Last data update: Oct 07, 2024. (Total: 47845 publications since 2009)
Records 1-30 (of 65 Records) |
Query Trace: Lafond KE[original query] |
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Estimation of vaccine effectiveness against SARS-CoV-2-associated hospitalization using sentinel surveillance in South Africa
Chiwandire N , Walaza S , von Gottberg A , Wolter N , Du Plessis M , Moosa F , Groome MJ , Nel J , Variava E , Dawood H , Makhasi M , Feldstein LR , Marcenac P , Lafond KE , Samuels AM , Cohen C . Int J Epidemiol 2024 53 (5) BACKGROUND: COVID-19 vaccine effectiveness (VE) studies leveraging systematic surveillance in sub-Saharan Africa are limited. We assessed the effectiveness of two vaccines (Pfizer BNT162b2 and Johnson & Johnson Ad26.COV2.S) against SARS-CoV-2-associated hospitalization in South African adults aged ≥18 years. METHODS: We conducted a test-negative case-control study using pneumonia surveillance data in South Africa. Inpatients with physician-diagnosed lower respiratory tract infection or suspected COVID-19, testing SARS-CoV-2 positive or negative from June 2021-March 2022, were cases or controls, respectively. Fully vaccinated individuals received one Ad26.COV2.S dose or two BNT162b2 doses ≥14-days before enrollment. VE was estimated using multivariable logistic regression for Delta- and Omicron BA.1/BA.2-predominant periods, stratified by age and HIV status. RESULTS: The study included 925 cases and 1890 controls; 38 (4%) cases and 186 (10%) controls were fully vaccinated with BNT162b2, and 30 (3%) cases and 94 (5%) controls with Ad26.COV2.S. The vaccine effectiveness of BNT162b2 against SARS-CoV-2-associated hospitalization over Delta and Omicron BA.1/BA.2 periods was 91% (95% CI: 52%, 98%) and 33% (-16%, 86%), respectively. The vaccine effectiveness of Ad26.COV2.S against hospitalization over Delta and Omicron BA.1/BA.2 periods was 72% (-36% ,94%), and -19% (-130%, 39%), respectively. The vaccine effectiveness of BNT162b2 against hospitalization over the Delta period was 94% (50%, 99%) and 89% (27%, 98%) among adults aged ≥60 years and HIV-uninfected, respectively. CONCLUSIONS: The BNT162b2 vaccine was effective against SARS-CoV-2-associated hospitalization during the Delta period for adults aged ≥18 years, ≥60 years and those HIV-uninfected. VE for Ad26.COV2.S was inconclusive, potentially due to limited sample size or residual confounding. These findings highlight the utility of sentinel surveillance for estimating VE. |
The partnership for international vaccine initiatives: The importance and opportunity to develop influenza vaccination programs in low- and middle-income countries
Bresee JS , Lafond KE . Vaccine 2024 126255 |
Healthcare personnel acceptance and recommendations for influenza vaccine in twelve low- and middle-income countries: A pooled analysis from 2018 to 2020
McCarron M , Marcenac P , Yau TS , Lafond KE , Ebama MS , Duca LM , Sahakyan G , Bino S , Coulibaly D , Emukule G , Khanthamaly V , Zaraket H , Cherkaoui I , Otorbaeva D , Stravidis K , Safarov A , Bettaieb J , Igboh LS , Azziz-Baumgartner E , Vanyan A , Manukyan A , Nelaj E , Preza I , Douba A , N'Gattia A , Tengbriacheu C , Pathammavong C , Alame M , Alj L , Ben Salah A , Lambach P , Bresee JS . Vaccine 2024 125670 BACKGROUND: Although healthcare personnel (HCP) are targeted for influenza vaccination they typically underutilize vaccines especially in low- and middle-income countries. We explored knowledge, attitudes, and practices of HCP about seasonal influenza vaccines (SIV) to identify factors associated with and modifiable barriers to SIV uptake. METHODS: We pooled individual-level data from cross-sectional surveys about SIV conducted among health workers in 12 low- and middle- income countries during 2018-2020 (i.e., Albania, Armenia, Cote d'Ivoire, Kenya, Kyrgyzstan, Lao PDR, Lebanon, Morocco, North Macedonia, Tunisia, Tajikistan, and Uganda). Eleven countries used a standard protocol and questionnaire based on the Health Belief Model to measure perceptions of susceptibility and severity of influenza disease, benefits of, barriers to, and motivators for vaccination. We analyzed attitudes and perceptions among HCP, including acceptance of vaccine for themselves and willingness to recommend vaccines to patients, grouped by the presence/absence of a national influenza vaccination program. Models were adjusted for geographic region. RESULTS: Our analysis included 10,281 HCP from 12 countries representing four of the six World Health Organization regions: African, Eastern Mediterranean, European, and Western Pacific. The sample was distributed across low income (LIC) (3,183, 31 %), lower-middle (LMIC) (4,744, 46 %), and upper-middle income (UMIC) (2,354, 23 %) countries. Half (50 %) of the countries included in the analysis reported SIV use among HCP in both the year of and the year preceding data collection while the remainder had no influenza vaccination program for HCP. Seventy-four percent (6,341) of HCP reported that they would be willing to be vaccinated if the vaccine was provided free of charge. HCP in LICs were willing to pay prices for SIV representing a higher percentage of their country's annual health expenditure per capita (6.26 % [interquartile range, IQR: 3.13-12.52]) compared to HCP in LMICs and UMICs. HCP in countries with no SIV program were also willing to pay a higher percentage for SIV (5.01 % [IQR: 2.24-8.34]) compared to HCP in countries with SIV programs.. Most (85 %) HCP in our analysis would recommend vaccines to their patients, and those who would accept vaccines for themselves were 3 times more likely to recommend vaccines to their patients (OR 3.1 [95 % CI 1·8, 5·2]). CONCLUSION: Increasing uptake of SIV among HCP can amplify positive impacts of vaccination by increasing the likelihood that HCP recommend vaccines to their patients. Successful strategies to achieve increased uptake of vaccines include clear guidance from health authorities, interventions based on behavior change models, and access to vaccine free-of-charge. |
A qualitative assessment of influenza vaccine uptake among children in Kenya
Liku N , Mburu C , Lafond KE , Ebama M , Athman M , Swaleh S , Jewa I , Ngware E , Njenga V , Kiptoo E , Munyao C , Miano C , Anyango E , Thuo S , Matini W , Mirieri H , Otieno N , Athman M , Chanzera P , Awadh Z , Muthoni M , Kingori P , Kariuki Njenga M , Emukule GO , Osoro E , Tabu C , Dawa J . Vaccine X 2024 19 Background: Influenza is a significant contributor to acute respiratory infections (ARI), and children < 5 years are at increased risk of severe influenza disease. In Kenya the influenza vaccine is not included in the Kenya Expanded Programme on Immunization (KEPI). To inform roll-out of a national influenza vaccination program, we implemented an influenza vaccine demonstration project in Nakuru and Mombasa counties in Kenya from 2019 to 2021 and set out to establish factors driving influenza vaccine acceptance and hesitancy among caregivers of children aged 6–23 months. Methods: Using semi-structured questionnaires, we conducted eight focus group discussions among community members and twelve key informant interviews among healthcare workers to elicit both lay and expert opinions. Thematic analysis of the interviews was conducted using the World Health Organization's “3 Cs” model of vaccine hesitancy to determine reasons for acceptance or hesitancy of the influenza vaccine. Results: The influenza vaccine was well received among community members and healthcare workers though concerns were raised. Vaccine hesitancy was fuelled by misconceptions about reasons for introducing the vaccine (confidence), perceptions that influenza was not a serious disease (complacency) and administrative fees required at some facilities (convenience). Despite the use of various advocacy, communication and social mobilisation strategies targeted at educating the community on the influenza disease and importance of vaccination, there remained a perception of inadequate reach of the sensitization among some community members. Contextual factors such as the COVID-19 pandemic affected uptake, and parents expressed concern over the growing number of vaccines recommended for children. Conclusion: Despite lingering concerns, caregivers had their children vaccinated indicating that vaccine hesitancy exists, even among those who accepted the vaccine for their children. Efforts targeted at increasing confidence in and reducing misconceptions towards vaccines through effective communication strategies, are likely to lead to increased vaccine uptake. © 2024 |
