to infodemics; and (5) promoting the development, adaptation, and application of interventions and toolkits for infodemic management. Each workstream identifies research questions and highlights 49 high priority research questions. CONCLUSIONS: Public health authorities need to develop, validate, implement, and adapt tools and interventions for managing infodemics in acute public health events in ways that are appropriate for their countries and contexts. Infodemiology provides a scientific foundation to make this possible. This research agenda proposes a structured framework for targeted investment for the scientific community, policy makers, implementing organizations, and other stakeholders to consider. |
Drivers of COVID-19 policy stringency in 175 countries and territories: COVID-19 cases and deaths, gross domestic products per capita, and health expenditures.
Jalloh MF , Zeebari Z , Nur SA , Prybylski D , Nur AA , Hakim AJ , Winters M , Steinhardt LC , Gatei W , Omer SB , Brewer NT , Nordenstedt H . J Glob Health 2022 12 05049 BACKGROUND: New data on COVID-19 may influence the stringency of containment policies, but these potential effect are not understood. We aimed to understand the associations of new COVID-19 cases and deaths with policy stringency globally and regionally. METHODS: We modelled the marginal effects of new COVID-19 cases and deaths on policy stringency (scored 0-100) in 175 countries and territories, adjusting for gross domestic product (GDP) per capita and health expenditure (% of GDP), and public expenditure on health. The time periods examined were March to August 2020, September 2020 to February 2021, and March to August 2021. RESULTS: Policy response to new cases and deaths was faster and more stringent early in the COVID-19 pandemic (March to August 2020) compared to subsequent periods. New deaths were more strongly associated with stringent policies than new cases. In an average week, one new death per 100000 people was associated with a stringency increase of 2.1 units in the March to August 2020 period, 1.3 units in the September 2020 to February 2021 period, and 0.7 units in the March to August 2021 period. New deaths in Africa and the Western Pacific were associated with more stringency than in other regions. Higher health expenditure as a percentage of GDP was associated with less stringent policies. Similarly, higher public expenditure on health by governments was mostly associated with less stringency across all three periods. GDP per capita did not have consistent patterns of associations with stringency. CONCLUSIONS: The stringency of COVID-19 policies was more strongly associated with new deaths than new cases. Our findings demonstrate the need for enhanced mortality surveillance to ensure policy alignment during health emergencies. Countries that invest less in health or have a lower public expenditure on health may be inclined to enact more stringent policies. This new empirical understanding of COVID-19 policy drivers can help public health officials anticipate and shape policy responses in future health emergencies. |
Factors influencing the decision to receive seasonal influenza vaccination among US corporate non-healthcare workers.
Aguolu OG , Willebrand K , Elharake JA , Qureshi HM , Kiti MC , Liu CY , Restrepo Mesa A , Nelson K , Jenness S , Melegaro A , Ahmed F , Yildirim I , Malik FA , Lopman B , Omer SB . Hum Vaccin Immunother 2022 18 (6) 2122379 Influenza causes significant mortality and morbidity in the United States (US). Employees are exposed to influenza at work and can spread it to others. The influenza vaccine is safe, effective, and prevents severe outcomes; however, coverage among US adults (50.2%) is below Healthy People 2030 target of 70%. These highlights need for more effective vaccination promotion interventions. Understanding predictors of vaccination acceptance could inform vaccine promotion messages, improve coverage, and reduce illness-related work absences. We aimed to identify factors influencing influenza vaccination among US non-healthcare workers. Using mixed-methods approach, we evaluated factors influencing influenza vaccination among employees in three US companies during April-June 2020. Survey questions were adapted from the WHO seasonal influenza survey. Most respondents (n = 454) were women (272, 59.9%), 20-39 years old (n = 250, 55.1%); white (n = 254, 56.0%); had a college degree (n = 431, 95.0%); and reported receiving influenza vaccine in preceding influenza season (n = 297, 65.4%). Logistic regression model was statistically significant, X (16, N = 450) = 31.6, p = .01. Education [(OR) = 0.3, 95%CI = 0.1-0.6)] and race (OR = 0.4, 95%CI = 0.2-0.8) were significant predictors of influenza vaccine acceptance among participants. The majority had favorable attitudes toward influenza vaccination and reported that physician recommendation would influence their vaccination decisions. Seven themes were identified in qualitative analysis: "Protecting others" (109, 24.0%), "Protecting self" (105, 23.1%), "Vaccine accessibility" (94, 20.7%), "Education/messaging" (71, 15.6%), "Policies/requirements" (15, 3.3%), "Reminders" (9, 2.0%), and "Incentives" (3, 0.7%). Our findings could facilitate the development of effective influenza vaccination promotion messages and programs for employers, and workplace vaccination programs for other diseases such as COVID-19, by public health authorities. | Influenza causes significant mortality and morbidity in the United States (US).The US working-age group (18–64-year-old) bears a huge burden of influenza annually.Influenza vaccination coverage in the working-age group is low.Physicians and employers can influence vaccine acceptance of working adults.Employers can consider practical steps, e.g., incentivizing, or offering vaccine onsite. | eng |
Development of effective messages to promote maternal immunization in Kenya
Frew PM , Gonzalez-Casanova I , Otieno NA , Malik FA , Fenimore VL , Owino D , Adero MO , Atito RO , Bigogod G , Chaves SS , Verani JR , AlainWiddowson M , Omer SB . Vaccine 2022 40 (27) 3761-3770 OBJECTIVES: This study evaluated messages and communication approaches for maternal immunization uptake in Kenya. We identified persuasive communication aspects that would inform maternal immunization attitudes, intent, and vaccine uptake. METHODS: We conducted a two-phased mixed methods study with pregnant women and their male partners in three regions of Kenya. Discussions were conducted in English and Swahili languages by trained focus group moderators. Baseline measures included a survey and discussions about potential messages and accompanying visuals. Follow-up focus groups with the same participants included a survey about previously discussed messages, visuals, and communication impressions. The second round of focus groups focused on message preferences developed from the first round, along with rank order discussion for final message selection. Following transcription of focus group discussions, we conducted analyses using NVivo software. Quantitative data analyses included frequencies, factor analyses, reliability assessment, regression modeling, and comparative assessment of rank order. RESULTS: The sample (N=118) included pregnant women (n=91) and their partners (n=27) from diverse Kenyan regions (Bondo/Lwak/Siaya, Mombasa, and Nairobi). A four-factor solution resulted from factor analyses that included subscales "positive ad attitudes" (n=5 items, =0.82), "negative ad attitudes" (n=4 items, =0.75), "ad indifference" (n=2 items, =0.52), and "ad motivation" (n=4 items, =0.71). Overall, the positive ad attitudes factor (=0.61, p=0.03) was the only significant component in the overall model examining message selections ((2)((6))=262.87, p=0.17). Among the tested concepts, we found that source and situational cues had a strong influence on women's attitude formation and intention to obtain recommended maternal vaccinations. With self-acknowledged variations in knowledge, participants were particularly attuned to images of relatable women, providers, and depictions in realistic or actual Kenyan clinical settings. CONCLUSIONS: The results indicated that positive attitudes were shaped by incorporating highly relatable factors in messages. Implications for subsequent campaigns and research directions are discussed. |
Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: a systematic analysis
Li Y , Wang X , Blau DM , Caballero MT , Feikin DR , Gill CJ , Madhi SA , Omer SB , Simões EAF , Campbell H , Pariente AB , Bardach D , Bassat Q , Casalegno JS , Chakhunashvili G , Crawford N , Danilenko D , Do LAH , Echavarria M , Gentile A , Gordon A , Heikkinen T , Huang QS , Jullien S , Krishnan A , Lopez EL , Markić J , Mira-Iglesias A , Moore HC , Moyes J , Mwananyanda L , Nokes DJ , Noordeen F , Obodai E , Palani N , Romero C , Salimi V , Satav A , Seo E , Shchomak Z , Singleton R , Stolyarov K , Stoszek SK , von Gottberg A , Wurzel D , Yoshida LM , Yung CF , Zar HJ , Nair H . Lancet 2022 399 (10340) 2047-2064 BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory infection in young children. We previously estimated that in 2015, 33·1 million episodes of RSV-associated acute lower respiratory infection occurred in children aged 0-60 months, resulting in a total of 118 200 deaths worldwide. Since then, several community surveillance studies have been done to obtain a more precise estimation of RSV associated community deaths. We aimed to update RSV-associated acute lower respiratory infection morbidity and mortality at global, regional, and national levels in children aged 0-60 months for 2019, with focus on overall mortality and narrower infant age groups that are targeted by RSV prophylactics in development. METHODS: In this systematic analysis, we expanded our global RSV disease burden dataset by obtaining new data from an updated search for papers published between Jan 1, 2017, and Dec 31, 2020, from MEDLINE, Embase, Global Health, CINAHL, Web of Science, LILACS, OpenGrey, CNKI, Wanfang, and ChongqingVIP. We also included unpublished data from RSV GEN collaborators. Eligible studies reported data for children aged 0-60 months with RSV as primary infection with acute lower respiratory infection in community settings, or acute lower respiratory infection necessitating hospital admission; reported data for at least 12 consecutive months, except for in-hospital case fatality ratio (CFR) or for where RSV seasonality is well-defined; and reported incidence rate, hospital admission rate, RSV positive proportion in acute lower respiratory infection hospital admission, or in-hospital CFR. Studies were excluded if case definition was not clearly defined or not consistently applied, RSV infection was not laboratory confirmed or based on serology alone, or if the report included fewer than 50 cases of acute lower respiratory infection. We applied a generalised linear mixed-effects model (GLMM) to estimate RSV-associated acute lower respiratory infection incidence, hospital admission, and in-hospital mortality both globally and regionally (by country development status and by World Bank Income Classification) in 2019. We estimated country-level RSV-associated acute lower respiratory infection incidence through a risk-factor based model. We developed new models (through GLMM) that incorporated the latest RSV community mortality data for estimating overall RSV mortality. This review was registered in PROSPERO (CRD42021252400). FINDINGS: In addition to 317 studies included in our previous review, we identified and included 113 new eligible studies and unpublished data from 51 studies, for a total of 481 studies. We estimated that globally in 2019, there were 33·0 million RSV-associated acute lower respiratory infection episodes (uncertainty range [UR] 25·4-44·6 million), 3·6 million RSV-associated acute lower respiratory infection hospital admissions (2·9-4·6 million), 26 300 RSV-associated acute lower respiratory infection in-hospital deaths (15 100-49 100), and 101 400 RSV-attributable overall deaths (84 500-125 200) in children aged 0-60 months. In infants aged 0-6 months, we estimated that there were 6·6 million RSV-associated acute lower respiratory infection episodes (4·6-9·7 million), 1·4 million RSV-associated acute lower respiratory infection hospital admissions (1·0-2·0 million), 13 300 RSV-associated acute lower respiratory infection in-hospital deaths (6800-28 100), and 45 700 RSV-attributable overall deaths (38 400-55 900). 2·0% of deaths in children aged 0-60 months (UR 1·6-2·4) and 3·6% of deaths in children aged 28 days to 6 months (3·0-4·4) were attributable to RSV. More than 95% of RSV-associated acute lower respiratory infection episodes and more than 97% of RSV-attributable deaths across all age bands were in low-income and middle-income countries (LMICs). INTERPRETATION: RSV contributes substantially to morbidity and mortality burden globally in children aged 0-60 months, especially during the first 6 months of life and in LMICs. We highlight the striking overall mortality burden of RSV disease worldwide, with one in every 50 deaths in children aged 0-60 months and one in every 28 deaths in children aged 28 days to 6 months attributable to RSV. For every RSV-associated acute lower respiratory infection in-hospital death, we estimate approximately three more deaths attributable to RSV in the community. RSV passive immunisation programmes targeting protection during the first 6 months of life could have a substantial effect on reducing RSV disease burden, although more data are needed to understand the implications of the potential age-shifts in peak RSV burden to older age when these are implemented. FUNDING: EU Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU). |
Association of community engagement with vaccination confidence and uptake: A cross-sectional survey in Sierra Leone, 2019
Jalloh MF , Sengeh P , Ibrahim N , Kulkarni S , Sesay T , Eboh V , Jalloh MB , AbuPratt S , Webber N , Thomas H , Kaiser R , Singh T , Prybylski D , Omer SB , Brewer NT , Wallace AS . J Glob Health 2022 12 04006 BACKGROUND: The 2014-2016 Ebola epidemic disrupted childhood immunization in Sierra Leone, Liberia, and Guinea. After the epidemic, the Government of Sierra Leone prioritized community engagement to increase vaccination confidence and uptake. To support these efforts, we examined potential drivers of vaccination confidence and uptake in Sierra Leone. METHODS: We conducted a population-based household survey with primary caregivers of children in a birth cohort of 12 to 23 months in four districts with low vaccination coverage in Sierra Leone in 2019. Modified Poisson regression modeling with robust variance estimation was used to examine if perceived community engagement in planning the immunization program in the community was associated with vaccination confidence and having a fully vaccinated child. RESULTS: The sample comprised 621 age-eligible children and their caregivers (91% response rate). Half of the caregivers (52%) reported that it usually takes too long to get to the vaccination site, and 36% perceived that health workers expect money for vaccination services that are supposed to be given at no charge. When mothers were the decision-makers of the children's vaccination, 80% of the children were fully vaccinated versus 69% when fathers were the decision-makers and 56% when other relatives were the decision-makers. Caregivers with high confidence in vaccination were more likely to have fully vaccinated children compared to caregivers with low confidence (78% versus 53%). For example, caregivers who thought vaccines are 'very much' safe were more likely to have fully vaccinated children than those who thought vaccines are 'somewhat' safe (76% versus 48%). Overall, 53% of caregivers perceived high level of community engagement, 41% perceived medium level of engagement, and 6% perceived low level of engagement. Perceiving high community engagement was associated with expressing high vaccination confidence (adjusted prevalence ratio (aPR)=2.60; 95% confidence interval (CI)=1.67-4.04) and having a fully vaccinated child (aPR=1.67; 95% CI=1.18-2.38). CONCLUSIONS: In these four low coverage districts in Sierra Leone, the perceived level of community engagement was strongly associated with vaccination confidence among caregivers and vaccination uptake among children. We have provided exploratory cross-sectional evidence to inform future longitudinal assessments to further investigate the potential causal effect of community engagement on vaccination confidence and uptake. |
Social contact patterns among employees in 3 U.S. companies during early phases of the COVID-19 pandemic, April to June 2020.