Adverse outcomes in patients hospitalized with pneumonia at age 60 or more: A prospective multi-centric hospital-based study in India
Kanungo S , Bhattacharjee U , Prabhakaran AO , Kumar R , Rajkumar P , Bhardwaj SD , Chakrabarti AK , Kumar CPG , Potdar V , Manna B , Amarchand R , Choudekar A , Gopal G , Sarda K , Lafond KE , Azziz-Baumgartner E , Saha S , Dar L , Krishnan A . PLoS One 2024 19 (5) e0297452 BACKGROUND: Limited data exists regarding risk factors for adverse outcomes in older adults hospitalized with Community-Acquired Pneumonia (CAP) in low- and middle-income countries such as India. This multisite study aimed to assess outcomes and associated risk factors among adults aged ≥60 years hospitalized with pneumonia. METHODS: Between December 2018 and March 2020, we enrolled ≥60-year-old adults admitted within 48 hours for CAP treatment across 16 public and private facilities in four sites. Clinical data and nasal/oropharyngeal specimens were collected by trained nurses and tested for influenza, respiratory syncytial virus (RSV), and other respiratory viruses (ORV) using the qPCR. Participants were evaluated regularly until discharge, as well as on the 7th and 30th days post-discharge. Outcomes included ICU admission and in-hospital or 30-day post-discharge mortality. A hierarchical framework for multivariable logistic regression and Cox proportional hazard models identified risk factors (e.g., demographics, clinical features, etiologic agents) associated with critical care or death. FINDINGS: Of 1,090 CAP patients, the median age was 69 years; 38.4% were female. Influenza viruses were detected in 12.3%, RSV in 2.2%, and ORV in 6.3% of participants. Critical care was required for 39.4%, with 9.9% in-hospital mortality and 5% 30-day post-discharge mortality. Only 41% of influenza CAP patients received antiviral treatment. Admission factors independently associated with ICU admission included respiratory rate >30/min, blood urea nitrogen>19mg/dl, altered sensorium, anemia, oxygen saturation <90%, prior cardiovascular diseases, chronic respiratory diseases, and private hospital admission. Diabetes, anemia, low oxygen saturation at admission, ICU admission, and mechanical ventilation were associated with 30-day mortality. CONCLUSION: High ICU admission and 30-day mortality rates were observed among older adults with pneumonia, with a significant proportion linked to influenza and RSV infections. Comprehensive guidelines for CAP prevention and management in older adults are needed, especially with the co-circulation of SARS-CoV-2. |
Estimating averted illnesses from influenza vaccination for children and pregnant women - El Salvador, Panama, and Peru, 2011-2018
Chard AN , Machingaidze C , Loayza S , Gharpure R , Nogareda F , González R , Domínguez R , Tinoco YO , Dawood FS , Carreon JD , Lafond KE , Jara J , Azziz-Baumgartner E , Cozza V , Couto P , Rolfes MA , Tempia S . Vaccine 2024 BACKGROUND: Estimating the burden of disease averted by vaccination can assist policymakers to implement, adjust, and communicate the value of vaccination programs. Demonstrating the use of a newly available modeling tool, we estimated the burden of influenza illnesses averted by seasonal influenza vaccination in El Salvador, Panama, and Peru during 2011-2017 among two influenza vaccine target populations: children aged 6-23 months and pregnant women. METHODS: We derived model inputs, including incidence, vaccine coverage, vaccine effectiveness, and multipliers from publicly available country-level influenza surveillance data and cohort studies. We also estimated changes in illnesses averted when countries' vaccine coverage was achieved using four different vaccine deployment strategies. RESULTS: Among children aged 6-23 months, influenza vaccination averted an estimated cumulative 2,161 hospitalizations, 81,907 medically-attended illnesses, and 126,987 overall illnesses during the study period, with a prevented fraction ranging from 0.3 % to 12.5 %. Among pregnant women, influenza vaccination averted an estimated cumulative 173 hospitalizations, 6,122 medically attended illnesses, and 16,412 overall illnesses, with a prevented fraction ranging from 0.2 % to 10.9 %. Compared to an influenza vaccine campaign with equal vaccine distribution during March-June, scenarios in which total cumulative coverage was achieved in March and April consistently resulted in the greatest increase in averted illness (23 %-3,129 % increase among young children and 22 %-3,260 % increase among pregnant women). DISCUSSION: Influenza vaccination campaigns in El Salvador, Panama, and Peru conducted between 2011 and 2018 prevented hundreds to thousands of influenza-associated hospitalizations and illnesses in young children and pregnant women. Existing vaccination programs could prevent additional illnesses, using the same number of vaccines, by achieving the highest possible coverage within the first two months of an influenza vaccine campaign. |
Costs and cost-effectiveness of influenza illness and vaccination in low- and middle-income countries: A systematic review from 2012 to 2022
Gharpure R , Chard AN , Cabrera Escobar M , Zhou W , Valleau MM , Yau TS , Bresee JS , Azziz-Baumgartner E , Pallas SW , Lafond KE . PLoS Med 2024 21 (1) e1004333 BACKGROUND: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness; (2) costs of influenza vaccination programs; and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist that could hinder global implementation of influenza vaccination programs. METHODS AND FINDINGS: We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus in January 2022 and October 2023 using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2022. Studies were eligible if they (1) presented original, peer-reviewed findings on cost of illness, cost of vaccination program, or cost-effectiveness of vaccination for seasonal influenza; and (2) included data for at least 1 low- or middle-income country. We abstracted general study characteristics and data specific to each of the 3 study types. Of 54 included studies, 26 presented data on cost-effectiveness, 24 on cost-of-illness, and 5 on program costs. Represented countries were classified as upper-middle income (UMIC; n = 12), lower-middle income (LMIC; n = 7), and low-income (LIC; n = 3). The most evaluated target groups were children (n = 26 studies), older adults (n = 17), and persons with chronic medical conditions (n = 12); fewer studies evaluated pregnant persons (n = 9), healthcare workers (n = 5), and persons in congregate living settings (n = 1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest national economic burden, as a percent of gross domestic product and national health expenditure, was reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (88%) interpreted at least 1 scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Key limitations of this work included (1) heterogeneity across included studies; (2) restrictiveness of the inclusion criteria used; and (3) potential for missed influenza burden from use of sentinel surveillance systems. CONCLUSIONS: The 54 studies identified in this review suggest an increased momentum to generate economic evidence about influenza illness and vaccination from low- and middle-income countries during 2012 to 2022. However, given that we observed substantial heterogeneity, continued evaluation of the economic burden of influenza illness and costs/cost-effectiveness of influenza vaccination, particularly in LICs and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed. Use of standardized methodology could facilitate pooling across settings and knowledge sharing to strengthen global influenza vaccination programs. |
Costs of seasonal influenza vaccine delivery in a pediatric demonstration project for children aged 6-23 months - Nakuru and Mombasa Counties, Kenya, 2019-2021