Kiti MC , Aguolu OG , Liu CY , Mesa AR , Regina R , Woody M , Willebrand K , Couzens C , Bartelsmeyer T , Nelson KN , Jenness S , Riley S , Melegaro A , Ahmed F , Malik F , Lopman BA , Omer SB . Epidemics 2021 36 100481 We measured contact patterns using online diaries for 304 employees of 3 U.S. companies working remotely. The median number of daily contacts was 2 (IQR 1-4); majority were conversation (55 %), occurred at home (64 %) and lasted >4 h (38 %). These data are crucial for modeling outbreak control among the workforces. |
Decision-making process for introduction of maternal vaccines in Kenya, 2017-2018
Otieno NA , Malik FA , Nganga SW , Wairimu WN , Ouma DO , Bigogo GM , Chaves SS , Verani JR , Widdowson MA , Wilson AD , Bergenfeld I , Gonzalez-Casanova I , Omer SB . Implement Sci 2021 16 (1) 39 BACKGROUND: Maternal immunization is a key strategy for reducing morbidity and mortality associated with infectious diseases in mothers and their newborns. Recent developments in the science and safety of maternal vaccinations have made possible development of new maternal vaccines ready for introduction in low- and middle-income countries. Decisions at the policy level remain the entry point for maternal immunization programs. We describe the policy and decision-making process in Kenya for the introduction of new vaccines, with particular emphasis on maternal vaccines, and identify opportunities to improve vaccine policy formulation and implementation process. METHODS: We conducted 29 formal interviews with government officials and policy makers, including high-level officials at the Kenya National Immunization Technical Advisory Group, and Ministry of Health officials at national and county levels. All interviews were recorded and transcribed. We analyzed the qualitative data using NVivo 11.0 software. RESULTS: All key informants understood the vaccine policy formulation and implementation processes, although national officials appeared more informed compared to county officials. County officials reported feeling left out of policy development. The recent health system decentralization had both positive and negative impacts on the policy process; however, the negative impacts outweighed the positive impacts. Other factors outside vaccine policy environment such as rumours, sociocultural practices, and anti-vaccine campaigns influenced the policy development and implementation process. CONCLUSIONS: Public policy development process is complex and multifaceted by its nature. As Kenya prepares for introduction of other maternal vaccines, it is important that the identified policy gaps and challenges are addressed. |
Effectiveness of gas and chimney biomass stoves for reducing household air pollution pregnancy exposure in Guatemala: Sociodemographic effect modifiers
Grajeda LM , Thompson LM , Arriaga W , Canuz E , Omer SB , Sage M , Azziz-Baumgartner E , Bryan JP , McCracken JP . Int J Environ Res Public Health 2020 17 (21) Household air pollution (HAP) due to solid fuel use during pregnancy is associated with adverse birth outcomes. The real-life effectiveness of clean cooking interventions has been disappointing overall yet variable, but the sociodemographic determinants are not well described. We measured personal 24-h PM(2.5) (particulate matter <2.5 µm in aerodynamic diameter) thrice in pregnant women (n = 218) gravimetrically with Teflon filter, impactor, and personal pump setups. To estimate the effectiveness of owning chimney and liquefied petroleum gas (LPG) stoves (i.e., proportion of PM(2.5) exposure that would be prevented) and to predict subject-specific typical exposures, we used linear mixed-effects models with log (PM(2.5)) as dependent variable and random intercept for subject. Median (IQR) personal PM(2.5) in µg/m(3) was 148 (90-249) for open fire, 78 (51-125) for chimney stove, and 55 (34-79) for LPG stoves. Adjusted effectiveness of LPG stoves was greater in women with ≥6 years of education (49% (95% CI: 34, 60)) versus <6 years (26% (95% CI: 5, 42)). In contrast, chimney stove adjusted effectiveness was greater in women with <6 years of education (50% (95% CI: 38, 60)), rural residence (46% (95% CI: 34, 55)) and lowest SES (socio-economic status) quartile (59% (95% CI: 45, 70)) than ≥6 years education (16% (95% CI: 22, 43)), urban (23% (95% CI: -164, 42)) and highest SES quartile (-44% (95% CI: -183, 27)), respectively. A minority of LPG stove owners (12%) and no chimney owner had typical exposure below World Health Organization Air Quality guidelines (35 μg/m(3)). Although having a cleaner stove alone typically does not lower exposure enough to protect health, understanding sociodemographic determinants of effectiveness may lead to better targeting, implementation, and adoption of interventions. |
Knowledge and attitudes towards influenza and influenza vaccination among pregnant women in Kenya
Otieno NA , Nyawanda B , Otiato F , Adero M , Wairimu WN , Atito R , Wilson AD , Gonzalez-Casanova I , Malik FA , Verani JR , Widdowson MA , Omer SB , Chaves SS . Vaccine 2020 38 (43) 6832-6838 BACKGROUND: Influenza vaccination during pregnancy benefits mothers and children. Kenya and other low- and middle-income countries have no official influenza vaccination policies to date but are moving towards issuing such policies. Understanding determinants of influenza vaccine uptake during pregnancy in these settings is important to inform policy decisions and vaccination rollout. METHODS: We interviewed a convenience sample of women at antenatal care facilities in four counties (Nairobi, Mombasa, Marsabit, Siaya) in Kenya. We described knowledge and attitudes regarding influenza vaccination and assessed factors associated with willingness to receive influenza vaccine. RESULTS: We enrolled 507 pregnant women, median age was 26 years (range 15-43). Almost half (n = 240) had primary or no education. Overall, 369 (72.8%) women had heard of influenza. Among those, 288 (78.1%) believed that a pregnant woman would be protected if vaccinated, 252 (68.3%) thought it was safe to receive a vaccine while pregnant, and 223 (60.4%) believed a baby would be protected if mother was vaccinated. If given opportunity, 309 (83.7%) pregnant women were willing to receive the vaccine. Factors associated with willingness to receive influenza vaccine were mothers' belief in protective effect (OR 3.87; 95% CI 1.56, 9.59) and safety (OR 5.32; 95% CI 2.35, 12.01) of influenza vaccines during pregnancy. CONCLUSION: Approximately one third of pregnant women interviewed had never heard of influenza. Willingness to receive influenza vaccine was high among women who had heard about influenza. If the Kenyan government recommends influenza vaccine for pregnant women, mitigation of safety concerns and education on the benefits of vaccination could be the most effective strategies to improve vaccine acceptance. |
Adverse events following quadrivalent meningococcal diphtheria toxoid conjugate vaccine (Menactra®) reported to the Vaccine Adverse Event Reporting System (VAERS), 2005-2016.
Myers TR , McNeil MM , Ng CS , Li R , Marquez PL , Moro PL , Omer SB , Cano MV . Vaccine 2020 38 (40) 6291-6298 BACKGROUND: Post marketing safety evaluations of quadrivalent meningococcal diphtheria-toxoid conjugate vaccine (MenACWY-D) have focused on post-vaccination risk of Guillain Barré syndrome (GBS), adverse events (AEs) after maternal vaccination, and comparative studies with the newer quadrivalent meningococcal CRM(197) conjugate vaccine (MenACWY-CRM). To provide an updated general safety assessment, we reviewed reports of AEs following MenACWY-D submitted to the Vaccine Adverse Event Reporting System (VAERS). METHODS: VAERS is a national spontaneous reporting vaccine safety surveillance system co-administered by the Centers for Disease Control and Prevention and the U.S. Food and Drug Administration. We searched the VAERS database for U.S. reports of AEs after administration of MenACWY-D from January 2005 through June 2016. We conducted clinical reviews of serious reports after MenACWY-D administered alone, reports of MenACWY-D use during pregnancy, and reports of selected pre-specified outcomes. We screened for disproportionate reporting of AEs after MenACWY-D using empirical Bayesian data mining. RESULTS: VAERS received 13,075 U.S. reports after receipt of MenACWY-D; most (86%) described vaccination in adolescents, were classified as non-serious (94%), and described AEs consistent with pre-licensure studies. We did not find any evidence that reported deaths were related to vaccination. In serious reports, GBS and meningococcal infection were the most commonly reported medical conditions. Many reports of MenACWY-D use during pregnancy described inadvertent vaccination; most (61%) did not report any AE. CONCLUSIONS: Findings from our comprehensive review of reports to VAERS following MenACWY-D are consistent with data from pre-licensure studies and provide further reassurance on the safety of MenACWY-D. |
Association between vaccine exemption policy change in California and adverse event reporting
Hause AM , Hesse EM , Ng C , Marquez P , McNeil MM , Omer SB . Pediatr Infect Dis J 2020 39 (5) 369-373 BACKGROUND: California Senate Bill 277 (SB277) eliminated non-medical immunization exemptions. Since its introduction on February 19, 2015, the rate of medical exemptions in the state has increased. Filing a report to Vaccine Adverse Event Reporting System (VAERS) may be perceived as helpful in applying for a medical exemption. Our objective was to describe trends in reporting to VAERS from California coincident with introduction of SB277. METHODS: This was a retrospective study of Californian children <18 years for whom a VAERS report was submitted between June 1, 2011 and July 31, 2018. VAERS is a national, passive, vaccine safety surveillance program co-managed by Centers for Disease Control and Prevention and FDA. The main outcomes were the proportion of VAERS reports submitted by parents (vs. other reporter types), time from immunization to VAERS report (reporting time), and adverse event type. We also performed spatial analysis, mapping reports pre- and post-mandate by county. RESULTS: We identified 6703 VAERS reports from California during the study period. The proportion of reports received from parents increased after implementation of SB277, from 14% to 23%. The median reporting time by parents increased from 9 days in 2013-2014 to 31 days in 2016-2017. After the introduction of SB277, we observed an increase in reports describing behavioral and developmental symptoms among reports submitted >6 months after immunization. CONCLUSIONS: These recent changes in reporting patterns coincident with the introduction of SB277 may indicate that more parents are using VAERS to assist in applying for a medical exemption for their child. |
Drivers and barriers of vaccine acceptance among pregnant women in Kenya
Otieno NA , Otiato F , Nyawanda B , Adero M , Wairimu WN , Ouma D , Atito R , Wilson A , Gonzalez-Casanova I , Malik FA , Widdowson MA , Omer SB , Chaves SS , Verani JR . Hum Vaccin Immunother 2020 16 (10) 1-9 Maternal vaccination coverage remains suboptimal globally and is lowest in low- and middle-income countries. Attitudes toward maternal vaccines have been characterized in middle-high income settings, however data from African countries are limited. We assessed drivers and barriers of vaccine acceptance among pregnant women in Kenya. We conducted a cross-sectional survey among pregnant women aged 15-49 y. We enrolled a convenience sample of women presenting for antenatal care at seven health-care facilities in four diverse counties (Nairobi, Mombasa, Marsabit, Siaya) of Kenya and from the community in two counties (Nairobi, Siaya). We described frequencies of socio-demographic characteristics of participants and their knowledge, attitudes, and beliefs regarding maternal vaccination. We enrolled 604 pregnant women with a median age of 26.5 y, of whom 48.2% had primary education or less. More than 95% agreed that maternal vaccines are "important for my health" and that getting vaccinated is "a good way to protect myself from disease". The most commonly cited reason in favor of maternal vaccination was disease prevention (53.2%). Fear of side effects to mother/baby (15.1%) was the most frequently reported potential barrier. Influenza vaccine is not in routine use in Kenya; however, 77.8% reported willingness to accept influenza vaccination during pregnancy. Maternal vaccination is well accepted among Kenyan pregnant women. We identified the provision of adequate vaccine information and addressing safety concerns as opportunities to improve maternal vaccine uptake. The expressed willingness to receive a vaccine not currently in routine use bodes well for implementation of new maternal vaccines in Kenya. |
Global burden of respiratory infections associated with seasonal influenza in children under 5 years in 2018: a systematic review and modelling study
Wang X , Li Y , O'Brien KL , Madhi SA , Widdowson MA , Byass P , Omer SB , Abbas Q , Ali A , Amu A , Azziz-Baumgartner E , Bassat Q , Abdullah Brooks W , Chaves SS , Chung A , Cohen C , Echavarria M , Fasce RA , Gentile A , Gordon A , Groome M , Heikkinen T , Hirve S , Jara JH , Katz MA , Khuri-Bulos N , Krishnan A , de Leon O , Lucero MG , McCracken JP , Mira-Iglesias A , Moisi JC , Munywoki PK , Ourohire M , Polack FP , Rahi M , Rasmussen ZA , Rath BA , Saha SK , Simoes EA , Sotomayor V , Thamthitiwat S , Treurnicht FK , Wamukoya M , Yoshida LM , Zar HJ , Campbell H , Nair H . Lancet Glob Health 2020 8 (4) e497-e510 BACKGROUND: Seasonal influenza virus is a common cause of acute lower respiratory infection (ALRI) in young children. In 2008, we estimated that 20 million influenza-virus-associated ALRI and 1 million influenza-virus-associated severe ALRI occurred in children under 5 years globally. Despite this substantial burden, only a few low-income and middle-income countries have adopted routine influenza vaccination policies for children and, where present, these have achieved only low or unknown levels of vaccine uptake. Moreover, the influenza burden might have changed due to the emergence and circulation of influenza A/H1N1pdm09. We aimed to incorporate new data to update estimates of the global number of cases, hospital admissions, and mortality from influenza-virus-associated respiratory infections in children under 5 years in 2018. METHODS: We estimated the regional and global burden of influenza-associated respiratory infections in children under 5 years from a systematic review of 100 studies published between Jan 1, 1995, and Dec 31, 2018, and a further 57 high-quality unpublished studies. We adapted the Newcastle-Ottawa Scale to assess the