Gharpure R , Akumu AO , Dawa J , Gobin S , Adhikari BB , Lafond KE , Fischer LS , Mirieri H , Mwazighe H , Tabu C , Jalang'o R , Kamau P , Silali C , Kalani R , Oginga P , Jewa I , Njenga V , Ebama MS , Bresee JS , Njenga MK , Osoro E , Meltzer MI , Emukule GO . Vaccine 2023 BACKGROUND: During November 2019-October 2021, a pediatric influenza vaccination demonstration project was conducted in four sub-counties in Kenya. The demonstration piloted two different delivery strategies: year-round vaccination and a four-month vaccination campaign. Our objective was to compare the costs of both delivery strategies. METHODS: Cost data were collected using standardized questionnaires and extracted from government and project accounting records. We reported total costs and costs per vaccine dose administered by delivery strategy from the Kenyan government perspective in 2021 US$. Costs were separated into financial costs (monetary expenditures) and economic costs (financial costs plus the value of existing resources). We also separated costs by administrative level (national, regional, county, sub-county, and health facility) and program activity (advocacy and social mobilization; training; distribution, storage, and waste management; service delivery; monitoring; and supervision). RESULTS: The total estimated cost of the pediatric influenza demonstration project was US$ 225,269 (financial) and US$ 326,691 (economic) for the year-round delivery strategy (30,397 vaccine doses administered), compared with US$ 214,753 (financial) and US$ 242,385 (economic) for the campaign strategy (25,404 doses administered). Vaccine purchase represented the largest proportion of costs for both strategies. Excluding vaccine purchase, the cost per dose administered was US$ 1.58 (financial) and US$ 5.84 (economic) for the year-round strategy and US$ 2.89 (financial) and US$ 4.56 (economic) for the campaign strategy. CONCLUSIONS: The financial cost per dose was 83% higher for the campaign strategy than the year-round strategy due to larger expenditures for advocacy and social mobilization, training, and hiring of surge staff for service delivery. However, the economic cost per dose was more comparable for both strategies (year-round 22% higher than campaign), balanced by higher costs of operating equipment and monitoring activities for the year-round strategy. These delivery cost data provide real-world evidence to inform pediatric influenza vaccine introduction in Kenya. |
Cost of acute respiratory illness episode and its determinants among community-dwelling older adults: a four-site cohort study from India
Krishnan A , Shekhawat K , Ortega-Sanchez IR , Kanungo S , Rajkumar P , Bhardwaj SD , Kumar R , Prabhakaran AO , Gopal G , Chakrabarti AK , Purushothaman GKC , Potdar V , Manna B , Gharpure R , Amarchand R , Choudekar A , Lafond KE , Dar L , Bhattacharjee U , Azziz-Baumgartner E , Saha S . BMJ Public Health 2023 1 (1) e000103 INTRODUCTION: Advocacy for the provision of public health resources, including vaccine for the prevention of acute respiratory illnesses (ARIs) among older adults in India, needs evidence on costs and benefits. Using a cohort of community-dwelling adults aged 60 years and older in India, we estimated the cost of ARI episode and its determinants. METHODS: We enrolled 6016 participants in Ballabgarh, Chennai, Kolkata and Pune from July 2018 to March 2020. They were followed up weekly to identify ARI and classified them as acute upper respiratory illness (AURI) or pneumonia based on clinical features based on British Thoracic Society guidelines. All pneumonia and 20% of AURI cases were asked about the cost incurred on medical consultation, investigation, medications, transportation, food and lodging. The cost of services at public facilities was supplemented by WHO-Choosing Interventions that are Cost-Effective(CHOICE) estimates for 2019. Indirect costs incurred by the affected participant and their caregivers were estimated using human capital approach. We used generalised linear model with log link and gamma family to identify the average marginal effect of key determinants of the total cost of ARI. RESULTS: We included 2648 AURI and 1081 pneumonia episodes. Only 47% (range 36%-60%) of the participants with pneumonia sought care. The mean cost of AURI episode was US$13.9, while that of pneumonia episode was US$25.6, with indirect costs comprising three-fourths of the total. The cost was higher among older men by US$3.4 (95% CI: 1.4 to 5.3), those with comorbidities by US$4.3 (95% CI: 2.8 to 5.7) and those who sought care by US$17.2 (95% CI: 15.1 to 19.2) but not by influenza status. The mean per capita annual cost of respiratory illness was US$29.5. CONCLUSION: Given the high community disease and cost burden of ARI, intensifying public health interventions to prevent and mitigate ARI among this fast-growing older adult population in India is warranted. |
Comparing performance of year-round and campaign-mode influenza vaccination strategies among children aged 6-23 months in Kenya: 2019-2021
Dawa J , Jalang'o R , Mirieri H , Kalani R , Marwanga D , Lafond KE , Muriuki MM , Ejoi J , Chiguba F , Patta S , Amoth P , Okunga E , Tabu C , Chaves SS , Ebama MS , Muthoka P , Njenga V , Kiptoo E , Jewa I , Mwanyamawi R , Bresee J , Njenga MK , Osoro E , Mecca L , Emukule GO . Vaccine 2023 INTRODUCTION: In 2016, the Kenya National Immunization Technical Advisory Group requested additional programmatic and cost effectiveness data to inform the choice of strategy for a national influenza vaccination program among children aged 6-23 months of age. In response, we conducted an influenza vaccine demonstration project to compare the performance of a year-round versus campaign-mode vaccination strategy. Findings from this demonstration project will help identify essential learning lessons for a national program. METHODS: We compared two vaccine delivery strategies: (i) a year-round vaccination strategy where influenza vaccines were administered throughout the year at health facilities. This strategy was implemented in Njoro sub-county in Nakuru (November 2019 to October 2021) and Jomvu sub-county in Mombasa (December 2019 to October 2021), (ii) a campaign-mode vaccination strategy where vaccines were available at health facilities over four months. This strategy was implemented in Nakuru North sub-county in Nakuru (June to September 2021) and Likoni sub-county in Mombasa (July to October 2021). We assessed differences in coverage, dropout rates, vaccine wastage, and operational needs. RESULTS: We observed similar performance between strategies in coverage of the first dose of influenza vaccine (year-round strategy 59.7 %, campaign strategy 63.2 %). The coverage obtained in the year-round sub-counties was similar (Njoro 57.4 %; Jomvu 63.1 %); however, more marked differences between campaign sub-counties were observed (Nakuru North 73.4 %; Likoni 55.2 %). The campaign-mode strategy exceeded the cold chain capacity of participating health facilities, requiring thrice monthly instead of once monthly deliveries, and was associated with a two-fold increase in workload compared to the year-round strategy (168 vaccines administered per day in the campaign strategy versus 83 vaccines administered per day in the year-round strategy). CONCLUSION: Although both strategies had similar coverage levels, the campaign-mode strategy was associated with considerable operational needs that could significantly impact the immunization program. |
Primary series and booster coronavirus disease 2019 vaccine effectiveness in a cohort of healthcare workers in Albania during a BA.1 and BA.2 variant period, January-May 2022
Finci I , Rojas Castro MY , Hasibra I , Sulo J , Fico A , Daja R , Vasili A , Kota M , Preza I , Mühlemann B , Drosten C , Pebody R , Lafond KE , Kissling E , Katz MA , Bino S . Open Forum Infect Dis 2023 10 (10) ofad479 BACKGROUND: Healthcare workers (HCWs) have experienced high rates of coronavirus disease 2019 (COVID-19) morbidity and mortality. We estimated COVID-19 2-dose primary series and monovalent booster vaccine effectiveness (VE) against symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (BA.1 and BA.2) infection among HCWs in 3 Albanian hospitals during January-May 2022. METHODS: Study participants completed weekly symptom questionnaires, underwent polymerase chain reaction (PCR) testing when symptomatic, and provided quarterly blood samples for serology. We estimated VE using Cox regression models (1 - hazard ratio), with vaccination status as the time-varying exposure and unvaccinated HCWs as the reference group, adjusting for potential confounders: age, sex, prior SARS-CoV-2 infection (detected by PCR, rapid antigen test, or serology), and household size. RESULTS: At the start of the analysis period, 76% of 1462 HCWs had received a primary series, 10% had received a booster dose, and 9% were unvaccinated; 1307 (89%) HCWs had evidence of prior infection. Overall, 86% of primary series and 98% of booster doses received were BNT162b2. The median time interval from the second dose and the booster dose to the start of the analysis period was 289 (interquartile range [IQR], 210-292) days and 30 (IQR, 22-46) days, respectively. VE against symptomatic PCR-confirmed infection was 34% (95% confidence interval [CI], -36% to 68%) for the primary series and 88% (95% CI, 39%-98%) for the booster. CONCLUSIONS: Among Albanian HCWs, most of whom had been previously infected, COVID-19 booster dose offered improved VE during a period of Omicron BA.1 and BA.2 circulation. Our findings support promoting booster dose uptake among Albanian HCWs, which, as of January 2023, was only 20%. Clinical Trials Registration. NCT04811391. |