risk of bias. We estimated incidence and hospitalisation rates of influenza-virus-associated respiratory infections by severity, case ascertainment, region, and age. We estimated in-hospital deaths from influenza virus ALRI by combining hospital admissions and in-hospital case-fatality ratios of influenza virus ALRI. We estimated the upper bound of influenza virus-associated ALRI deaths based on the number of in-hospital deaths, US paediatric influenza-associated death data, and population-based childhood all-cause pneumonia mortality data in six sites in low-income and lower-middle-income countries. FINDINGS: In 2018, among children under 5 years globally, there were an estimated 109.5 million influenza virus episodes (uncertainty range [UR] 63.1-190.6), 10.1 million influenza-virus-associated ALRI cases (6.8-15.1); 870 000 influenza-virus-associated ALRI hospital admissions (543 000-1 415 000), 15 300 in-hospital deaths (5800-43 800), and up to 34 800 (13 200-97 200) overall influenza-virus-associated ALRI deaths. Influenza virus accounted for 7% of ALRI cases, 5% of ALRI hospital admissions, and 4% of ALRI deaths in children under 5 years. About 23% of the hospital admissions and 36% of the in-hospital deaths were in infants under 6 months. About 82% of the in-hospital deaths occurred in low-income and lower-middle-income countries. INTERPRETATION: A large proportion of the influenza-associated burden occurs among young infants and in low-income and lower middle-income countries. Our findings provide new and important evidence for maternal and paediatric influenza immunisation, and should inform future immunisation policy particularly in low-income and middle-income countries. FUNDING: WHO; Bill & Melinda Gates Foundation. |
Patient and provider perspectives on how trust influences maternal vaccine acceptance among pregnant women in Kenya
Nganga SW , Otieno NA , Adero M , Ouma D , Chaves SS , Verani JR , Widdowson MA , Wilson A , Bergenfeld I , Andrews C , Fenimore VL , Gonzalez-Casanova I , Frew PM , Omer SB , Malik FA . BMC Health Serv Res 2019 19 (1) 747 BACKGROUND: Pregnant women and newborns are at high risk for infectious diseases. Altered immunity status during pregnancy and challenges fully vaccinating newborns contribute to this medical reality. Maternal immunization is a strategy to protect pregnant women and their newborns. This study aimed to find out how patient-provider relationships affect maternal vaccine uptake, particularly in the context of a lower middle- income country where limited research in this area exists. METHODS: We conducted semi-structured, in-depth narrative interviews of both providers and pregnant women from four sites in Kenya: Siaya, Nairobi, Mombasa, and Marsabit. Interviews were conducted in either English or one of the local regional languages. RESULTS: We found that patient trust in health care providers (HCPs) is integral to vaccine acceptance among pregnant women in Kenya. The HCP-patient relationship is a fiduciary one, whereby the patients' trusts is primarily rooted in the provider's social position as a person who is highly educated in matters of health. Furthermore, patient health education and provider attitudes are crucial for reinstating and fostering that trust, especially in cases where trust was impeded by rumors, community myths and misperceptions, and religious and cultural factors. CONCLUSION: Patient trust in providers is a strong facilitator contributing to vaccine acceptance among pregnant women in Kenya. To maintain and increase immunization trust, providers have a critical role in cultivating a positive environment that allows for favorable interactions and patient health education. This includes educating providers on maternal immunizations and enhancing knowledge of effective risk communication tactics in clinical encounters. |
Home-based records and vaccination appointment stickers as parental reminders to reduce vaccination dropout in Indonesia: A cluster-randomized controlled trial
Wallace AS , Peetosutan K , Untung A , Ricardo M , Yosephine P , Wannemuehler K , Brown DW , McFarland DA , Orenstein WA , Rosenberg ES , Omer SB , Daniels D . Vaccine 2019 37 (45) 6814-6823 INTRODUCTION: Limited evidence is available about the effectiveness of strategies to remind caregivers when to bring children back for future vaccinations in low- and middle-income country settings. We evaluated the effectiveness of two reminder strategies based on home-based vaccination records (HBR) in Indonesia. METHODS: In this cluster-randomized controlled trial involving 3616 children <1year of age, 90 health facilities were randomly assigned to either a control group or one of two intervention groups: (1) HBR-only group, where healthcare workers provided an HBR to any child without an HBR during a vaccination visit and instructed the caregiver to keep it at home between visits, or (2) HBR+sticker group, where, in addition to HBR provision, healthcare workers placed vaccination appointment reminder stickers on the HBR. The primary outcome was receipt of the third dose of diphtheria-tetanus-pertussis-containing vaccine (DTPcv3) within 7months and the secondary outcome was receipt of a timely DTPcv3 dose. RESULTS: Control group DTPcv3 coverage was 81%. In intention-to-treat analysis, neither intervention group had significantly different DTPcv3 coverage compared with the control group (RR=0.94, 95% confidence interval [CI] 0.87; 1.02 for HBR-only group; RR=0.97, 95% CI 0.90; 1.04 for HBR+sticker group) by study end. However, children in the HBR+sticker group were 50% more likely to have received a DTPcv3 vaccination (RR=1.46, 95% CI 1.02, 2.09) within 60days of DTPcv1 vaccination, compared with children in the control group; children in the HBR-only group were not more likely to have done so (RR=1.05, 95% CI 0.71, 1.55). DISCUSSION: Reminder stickers had an immediate effect on coverage by improving the proportion of children who received a timely DTPcv3 dose but no effect on the proportion who received DTPcv3 after 7months. Coupling reminder stickers with strategies to address other reasons why children do not return for vaccination visits should be further explored. |
Estimation of the incidence of Guillain-Barre syndrome during pregnancy in the United States
Myers TR , McCarthy NL , Panagiotakopoulos L , Omer SB . Open Forum Infect Dis 2019 6 (3) ofz071 Guillain-Barré syndrome (GBS) is an adverse event of interest after vaccination, yet few data are available for background rates during pregnancy. We confirmed 2 cases of incident GBS and estimated an incidence of 2.8 confirmed GBS cases per million person-years (95% confidence interval, 0.5-9.3), indicating rare occurrence. Our findings will help inform safety assessments of Zika vaccines in pregnant populations. |
Accelerating measles and rubella elimination through research and innovation - Findings from the Measles & Rubella Initiative research prioritization process, 2016
Grant GB , Masresha BG , Moss WJ , Mulders MN , Rota PA , Omer SB , Shefer A , Kriss JL , Hanson M , Durrheim DN , Linkins R , Goodson JL . Vaccine 2019 37 (38) 5754-5761 The Measles & Rubella Initiative (M&RI) identified five key strategies to achieve measles and rubella elimination, including research and innovation to support cost-effective operations and improve vaccination and diagnostic tools. In 2016, the M&RI Research and Innovation Working Group (R&IWG) completed a research prioritization process to identify key research questions and update the global research agenda. The R&IWG reviewed meeting reports and strategic planning documents and solicited programmatic inputs from vaccination experts at the program operational level through a web survey, to identify previous research priorities and new research questions. The R&IWG then convened a meeting of experts to prioritize the identified research questions in four strategic areas: (1) epidemiology and economics, (2) surveillance and laboratory, (3) immunization strategies, and (4) demand creation and communications. The experts identified 19 priority research questions in the four strategic areas to address key areas of work necessary to further progress toward elimination. Future commitments from partners will be needed to develop a platform for improved coordination with adequate and predictable resources for research implementation and innovation to address these identified priorities. |
Research priorities for accelerating progress toward measles and rubella elimination identified by a cross-sectional web-based survey
Kriss JL , Grant GB , Moss WJ , Durrheim DN , Shefer A , Rota PA , Omer SB , Masresha BG , Mulders MN , Hanson M , Linkins RW , Goodson JL . Vaccine 2019 37 (38) 5745-5753 BACKGROUND: In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan (GVAP) that set a target to eliminate measles and rubella in five of the six World Health Organization (WHO) regions by 2020. Significant progress has been made toward achieving this goal through intensive efforts by countries and Measles & Rubella Initiative (M&RI) partners. Accelerating progress will require evidence-based approaches to improve implementation of the core strategies in the Global Measles and Rubella Strategic Plan. The M&RI Research and Innovation Working Group (R&IWG) conducted a web-based survey as part of a process to identify measles and rubella research priorities. Survey findings were used to inform discussions during a meeting of experts convened by the M&RI at the Pan American Health Organization in November 2016. METHODS: The cross-sectional web-based survey of scientific and programmatic experts included questions in four main topic areas: (1) epidemiology and economics (epidemiology); (2) new tools for surveillance, vaccine delivery, and laboratory testing (new tools); (3) immunization strategies and outbreak response (strategies); and (4) vaccine demand and communications (demand). Analyses were stratified by the six WHO regions and by global, regional, or national/sub-national level of respondents. RESULTS: The six highest priority research questions selected by survey respondents from the four topic areas were the following: (1) What are the causes of outbreaks in settings with high reported vaccination coverage? (epidemiology); (2) Can affordable diagnostic tests be developed to confirm measles and rubella cases rapidly and accurately at the point of care? (new tools); (3) What are effective strategies for increasing coverage of the routine first dose of measles vaccine administered at 9 or 12months? (strategies); (4) What are effective strategies for increasing coverage of the second dose given after the first year of life? (strategies); (5) How can communities best be engaged in planning, implementing and monitoring health services including vaccinations? (demand); (6) What capacity building is needed for health workers to be able to identify and work more effectively with community leaders? (demand). Research priorities varied by region and by global/regional/national levels for all topic areas. CONCLUSIONS: Research and innovation will be critical to make further progress toward achieving the GVAP measles and rubella elimination goals. The results of this survey can be used to inform decision-making for investments in research activities at the global, regional, and national levels. |
Safety of 9-valent human papillomavirus vaccine administration among pregnant women: Adverse event reports in the Vaccine Adverse Event Reporting System (VAERS), 2014-2017
Landazabal CS , Moro PL , Lewis P , Omer SB . Vaccine 2019 37 (9) 1229-1234 INTRODUCTION: 9-valent human papillomavirus vaccine (9vHPV) was approved by the Food and Drug Administration (FDA) in December 2014. 9vHPV is not recommended during pregnancy, but some women of childbearing age may be inadvertently exposed. This study aims to evaluate reports submitted to the Vaccine Adverse Event Reporting System (VAERS) of pregnant women exposed to 9vHPV. METHODS: We searched the VAERS database, a national post-licensure vaccine safety surveillance system, for reports of pregnant women vaccinated with 9vHPV in the United States between December 10, 2014 and December 31, 2017. Disproportionate reporting of adverse events (AEs) was assessed using proportional reporting ratios (PRRs). RESULTS: A total of 82 pregnancy reports were identified. Sixty reports (73.2%) did not describe an AE and were submitted only to report the vaccine exposure during pregnancy. The most frequently reported pregnancy-specific AE was spontaneous abortion (n=3; 3.7%), followed by vaginal bleeding (n=2; 2.4%). Among non-pregnancy-specific AEs, injection site reaction (n=3; 3.7%) was most common. No disproportionate reporting of any AE was found. DISCUSSION: No unexpected AEs were observed among these pregnancy reports. |
Development of a valid and reliable scale to assess parents' beliefs and attitudes about childhood vaccines and their association with vaccination uptake and delay in Ghana
Wallace AS , Wannemuehler K , Bonsu G , Wardle M , Nyaku M , Amponsah-Achiano K , Dadzie JF , Sarpong FO , Orenstein WA , Rosenberg ES , Omer SB . Vaccine 2019 37 (6) 848-856 BACKGROUND: Parents' attitudes and beliefs in vaccination are important to understand for shaping vaccine acceptance and demand interventions. Little research has focused on developing a validated scale to measure parents' attitudes towards vaccinations in low and middle-income countries; Ghana provided an opportunity develop a caregiver vaccination attitudes scale (CVAS) validated against childhood vaccine compliance. METHODS: We conducted a cluster survey of 373 households with children aged 12-35months of age from Northern Region, Ghana. Caregivers responded to 22 vaccination behavior and belief survey items and provided the child's vaccination status. In exploratory factor analysis (EFA) to assess CVAS content validity, we used parallel analysis to guide the number of factors to extract and principal axis factor analysis for factor extraction. Reliability of the scale was assessed using McDonald's Omega coefficient. Criterion validity of scale and subscales was assessed against receipt of vaccinations by 12months of age and vaccination delay, using number of days undervaccinated. RESULTS: EFA of CVAS responses resulted in removing 11 of 22 survey items due to loadings <0.30 and development of a 5-factor structure with subscales for Vaccine-Preventable Disease (VPD) Awareness, Vaccine Benefits, Past Behavior, Vaccine Efficacy and Safety, and Trust. The 5 factors accounted for 69% of the common variance and omega coefficients were >0.73 for all subscales. Validity analysis indicated that for every unit increase in the parent's scale score, the odds of the child being vaccinated decreased by 0.58 (95% confidence interval [CI]: 0.37, 0.68) and the number of days under-vaccinated increased by 86 (95%CI: 28, 143). The final 3-factor scale included Vaccine Benefits, Past Behavior, and Vaccine Efficacy and Safety. DISCUSSION: The final CVAS included three factors associated with vaccine compliance in Ghana, although several survey items suggested for use in vaccine acceptance scales were dropped. Replicating this study in several country settings will provide additional evidence to assist in refining a tool for use in routine vaccine acceptance and demand surveillance efforts. |
Effectiveness of ten-valent pneumococcal conjugate vaccine against vaccine type invasive pneumococcal disease in Pakistan