Introducing seasonal influenza vaccine in Bhutan: Country experience and achievements
Wangchuk S , Prabhakaran AO , Dhakal GP , Zangmo C , Gharpure R , Dawa T , Phuntsho S , Burkhardsmeier B , Saha S , Wangmo D , Lafond KE . Vaccine 2023 41 (48) 7259-7264 Bhutan successfully introduced multiple vaccines since the establishment of the Vaccine Preventable Disease Program in 1979. Surveillance and subsequent introduction of influenza vaccination became a public health priority for the Ministry of Health following the influenza A(H1N1)pdm09 pandemic. Sentinel surveillance for influenza in Bhutan began in 2008, and a study of severe acute respiratory infection was conducted in 2017, which found the highest influenza burden in children aged <5 years and adults ≥50 years. Following review of surveillance and burden of disease data, the National Technical Advisory Group presented recommendations to Bhutan's Ministry of Health which approved influenza vaccine introduction for all five high-risk groups in the country. Upon the official launch of the program in June 2018, the Vaccine Preventable Disease Program began planning, budgeting, and procurement processes with technical and financial support from the Partnership for Influenza Vaccine Introduction, the United States Centers for Disease Control and Prevention, the Bhutan Health Trust Fund, and the World Health Organization. Influenza vaccination for high-risk groups was integrated into Bhutan's routine immunization services in all health care facilities beginning in November 2019 and vaccinated all populations in 2020 in response to the COVID-19 pandemic. Coverage levels between 2019 and 2022 were highest in children aged 6-24 months (62.5%-96.9%) and lowest in pregnant women (47.7%-62.5%). Bhutan maintained high coverage levels despite the COVID-19 pandemic by continued provision of influenza vaccine services at health centers during lockdowns, conducting communication and sensitization efforts, and using catch-up campaigns. Bhutan's experience with introducing and scaling up the influenza vaccine program contributed to the country's capacity to rapidly deploy its COVID-19 vaccination program in 2021. |
Estimating the full health and economic benefits of current and future influenza vaccines
Lafond KE , Gharpure R , Dugan VG , Azziz-Baumgartner E . BMC Med 2023 21 (1) 273 In the dynamic landscape of respiratory virus vaccines, it is crucial to assess the value of novel mRNA and combination influenza/COVID-19 vaccines in low- and middle-income countries. Modeling studies, such as the one conducted by Waterlow et al., provide vital information about the cost-benefit potential of these products compared to currently licensed vaccines. However, this approach only accounts for directly measured medically attended influenza-associated illnesses and has two major limitations. First, this method fails to capture the full disease burden of influenza (including non-respiratory and non-medically attended influenza illnesses), which are particularly important drivers of disease burden in infants and older adults. Second, the model does not describe the ancillary benefits of influenza vaccination such as the attenuation of severe disease, prevention of severe non-respiratory outcomes (e.g., myocardial infarctions), or reduced antibiotic use. To obtain a comprehensive understanding of the benefits of influenza vaccines, we must strive to improve the inputs for future modeling-based evaluations. |
Primary series and booster COVID-19 vaccine effectiveness in a cohort of healthcare workers in Albania during a BA.1 and BA.2 variant period, January - May 2022 (preprint)
Finci I , Castro MYR , Hasibra I , Sulo J , Fico A , Daja R , Vasili A , Kota M , Preza I , Muhlemann B , Drosten C , Pebody R , Lafond KE , Kissling E , Katz MA , Bino S . medRxiv 2023 05 Background Healthcare workers (HCWs) have experienced high rates of COVID-19 morbidity and mortality. We estimated COVID-19 two-dose primary series and monovalent booster vaccine effectiveness (VE) against symptomatic SARS-CoV-2 Omicron (BA.1 and BA.2) infection among HCWs in three Albanian hospitals during January-May 2022. Methods Study participants completed weekly symptom questionnaires, underwent PCR testing when symptomatic, and provided quarterly blood samples for serology. We estimated VE using Cox regression models (1-hazard ratio), with vaccination status as the time-varying exposure and unvaccinated HCWs as the reference group, adjusting for potential confounders: age, sex, prior SARS-CoV-2 infection (detected by PCR, rapid-antigen test or serology), and household size. Results At the start of the analysis period, 76% of 1,462 HCWs had received a primary series, 10% had received a booster dose, and 9% were unvaccinated; 1,307 (89%) HCWs had evidence of prior infection. Overall, 86% of primary series and 98% of booster doses received were BNT162b2. The median time interval from the second dose and the booster dose to the start of the analysis period was 289 days (IQR:210-292) and 30 days (IQR:22-46), respectively. VE against symptomatic PCR-confirmed infection was 34% (95%CI: -36;68) for the primary series and 88% (95%CI: 38;98) for the booster. Conclusions Among Albanian HCWs, most of whom had been previously infected, COVID-19 booster dose offered improved VE during a period of Omicron BA.1 and BA.2 circulation. Our findings support promoting booster dose uptake among Albanian HCWs, which, as of January 2023, was only 20%. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license. |
Costs and cost-effectiveness of influenza illness and vaccination in low- and middle-income countries: A systematic review from 2012 to 2021 (preprint)
Gharpure R , Chard AN , Escobar MC , Zhou W , Bresee JS , Azziz-Baumgartner E , Pallas SW , Lafond KE . medRxiv 2023 08 Introduction: Historically, lack of data on cost-effectiveness of influenza vaccination has been identified as a barrier to vaccine use in low- and middle-income countries. We conducted a systematic review of economic evaluations describing (1) costs of influenza illness, (2) costs of influenza vaccination programs, and (3) vaccination cost-effectiveness from low- and middle-income countries to assess if gaps persist. Method(s): We performed a systematic search in Medline, Embase, Cochrane Library, CINAHL, and Scopus using a combination of the following key words: "influenza" AND "cost" OR "economic." The search included studies with publication years 2012 through 2021. We abstracted general study characteristics and data specific to each of the three areas of review. Result(s): Of 50 included studies, 24 presented data on cost-effectiveness, 23 on cost-of-illness, and four on program costs. Represented countries were classified as upper-middle income (UMIC; n=11), lower-middle income (LMIC; n=7), and low-income (LIC; n=3). The most evaluated target groups were children (n=26 studies), older adults (n=16), and persons with chronic medical conditions (n=12); fewer studies evaluated pregnant persons (n=8), healthcare workers (n=4), and persons in congregate living settings (n=1). Costs-of-illness were generally higher in UMICs than in LMICs/LICs; however, the highest total costs, as a percent of gross domestic product and national health expenditure, were reported from an LIC. Among studies that evaluated the cost-effectiveness of influenza vaccine introduction, most (83%) interpreted at least one scenario per target group as either cost-effective or cost-saving, based on thresholds designated in the study. Conclusion(s): Continued evaluation of the economic burden of influenza illness and costs and cost-effectiveness of influenza vaccination, particularly in low-income countries and among underrepresented target groups (e.g., healthcare workers and pregnant persons), is needed; use of standardized methodology could facilitate pooling across settings. Robust, global economic data are critical to design and maintain sustainable influenza vaccination programs. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Vaccine effectiveness of CanSino (Adv5-nCoV) COVID-19 vaccine among childcare workers - Mexico, March-December 2021 (preprint)