Riaz A , Mohiuddin S , Husain S , Yousafzai MT , Muhammad S , Kabir F , Ur Rehman N , Mirza W , Salam B , Nadeem N , Pardhan K , Khan KMA , Raza SJ , Arif F , Iqbal K , Zuberi HK , Whitney CG , Omer SB , Zaidi AKM , Ali A . Int J Infect Dis 2018 80 28-33 OBJECTIVE: To assess PCV10 effectiveness against invasive pneumococcal disease (IPD) due to vaccine serotypes of Streptococcus pneumoniae (Sp) post introduction of vaccine in routine immunization program of Pakistan. METHODS: A matched case-control study was conducted at 16 hospitals in Sindh Province, Pakistan. Children <5years of age (eligible to receive PCV10) who presented with radiographic confirmed pneumonia and/or meningitis were enrolled as cases. PCR for Lyt A gene was conducted on blood (for radiographic pneumonia) and cerebrospinal fluid (for meningitis) samples to detect Sp. The proportion of IPD due to vaccine serotypes (including vaccine-related serogroups) was determined through serial multiplex PCR. For each case, at least five controls were enrolled from children hospitalized at the same institution, matched on age, district, and season. RESULTS: From 92 IPD cases enrolled during July 2013-March 2017, 24 cases (26.0%) were vaccine serotypes. Most case (87.5% of 24) and control (66.4% of 134) children had not received any PCV10 doses. Estimated effectiveness for PCV10 against vaccine type IPD was 72.7% (CI -7.2 to 92.6%) with at least one dose, 78.8% (CI -11.9 to 96.0%) for at least two doses and 81.9% (CI -55.7 to 97.9%) for all three doses of vaccine. INTERPRETATION: The VE point estimates for PCV10 were high and increased with increasing number of doses. However, VE estimates did not reach statistical significance, possibly due to low power. The findings indicate likely impact of vaccine in reducing burden of vaccine type IPD if vaccine uptake can be improved. |
Provider perspectives on demand creation for maternal vaccines in Kenya
Bergenfeld I , Nganga SW , Andrews CA , Fenimore VL , Otieno NA , Wilson AD , Chaves SS , Verani JR , Widdowson MA , Wairimu WN , Wandera SN , Atito RO , Adero MO , Frew PM , Omer SB , Malik FA . Gates Open Res 2018 2 34 Background . Expansion of maternal immunization, which offers some of the most effective protection against morbidity and mortality in pregnant women and neonates, requires broad acceptance by healthcare providers and their patients. We aimed to describe issues surrounding acceptance and demand creation for maternal vaccines in Kenya from a provider perspective. Methods . Nurses and clinical officers were recruited for semi-structured interviews covering resources for vaccine delivery, patient education, knowledge and attitudes surrounding maternal vaccines, and opportunities for demand creation for new vaccines. Interviews were conducted in English and Swahili, transcribed verbatim from audio recordings, and analyzed using codes developed from interview guide questions and emergent themes. Results . Providers expressed favorable attitudes about currently available maternal immunizations and introduction of additional vaccines, viewing themselves as primarily responsible for vaccine promotion and patient education. The importance of educational resources for both patients and providers to maintain high levels of maternal immunization coverage was a common theme. Most identified barriers to vaccine acceptance and delivery were cultural and systematic in nature. Suggestions for improvement included improved patient and provider education, including material resources, and community engagement through religious and cultural leaders. Conclusions . The distribution of standardized, evidence-based print materials for patient education may reduce provider overwork and facilitate in-clinic efforts to inform women about maternal vaccines. Continuing education for providers should address communication surrounding current vaccines and those under consideration for introduction into routine schedules. Engagement of religious and community leaders, as well as male decision-makers in the household, will enhance future acceptance of maternal vaccines. |
Impact of maternally derived pertussis antibody titers on infant whole-cell pertussis vaccine response in a low income setting
Ibrahim R , Ali SA , Kazi AM , Rizvi A , Guterman LB , Bednarczyk RA , Kim E , Park S , Paulos S , Jeyachandran A , Patel D , Gorantla Y , Wong E , Rajam G , Schiffer J , Omer SB . Vaccine 2018 36 (46) 7048-7053 BACKGROUND: Maternal vaccines against pertussis are not yet recommended in the developing world. Besides unclear burden estimates, another concern is that transplacental transfer of maternal pertussis antibodies could result in attenuation of the immune response to whole cell pertussis (DTwP) primary vaccination series in infants. This study was taken up to determine whether higher levels of maternal pertussis antibodies attenuate immune response of infants to DTwP vaccination series given at 6-10-14weeks of age. METHODOLOGY: A total of 261 pregnant women and their infants from four low-income settlements in Karachi, Pakistan were enrolled in this study. The study endpoints were infant antibody titers for Pertussis toxin (PTx), Filamentous hemagglutinin antigen (FHA), Pertactin (PRN) and Fimbriae type 2/3 (FIM) - from birth through 18weeks of age. Cord blood or pre-vaccine pertussis antibody titers indicate the concentration of maternal antibodies transferred to infants. Linear regression models were used to determine the association between higher maternal antibody titers and infant immune response to DTwP vaccine. Geometric Mean Ratio (GMR) was calculated as the ratio of infant antibody titers at specified time points against the maternal antibody titers at the time of delivery. RESULTS: At eighteen weeks of age, the adjusted beta regression coefficient for PTx was 0.06 (95% CI: -0.49-0.61), FHA 0.02 (95% CI: -0.26 -0.29), PRN 0.02 (95%CI -0.38- 0.43), and FIM 0.17 (95%CI: -0.21-0.54). Among infants who received at least two doses of DTwP vaccine, higher maternal antibody titers did not have any attenuating effect on infant post-immunization antibody titers against all four pertussis antigens. CONCLUSION: Maternal pertussis antibodies did not attenuate infant's immune response to pertussis antigens in DTwP primary vaccine given at 6-10-14weeks of age. |
Disparities in Tdap vaccination and vaccine information needs among pregnant women in the United States
Kriss JL , Albert AP , Carter VM , Jiles AJ , Liang JL , Mullen J , Rodriguez L , Howards PP , Orenstein WA , Omer SB , Fisher A . Matern Child Health J 2018 23 (2) 201-211 Objectives The Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists (ACOG) recommend that pregnant women receive the Tdap vaccine during every pregnancy. The objectives of this paper are to evaluate disparities in Tdap vaccination among pregnant women in the U.S., and to assess whether race/ethnicity and other characteristics are associated with factors that inform pregnant women's decisions about Tdap vaccination. Methods We conducted a nationwide cross-sectional web-based survey of pregnant women in the U.S. during June-July 2014. The primary outcome was self-reported vaccination status with Tdap during pregnancy, categorized as vaccinated, unvaccinated with intent to be vaccinated during the current pregnancy, and unvaccinated with no intent to be vaccinated during the current pregnancy. Secondary outcomes included factors that influenced women's decisions about vaccination and information needs. We used multivariable logistic regression models to estimate odds ratios for associations between race/ethnicity and the outcomes. Results Among