Richardson VL , Franco MAC , Marquez AB , Valdez LM , Ceronio LEC , Cruz VC , Gharpure R , Lafond KE , Yau TS , Azziz-Baumgartner E , Avila MH . medRxiv 2022 17 Background: Beginning in March 2021, Mexico vaccinated childcare workers with a single-dose CanSino Biologics (Adv5-nCoV) COVID-19 vaccine. Although CanSino is currently approved for use in 10 Latin American, Asian, and European countries, little information is available about its vaccine effectiveness (VE). Method(s): We evaluated CanSino VE within a childcare worker cohort that included 1,408 childcare facilities. Participants were followed during March-December 2021 and tested through SARS-CoV-2 RT-PCR or rapid antigen test if they developed any symptom compatible with COVID-19. Vaccination status was obtained through worker registries. VE was calculated as 100% x (1-hazard ratio for SARS-CoV-2 infection in fully vaccinated vs. unvaccinated participants), using an Andersen-Gill model adjusted for age, sex, state, and local viral circulation. Result(s): The cohort included 43,925 persons who were mostly (96%) female with a median age of 32 years; 37,646 (86%) were vaccinated with CanSino. During March-December 2021, 2,250 (5%) participants had laboratory-confirmed COVID-19, of whom 25 were hospitalized and 6 died. Adjusted VE was 20% (95% CI = 10-29%) against illness, 76% (42-90%) against hospitalization, and 94% (66-99%) against death. VE against illness declined from 48% (95% CI = 33-61) after 14-60 days following full vaccination to 20% (95% CI = 9-31) after 61-120 days. Conclusion(s): CanSino vaccine was effective at preventing COVID-19 illness and highly effective at preventing hospitalization and death. It will be useful to further evaluate duration of protection and assess the value of booster doses to prevent COVID-19 and severe outcomes. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Nasal shedding of vaccine viruses after immunization with a Russian-backbone live attenuated influenza vaccine in India
Dar L , Krishnan A , Kumar R , Dhakad S , Choudekar A , Bagga S , Sharma A , Kumar A , Jethani J , Saha S , Amarchand R , Kumar R , Choudhary A , Narayan VV , Gopal G , Lafond KE , Lindstrom S . Influenza Other Respir Viruses 2023 17 (6) e13149 BACKGROUND: We present post-vaccination nasal shedding findings from the phase IV, community-based, triple-blinded RCT conducted to assess efficacy of trivalent LAIV and inactivated influenza vaccines in rural north India. METHODS: Children aged 2-10 years received LAIV or intranasal placebo across 2015 and 2016, as per initial allocation. On days 2 and 4 post-vaccination, trained study nurses collected nasal swabs from randomly selected subset of trial participants based on operational feasibility, accounting for 10.0% and 11.4% of enrolled participants in 2015 and 2016, respectively. Swabs were collected in viral transport medium and transported under cold chain to laboratory for testing by reverse transcriptase real-time polymerase chain reaction. RESULTS: In year 1, on day 2 post-vaccination, 71.2% (74/104) of LAIV recipients shed at least one of vaccine virus strains compared to 42.3% (44/104) on day 4. During year 1, on day 2 post-vaccination, LAIV-A(H1N1)pdm09 was detected in nasal swabs of 12% LAIV recipients, LAIV-A(H3N2) in 41%, and LAIV-B in 59%. In year 2, virus shedding was substantially lower; 29.6% (32/108) of LAIV recipients shed one of the vaccine virus strains on day 2 compared to 21.3% on day 4 (23/108). CONCLUSION: At day 2 post-vaccination in year 1, two-thirds of LAIV recipients were shedding vaccine viruses. Shedding of vaccine viruses varied between strains and was lower in year 2. More research is needed to determine the reason for lower virus shedding and vaccine efficacy for LAIV-A(H1N1)pdm09. |
Primary series COVID-19 vaccine effectiveness among healthcare workers in Albania, February-December 2021
Rubin-Smith JE , Castro MYR , Preza I , Hasibra I , Sulo J , Fico A , Daja R , Vasili A , Kota M , Schmid A , Sridhar S , Guseinova A , Boshevska G , Bejtja G , Mühlemann B , Drosten C , Jorgensen P , Pebody R , Kissling E , Lafond KE , Katz MA , Bino S . IJID Reg 2023 8 19-27 BACKGROUND: Healthcare workers have experienced high rates of morbidity and mortality from coronavirus disease 2019 (COVID-19). METHODS: A prospective cohort study was conducted in three Albanian hospitals between 19 February and 14 December 2021. All participants underwent polymerase chain reaction (PCR) and serological testing at enrolment, regular serology throughout, and PCR testing when symptomatic.Vaccine effectiveness (VE) against COVID-19 and against all severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infections (symptomatic or asymptomatic) was estimated. VE was estimated using a Cox regression model, with vaccination status as a time-varying variable. FINDINGS: In total, 1504 HCWs were enrolled in this study; 70% had evidence of prior SARS-CoV-2 infection. VE was 65.1% [95% confidence interval (CI) 37.7-80.5] against COVID-19, 58.2% (95% CI 15.7-79.3) among participants without prior SARS-CoV-2 infection, and 73.6% (95% CI 24.3-90.8) among participants with prior SARS-CoV-2 infection. For BNT162b2 alone, VE was 69.5% (95% CI 44.5-83.2). During the period when the Delta variant was predominant, VE was 67.1% (95% CI 38.3-82.5). VE against SARS-CoV-2 infection for the full study period was 36.9% (95% CI 15.8-52.7). INTERPRETATION: This study found moderate primary series VE against COVID-19 among healthcare workers in Albania. These results support the continued promotion of COVID-19 vaccination in Albania, and highlight the benefits of vaccination in populations with high levels of prior infection. |
Comparisons in the health and economic assessments of using quadrivalent versus trivalent influenza vaccines: A systematic literature review
Warmath CR , Ortega-Sanchez IR , Duca LM , Porter RM , Usher MG , Bresee JS , Lafond KE , Davis WW . Value Health 2023 26 (5) 768-779 OBJECTIVES: Seasonal influenza vaccines protect against 3 (trivalent influenza vaccine [IIV3]) or 4 (quadrivalent influenza vaccine [IIV4]) viruses. IIV4 costs more than IIV3, and there is a trade-off between incremental cost and protection. This is especially the case in low- and middle-income countries (LMICs) with limited budgets; previous reviews have not identified studies of IIV4-IIV3 comparisons in LMICs. We summarized the literature that compared health and economic outcomes of IIV4 and IIV3, focused on LMICs. METHODS: We systematically searched 5 databases for articles published before October 6, 2021, that modeled health or economic effects of IIV4 versus IIV3. We abstracted data and compared findings among countries and models. RESULTS: Thirty-eight studies fit our selection criteria; 10 included LMICs. Most studies (N = 31) reported that IIV4 was cost-saving or cost-effective compared with IIV3; we observed no difference in health or economic outcomes between LMICs and other countries. Based on cost differences of influenza vaccines, only one study compared coverage of IIV3 with IIV4 and reported that the maximum IIV4 price that would still yield greater public health impact than IIV3 was 13% to 22% higher than IIV3. CONCLUSIONS: When vaccination coverage with IIV4 and IIV3 is the same, IIV4 tends to be not only more effective but more cost-effective than IIV3, even with relatively high price differences between vaccine types. Alternatively, where funding is limited as in most LMICs, higher vaccine coverage can be achieved with IIV3 than IIV4, which could result in more favorable health and economic outcomes. |
Factors associated with receipt of COVID-19 vaccination and SARS-CoV-2 seropositivity among healthcare workers in Albania (February 2021June 2022): secondary analysis of a prospective cohort study
Jorgensen P , Schmid A , Sulo J , Preza I , Hasibra I , Kissling E , Fico A , Sridhar S , Rubin-Smith JE , Kota M , Vasili A , Daja R , Nika M , Pebody R , Lafond KE , Katz MA , Bino S . Lancet Reg Health Eur 2023 27 100584 Background: Healthcare workers (HCWs) have been disproportionally affected by COVID-19. We investigated factors associated with two- and three-dose COVID-19 vaccine uptake and SARS-CoV-2 seropositivity among 1504 HCWs enrolled (19 February-7 May 2021) in a prospective COVID-19 vaccine effectiveness cohort in Albania through a secondary analysis. Methods: We collected sociodemographic, occupational, health, prior SARS-CoV-2 infection, and COVID-19 vaccination data from all HCWs at enrollment. Vaccination status was assessed weekly through June 2022. A serum sample was collected from all participants at enrollment and tested for anti-spike SARS-CoV-2 antibodies. We analyzed HCWs characteristics and outcomes using multivariable logistic regression. Findings: By 11 June 2022, 1337 (88.9%) HCWs had received two COVID-19 vaccine doses, of whom 255 (19.1%) received a booster. Factors significantly associated with receiving three doses (adjusted odds ratio (aOR), 95% CIs) were being ≥35 years (35–44 years: 1.76 (1.05–2.97); 45–54 years: 3.11 (1.92–5.05); ≥55 years: 3.38 (2.04–5.59)) and vaccinated against influenza (1.78; 1.20–2.64). Booster dose receipt was lower among females (0.58; 0.41–0.81), previously infected (0.67; 0.48–0.93), nurses and midwives (0.31; 0.22–0.45), and support staff (0.19; 0.11–0.32). Overall 1076 (72%) were SARS-CoV-2 seropositive at enrollment. Nurses and midwifes (1.45; 1.05–2.02), support staff (1.57; 1.03–2.41), and HCWs performing aerosol-generating procedures (AGPs) (1.40; 1.01–1.94) had higher odds of being seropositive, while smokers had reduced odds (0.55; 0.40–0.75). Interpretation: In a large cohort of Albanian HCWs, COVID-19 vaccine booster dose uptake was very low, particularly among younger, female, and non-physician HCWs, despite evidence demonstrating the added benefit of boosters in preventing infection and severe disease. Reasons behind these disparities should be explored to develop targeted strategies in order to promote uptake in this critical population. SARS-CoV-2 seroprevalence was higher among non-physicians and HCWs performing APGs. A better understanding of the factors contributing to these differences is needed to inform interventions that could reduce infections in the future. Funding: This study was funded by the Task Force for Global Health (US Centers for Disease Control (CDC) cooperative agreement # NU51IP000873) and the World Health Organization, Regional Office for Europe. © 2023 World Health Organization |
Leveraging International Influenza Surveillance Systems and programs during the COVID-19 pandemic
Marcenac P , McCarron M , Davis W , Igboh LS , Mott JA , Lafond KE , Zhou W , Sorrells M , Charles MD , Gould P , Arriola CS , Veguilla V , Guthrie E , Dugan VG , Kondor R , Gogstad E , Uyeki TM , Olsen SJ , Emukule GO , Saha S , Greene C , Bresee JS , Barnes J , Wentworth DE , Fry AM , Jernigan DB , Azziz-Baumgartner E . Emerg Infect Dis 2022 28 (13) S26-s33 A network of global respiratory disease surveillance systems and partnerships has been built over decades as a direct response to the persistent threat of seasonal, zoonotic, and pandemic influenza. These efforts have been spearheaded by the World Health Organization, country ministries of health, the US Centers for Disease Control and Prevention, nongovernmental organizations, academic groups, and others. During the COVID-19 pandemic, the US Centers for Disease Control and Prevention worked closely with ministries of health in partner countries and the World Health Organization to leverage influenza surveillance systems and programs to respond to SARS-CoV-2 transmission. Countries used existing surveillance systems for severe acute respiratory infection and influenza-like illness, respiratory virus laboratory resources, pandemic influenza preparedness plans, and ongoing population-based influenza studies to track, study, and respond to SARS-CoV-2 infections. The incorporation of COVID-19 surveillance into existing influenza sentinel surveillance systems can support continued global surveillance for respiratory viruses with pandemic potential. |
CDC's COVID-19 international vaccine implementation and evaluation program and lessons from earlier vaccine introductions
Soeters HM , Doshi RH , Fleming M , Adegoke OJ , Ajene U , Aksnes BN , Bennett S , Blau EF , Carlton JG , Clements S , Conklin L , Dahlke M , Duca LM , Feldstein LR , Gidudu JF , Grant G , Hercules M , Igboh LS , Ishizumi A , Jacenko S , Kerr Y , Konne NM , Kulkarni S , Kumar A , Lafond KE , Lam E , Longley AT , McCarron M , Namageyo-Funa A , Ortiz N , Patel JC , Perry RT , Prybylski D , Reddi P , Salman O , Sciarratta CN , Shragai T , Siddula A , Sikare E , Tchoualeu DD , Traicoff D , Tuttle A , Victory KR , Wallace A , Ward K , Wong MKA , Zhou W , Schluter WW , Fitter DL , Mounts A , Bresee JS , Hyde TB . Emerg Infect Dis 2022 28 (13) S208-s216 The US Centers for Disease Control and Prevention (CDC) supports international partners in introducing vaccines, including those against SARS-CoV-2 virus. CDC contributes to the development of global technical tools, guidance, and policy for COVID-19 vaccination and has established its COVID-19 International Vaccine Implementation and Evaluation (CIVIE) program. CIVIE supports ministries of health and their partner organizations in developing or strengthening their national capacities for the planning, implementation, and evaluation of COVID-19 vaccination programs. CIVIE's 7 priority areas for country-specific technical assistance are vaccine policy development, program planning, vaccine confidence and demand, data management and use, workforce development, vaccine safety, and evaluation. We discuss CDC's work on global COVID-19 vaccine implementation, including priorities, challenges, opportunities, and applicable lessons learned from prior experiences with Ebola, influenza, and meningococcal serogroup A conjugate vaccine introductions. |
Respiratory syncytial virus among children hospitalized with severe acute respiratory infection in Kashmir, a temperate region in northern India.
Koul PA , Saha S , Kaul KA , Mir H , Potdar V , Chadha M , Iuliano D , Lafond KE , Lal RB , Krishnan A . J Glob Health 2022 12 04050 Background Severe acute respiratory infections (SARI) are a leading cause of hospitalizations in children, especially due to viral pathogens. We studied the prevalence of respiratory viruses among children aged <5 years hospitalized with severe acute respiratory infections (SARI) in Kashmir, India. Methods We conducted a prospective observational study in two tertiary care hospitals from October 2013 to September 2014, systematically enrolling two children aged <5 years with SARI per day. We defined SARI as history of fever or measured fever (≥38°C) and cough with onset in the last 7 days requiring hospitalization for children aged 3-59 months and as physician-diagnosed acute lower respiratory infection for children aged <3 months. Trained study staff screened children within 24 hours of hospitalization for SARI and collected clinical data and nasopharyngeal swabs from enrolled participants. We tested for respiratory syncytial virus (RSV) A and B, influenza viruses, rhinoviruses (HRV)/enteroviruses, adenovirus (AdV), bocavirus (BoV), human metapneumovirus (hMPV) A and B, coronaviruses (OC43, NL65, C229E), and parainfluenza viruses (PIV) 1, 2, 3 and 4 using standardized duplex real-time polymerase chain reaction. Results Among 4548 respiratory illness admissions screened from October 2013 to September 2014, 1026 met the SARI case definition, and 412 were enrolled (ages = 5 days to 58 months; median = 12 months). Among enrolees, 256 (62%) were positive for any virus; RSV was the most commonly detected (n = 118, 29%) followed by HRV/enteroviruses (n = 88, 21%), PIVs (n = 31, 8%), influenza viruses (n = 18, 4%), BoV (n = 15, 4%), coronaviruses (n = 16, 4%), AdV (n = 14, 3%), and hMPV (n = 9, 2%). Fifty-four children had evidence of virus co-detection. Influenza-associated SARI was more common among children aged 1-5 years (14/18, 78%) while most RSV detections occurred in children <12 months (83/118, 70%). Of the RSV viruses typed (n = 116), the majority were type B (94, 80%). Phylogenetic analysis of G gene of RSV showed circulation of the BA9 genotype with 60bp nucleotide duplication. Conclusions Respiratory viruses, especially RSV, contributed to a substantial proportion of SARI hospitalizations among children <5 years in north India. These data can help guide clinicians on appropriate treatment and prevention strategies. © 2022. The Author(s) |
Vaccine effectiveness of CanSino (Adv5-nCoV) COVID-19 vaccine among childcare workers - Mexico, March-December 2021.