pregnant women who completed the survey, 41% (95% CI 36-45%) reported that they had received Tdap during the current pregnancy. Among those women in the third trimester at the time of survey, 52% (95% CI 43-60%) had received Tdap during the current pregnancy. Hispanic women had higher Tdap vaccination than white women and black women (53%, p < 0.05, compared with 38 and 36%, respectively). In logistic regression models adjusting for maternal age, geographic region, education, and income, Hispanic women were more likely to have been vaccinated with Tdap compared with white women (aOR 2.29, 95% CI 1.20-4.37). Higher income and residing in the western U.S. were also independently associated with Tdap vaccination during pregnancy. Twenty-six percent of surveyed women had not been vaccinated with Tdap yet but intended to receive the vaccine during the current pregnancy; this proportion did not differ significantly by race/ethnicity. The most common factor that influenced women to get vaccinated was a health care provider (HCP) recommendation. The most common reason for not getting vaccinated was a concern about safety of the vaccine. Conclusions This study found that some disparities exist in Tdap vaccination among pregnant women in the U.S., and HCPs have an important role in providing information and recommendations about the maternal Tdap recommendation to pregnant women so they can make informed vaccination decisions. |
Determining gestational age and preterm birth in rural Guatemala: A comparison of methods
Weinstein JR , Thompson LM , Diaz Artiga A , Bryan JP , Arriaga WE , Omer SB , McCracken JP . PLoS One 2018 13 (3) e0193666 BACKGROUND: Preterm birth is the leading cause of death among children <5 years of age. Accurate determination of prematurity is necessary to provide appropriate neonatal care and guide preventive measures. To estimate the most accurate method to identify infants at risk for adverse outcomes, we assessed the validity of two widely available methods-last menstrual period (LMP) and the New Ballard (NB) neonatal assessment-against ultrasound in determining gestational age and preterm birth in highland Guatemala. METHODS: Pregnant women (n = 188) were recruited with a gestational age <20 weeks and followed until delivery. Ultrasound was performed by trained physicians and LMP was collected during recruitment. NB was performed on infants within 96 hours of birth by trained study nurses. LMP and NB accuracy at determining gestational age and identifying prematurity was assessed by comparing them to ultrasound. RESULTS: By ultrasound, infant mean gestational age at birth was 38.3 weeks (SD = 1.6) with 16% born at less than 37 gestation. LMP was more accurate than NB (mean difference of +0.13 weeks for LMP and +0.61 weeks for NB). However, LMP and NB estimates had low agreement with ultrasound-determined gestational age (Lin's concordance<0.48 for both methods) and preterm birth (kappa<0.29 for both methods). By LMP, 18% were judged premature compared with 6% by NB. LMP underestimated gestational age among women presenting later to prenatal care (0.18 weeks for each additional week). Gestational age for preterm infants was overestimated by nearly one week using LMP and nearly two weeks using NB. New Ballard neuromuscular measurements were more predictive of preterm birth than those measuring physical criteria. CONCLUSION: In an indigenous population in highland Guatemala, LMP overestimated prematurity by 2% and NB underestimated prematurity by 10% compared with ultrasound estimates. New, simple and accurate methods are needed to identify preterm birth in resource-limited settings worldwide. |
Clinical characteristics of hospitalized infants with laboratory-confirmed pertussis in Guatemala
Phadke VK , McCracken JP , Kriss JL , Lopez MR , Lindblade KA , Bryan JP , Garcia ME , Funes CE , Omer SB . J Pediatric Infect Dis Soc 2017 7 (4) 310-316 Background: Pertussis is an important cause of hospitalization and death in infants too young to be vaccinated (aged <2 months). Limited data on infant pertussis have been reported from Central America. The aim of this study was to characterize acute respiratory illnesses (ARIs) attributable to Bordetella pertussis among infants enrolled in an ongoing surveillance study in Guatemala. Methods: As part of a population-based surveillance study in Guatemala, infants aged <2 months who presented with ARI and required hospitalization were enrolled, and nasopharyngeal and oropharyngeal swab specimens were obtained. For this study, these specimens were tested for B pertussis using real-time polymerase chain reaction (PCR). Results: Among 301 infants hospitalized with ARI, we found 11 with pertussis confirmed by PCR (pertussis-positive infants). Compared to pertussis-negative infants, pertussis-positive infants had a higher mean admission white blood cell count (20900 vs 12579 cells/mul, respectively; P = .024), absolute lymphocyte count (11517 vs 5591 cells/mul, respectively; P < .001), rate of admission to the intensive care unit (64% vs 35%, respectively; P = .054), and case fatality rate (18% vs 3%, respectively; P = .014). Ten of the 11 pertussis-positive infants had cough at presentation; the majority (80%) of them had a cough duration of <7 days, and only 1 had a cough duration of >14 days. Fever (temperature ≥ 38 degrees C) was documented in nearly half (45%) of the pertussis-positive infants (range, 38.0-38.4 degrees C). Conclusions: In this study of infants <2 months of age hospitalized with ARI in Guatemala, pertussis-positive infants had a high rate of intensive care unit admission and a higher case fatality rate than pertussis-negative infants. |
Febrile seizure risk after vaccination in children one to five months of age
Duffy J , Hambidge SJ , Jackson LA , Kharbanda EO , Klein NP , Naleway A , Omer SB , Weintraub E . Pediatr Neurol 2017 76 72-78 BACKGROUND: The risk of febrile seizure is temporarily increased for a few days after the administration of certain vaccines in children aged six to 23 months. Our objective was to determine the febrile seizure risk following vaccination in children aged one to five months, when six different vaccines are typically administered. METHODS: We identified emergency department visits and inpatient admissions with International Classification of Diseases, Ninth Revision, febrile seizure codes among children enrolled in nine Vaccine Safety Datalink participating health care organizations from 2006 through 2011. Febrile seizures were confirmed by medical record abstraction. We used the self-controlled risk-interval method to compare the incidence of febrile seizure during postvaccination days 0 to 1 (risk interval) versus days 14 to 20 (control interval). RESULTS: We identified 15 febrile seizure cases that occurred after 585,342 vaccination visits. The case patients were aged three to five months. The patients had received a median of four (range two to six) vaccines simultaneously. The incidence rate ratio of febrile seizure after vaccination was 23 (95% confidence interval 5.13 to 100.8), and the attributable risk was 3.92 (95% confidence interval 1.68 to 6.17) febrile seizure cases per 100,000 persons vaccinated. CONCLUSIONS: Vaccination in children aged three to five months was associated with a large relative risk of febrile seizure on the day of and the day after vaccination, but the risk was small in absolute terms. Postvaccination febrile seizure should not be a concern for the vast majority of children receiving vaccines, but clinicians might take this risk into consideration when evaluating and treating children susceptible to seizures precipitated by fever. |
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