Richardson VL , Franco MAC , Márquez AB , Valdez LM , Ceronio LEC , Cruz VC , Gharpure R , Lafond KE , Yau TS , Azziz-Baumgartner E , Ávila MH . Clin Infect Dis 2022 75 S167-S173 BACKGROUND: Beginning in March 2021, Mexico vaccinated childcare workers with a single-dose CanSino Biologics (Adv5-nCoV) COVID-19 vaccine. Although CanSino is currently approved for use in 10 Latin American, Asian, and European countries, little information is available about its vaccine effectiveness (VE). METHODS: We evaluated CanSino VE within a childcare worker cohort that included 1,408 childcare facilities. Participants were followed during March-December 2021 and tested through SARS-CoV-2 RT-PCR or rapid antigen test if they developed any symptom compatible with COVID-19. Vaccination status was obtained through worker registries. VE was calculated as 100% × (1-hazard ratio for SARS-CoV-2 infection in fully vaccinated vs. unvaccinated participants), using an Andersen-Gill model adjusted for age, sex, state, and local viral circulation. RESULTS: The cohort included 43,925 persons who were mostly (96%) female with a median age of 32 years; 37,646 (86%) were vaccinated with CanSino. During March-December 2021, 2,250 (5%) participants had laboratory-confirmed COVID-19, of whom 25 were hospitalized and 6 died. Adjusted VE was 20% (95% CI = 10-29%) against illness, 76% (42-90%) against hospitalization, and 94% (66-99%) against death. VE against illness declined from 48% (95% CI = 33-61) after 14-60 days following full vaccination to 20% (95% CI = 9-31) after 61-120 days. CONCLUSIONS: CanSino vaccine was effective at preventing COVID-19 illness and highly effective at preventing hospitalization and death. It will be useful to further evaluate duration of protection and assess the value of booster doses to prevent COVID-19 and severe outcomes. |
COVID-19 vaccine effectiveness among healthcare workers in Albania (COVE-AL): protocol for a prospective cohort study and cohort baseline data.
Sridhar S , Fico A , Preza I , Hatibi I , Sulo J , Kissling E , Daja R , Ibrahim R , Lemos D , Rubin-Smith J , Schmid A , Vasili A , Valenciano M , Jorgensen P , Pebody R , Lafond KE , Katz MA , Bino S . BMJ Open 2022 12 (3) e057741 INTRODUCTION: Critical questions remain about COVID-19 vaccine effectiveness (VE) in real-world settings, particularly in middle-income countries. We describe a study protocol to evaluate COVID-19 VE in preventing laboratory-confirmed SARS-CoV-2 infection in health workers (HWs) in Albania, an upper-middle-income country. METHODS AND ANALYSIS: In this 12-month prospective cohort study, we enrolled HWs at three hospitals in Albania. HWs are vaccinated through the routine COVID-19 vaccine campaign. Participants completed a baseline survey about demographics, clinical comorbidities, and infection risk behaviours. Baseline serology samples were also collected and tested against the SARS-CoV-2 spike protein, and respiratory swabs were collected and tested for SARS-CoV-2 by RT-PCR. Participants complete weekly symptom questionnaires and symptomatic participants have a respiratory swab collected, which is tested for SARS-CoV-2. At 3, 6, 9 months and 12 months of the study, serology will be collected and tested for antibodies against the SARS-CoV-2 nucleocapsid protein and spike protein. VE will be estimated using a piecewise proportional hazards model (VE=1-HR). BASELINE DATA: From February to May 2021, 1504 HWs were enrolled. The median age was 44 (range: 22-71) and 78% were female. At enrolment, 72% of participants were seropositive for SARS-CoV-2. 56% of participants were vaccinated with one dose, of whom 98% received their first shot within 4days of enrolment. All HWs received the Pfizer BNT162b2 mRNA COVID-19 vaccine. ETHICS AND DISSEMINATION: The study protocol and procedures were reviewed and approved by the WHO Ethical Review Board, reference number CERC.0097A, and the Albanian Institute of Public Health Ethical Review Board, reference number 156. All participants have provided written informed consent to participate in this study. The primary results of this study will be published in a peer-reviewed journal at the time of completion. TRIAL REGISTRATION NUMBER: NCT04811391. |
Cohort profile: Indian Network of Population-Based Surveillance Platforms for Influenza and Other Respiratory Viruses among the Elderly (INSPIRE).
Krishnan A , Dar L , Amarchand R , Prabhakaran AO , Kumar R , Rajkumar P , Kanungo S , Bhardwaj SD , Choudekar A , Potdar V , Chakrabarti AK , Kumar CG , Parameswaran GG , Dhakad S , Manna B , Choudhary A , Lafond KE , Azziz-Baumgartner E , Saha S . BMJ Open 2021 11 (10) e052473 PURPOSE: We describe here a multicentric community-dwelling cohort of older adults (>60 years of age) established to estimate incidence, study risk factors, healthcare utilisation and economic burden associated with influenza and respiratory syncytial virus (RSV) in India. PARTICIPANTS: The four sites of this cohort are in northern (Ballabgarh), southern (Chennai), eastern (Kolkata) and western (Pune) parts of India. We enrolled 5336 participants across 4220 households and began surveillance in July 2018 for viral respiratory infections with additional participants enrolled annually. Trained field workers collected data about individual-level and household-level risk factors at enrolment and quarterly assessed frailty and grip strength. Trained nurses surveilled weekly to identify acute respiratory infections (ARI) and clinically assessed individuals to diagnose acute lower respiratory infection (ALRI) as per protocol. Nasal and oropharyngeal swabs are collected from all ALRI cases and one-fifth of the other ARI cases for laboratory testing. Cost data of the episode are collected using the WHO approach for estimating the economic burden of seasonal influenza. Handheld tablets with Open Data Kit platform were used for data collection. FINDINGS TO DATE: The attrition of 352 participants due to migration and deaths was offset by enrolling 680 new entrants in the second year. All four sites reported negligible influenza vaccination uptake (0.1%-0.4%), low health insurance coverage (0.4%-22%) and high tobacco use (19%-52%). Ballabgarh had the highest proportion (54.4%) of households in the richest wealth quintile, but reported high solid fuel use (92%). Frailty levels were highest in Kolkata (11.3%) and lowest in Pune (6.8%). The Chennai cohort had highest self-reported morbidity (90.1%). FUTURE PLANS: The findings of this cohort will be used to inform prioritisation of strategies for influenza and RSV control for older adults in India. We also plan to conduct epidemiological studies of SARS-CoV-2 using this platform. |
Estimating the number of averted illnesses and deaths as a result of vaccination against an influenza pandemic in nine low- and middle-income countries
Lutz CS , Biggerstaff M , Rolfes MA , Lafond KE , Azziz-Baumgartner E , Porter RM , Reed C , Bresee JS . Vaccine 2021 39 (30) 4219-4230 BACKGROUND: During the 2009 influenza A(H1N1)pdm09 pandemic, 77 countries received donated monovalent A(H1N1)pdm09 vaccine through the WHO Pandemic Influenza A(H1N1) Vaccine Deployment Initiative. However, 47% did not receive their first shipment until after the first wave of virus circulation, and 8% did not receive their first shipment until after the WHO declared the end of the pandemic. Arguably, these shipments were too late into the pandemic to have a substantial effect on virus transmission or disease burden during the first waves of the pandemic. OBJECTIVES: In order to evaluate the potential benefits of earlier vaccine availability, we estimated the number of illnesses and deaths that could be averted during a 2009-like influenza pandemic under five different vaccine-availability timing scenarios. METHODS: We adapted a model originally developed to estimate annual influenza morbidity and mortality burden averted through US seasonal vaccination and ran it for five vaccine availability timing scenarios in nine low- and middle-income countries that received donated vaccine. RESULTS: Among nine study countries, we estimated that the number of averted cases was 61-216,197 for actual vaccine receipt, increasing to 2,914-283,916 had vaccine been available simultaneously with the United States. CONCLUSIONS: Earlier delivery of vaccines can reduce influenza case counts during a simulated 2009-like pandemic in some low- and middle-income countries. For others, increasing the number of cases and deaths prevented through vaccination may be dependent on factors other than timely initiation of vaccine administration, such as distribution and administration capacity. |
Efficacy of live attenuated and inactivated influenza vaccines among children in rural India: A 2-year, randomized, triple-blind, placebo-controlled trial
Krishnan A , Dar L , Saha S , Narayan VV , Kumar R , Kumar R , Amarchand R , Dhakad S , Chokker R , Choudekar A , Gopal G , Choudhary A , Potdar V , Chadha M , Lafond KE , Lindstrom S , Widdowson MA , Jain S . PLoS Med 2021 18 (4) e1003609 BACKGROUND: Influenza is a cause of febrile acute respiratory infection (FARI) in India; however, few influenza vaccine trials have been conducted in India. We assessed absolute and relative efficacy of live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) among children aged 2 to 10 years in rural India through a randomized, triple-blind, placebo-controlled trial conducted over 2 years. METHODS AND FINDINGS: In June 2015, children were randomly allocated to LAIV, IIV, intranasal placebo, or inactivated polio vaccine (IPV) in a 2:2:1:1 ratio. In June 2016, vaccination was repeated per original allocation. Overall, 3,041 children received LAIV (n = 1,015), IIV (n = 1,010), nasal placebo (n = 507), or IPV (n = 509). Mean age of children was 6.5 years with 20% aged 9 to 10 years. Through weekly home visits, nasal and throat swabs were collected from children with FARI and tested for influenza virus by polymerase chain reaction. The primary outcome was laboratory-confirmed influenza-associated FARI; vaccine efficacy (VE) was calculated using modified intention-to-treat (mITT) analysis by Cox proportional hazards model (PH) for each year. In Year 1, VE was 40.0% (95% confidence interval (CI) 25.2 to 51.9) for LAIV and 59.0% (95% CI 47.8 to 67.9) for IIV compared with controls; relative efficacy of LAIV compared with IIV was -46.2% (95% CI -88.9 to -13.1). In Year 2, VE was 51.9% (95% CI 42.0 to 60.1) for LAIV and 49.9% (95% CI 39.2 to 58.7) for IIV; relative efficacy of LAIV compared with IIV was 4.2% (95% CI -19.9 to 23.5). No serious adverse vaccine-attributable events were reported. Study limitations include differing dosage requirements for children between nasal and injectable vaccines (single dose of LAIV versus 2 doses of IIV) in Year 1 and the fact that immunogenicity studies were not conducted. CONCLUSIONS: In this study, we found that LAIV and IIV vaccines were safe and moderately efficacious against influenza virus infection among Indian children. TRIAL REGISTRATION: Clinical Trials Registry of India CTRI/2015/06/005902. |
Incidence, risk factors, and viral etiology of community-acquired acute lower respiratory tract infection among older adults in rural north India
Kumar R , Dar L , Amarchand R , Saha S , Lafond KE , Purakayastha DR , Kumar R , Choudekar A , Gopal G , Dhakad S , Narayan VV , Wahi A , Chhokar R , Lindstrom S , Whitaker B , Choudhary A , Dey AB , Krishnan A . J Glob Health 2021 11 04027 BACKGROUND: There are limited data on incidence, risk factors and etiology of acute lower respiratory tract infection (LRTI) among older adults in low- and middle-income countries. METHODS: We established a cohort of community dwelling older adults ≥60 years and conducted weekly follow-up for acute respiratory infections (ARI) during 2015-2017. Nurses assessed ARI cases for LRTI, collecting combined nasal/throat swabs from all LRTI cases and an equal number of age- and sex-matched asymptomatic neighbourhood controls. Swabs were tested for influenza viruses, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and parainfluenza viruses (PIV) using polymerase chain reaction. LRTI and virus-specific LRTI incidence was calculated per 1000 person-years. We estimated adjusted incidence rate ratios (IRR) for risk factors using Poisson regression and calculated etiologic fractions (EF) using adjusted odds ratios for detection of viral pathogens in LRTI cases vs controls. RESULTS: We followed 1403 older adults for 2441 person-years. LRTI and LRTI-associated hospitalization incidences were 248.3 (95% confidence interval (CI) = 229.3-268.8) and 12.7 (95% CI = 8.9-18.1) per 1000 person-years. Persons with pre-existing chronic bronchitis as compared to those without (incidence rate ratio (IRR) = 4.7, 95% CI = 3.9-5.6); aged 65-74 years (IRR = 1.6, 95% CI = 1.3-2.0) and ≥75 years (IRR = 1.8, 95% CI = 1.4-2.4) as compared to 60-64 years; and persons in poorest wealth quintile (IRR = 1.4, 95% CI = 1.1-1.8); as compared to those in wealthiest quintile were at higher risk for LRTI. Virus was detected in 10.1% of LRTI cases, most commonly influenza (3.8%) and RSV (3.0%). EF for RSV and influenza virus was 83.9% and 83.6%, respectively. CONCLUSION: In this rural cohort of older adults, the incidence of LRTI was substantial. Chronic bronchitis was an important risk factor; influenza virus and RSV were major viral pathogens. |
Ancillary benefits of seasonal influenza vaccination in middle-income countries.
Ebama MS , Chu SY , Azziz-Baumgartner E , Lafond KE , McCarron M , Hadler SC , Porter RM , McKinlay M , Bresee J . Vaccine 2021 39 (14) 1892-1896 While seasonal influenza vaccines (SIV) remain the best method to prevent influenza-associated illnesses, implementing SIV programs may benefit countries beyond disease reduction, strengthening health systems and national immunization programs, or conversely, introduce new challenges. Few studies have examined perceived impacts of SIV introduction beyond disease reduction on health systems; understanding such impacts will be particularly salient in the context of COVID-19 vaccine introduction. We collected qualitative data from key informants-Partnership for Influenza Vaccine Introduction (PIVI) contacts in six middle-income PIVI vaccine recipient countries-to understand perceptions of ancillary benefits and challenges from SIV implementation. Respondents reported benefits associated with SIV introduction, including improved attitudes to SIV among risk groups (characterized by increased demand) and perceptions that SIV introduction improved relationships with other ministries and collaboration with mass media. Challenges included sustaining investment in SIV programs, as vaccine supply did not always meet coverage goals, and managing SIV campaigns. |
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