Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
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Immunological response to fractional-dose yellow fever vaccine administered during an outbreak in Kinshasa, Democratic Republic of the Congo: results 5 years after vaccination from a prospective cohort study
Doshi RH , Mukadi PK , Casey RM , Kizito GM , Gao H , Nguete UB , Laven J , Sabi L , Kaba DK , Muyembe-Tamfum JJ , Hyde TB , Ahuka-Mundeke S , Staples JE . Lancet Infect Dis 2024 BACKGROUND: In 2016, outbreaks of yellow fever in Angola and the Democratic Republic of the Congo led to a global vaccine shortage. A fractional dose of 17DD yellow fever vaccine (containing one-fifth [0·1 ml] of the standard dose) was used during a pre-emptive mass campaign in August, 2016, in Kinshasa, Democratic Republic of the Congo among children aged 2 years and older and non-pregnant adults (ie, those aged 18 years and older). 1 year following vaccination, 97% of participants were seropositive; however, the long-term durability of the immune response is unknown. We aimed to conduct a prospective cohort study and invited participants enrolled in the previous evaluation to return 5 years after vaccination to assess durability of the immune response. METHODS: Participants returned to one of six health facilities in Kinshasa in 2021, where study staff collected a brief medical history and blood specimen. We assessed neutralising antibody titres against yellow fever virus using a plaque reduction neutralisation test with a 50% cutoff (PRNT(50)). Participants with a PRNT(50) titre of 10 or higher were considered seropositive. The primary outcome was the proportion of participants seropositive at 5 years. FINDINGS: Among the 764 participants enrolled, 566 (74%) completed the 5-year visit. 5 years after vaccination, 539 (95·2%, 95% CI 93·2-96·7) participants were seropositive, including 361 (94·3%, 91·5-96·2) of 383 who were seronegative and 178 (97·3%, 93·8-98·8) of 183 who were seropositive at baseline. Geometric mean titres (GMTs) differed significantly across age groups for those who were initially seronegative with the lowest GMT among those aged 2-5 years and highest among those aged 13 years and older. INTERPRETATION: A fractional dose of the 17DD yellow fever vaccine induced an immunologic response with detectable titres at 5 years among the majority of participants in the Democratic Republic of the Congo. These findings support the use of fractional-dose vaccination for outbreak prevention with the potential for sustained immunity. FUNDING: Gavi, the Vaccine Alliance through the CDC Foundation. TRANSLATION: For the French translation of the abstract see Supplementary Materials section. |
Covid-19 pandemic and equity of global human papillomavirus vaccination: descriptive study of World Health Organization-Unicef vaccination coverage estimates
Casey RM , Akaba H , Hyde TB , Bloem P . BMJ Med 2024 3 (1) e000726 OBJECTIVE: To analyse progress in global vaccination against human papillomavirus (HPV) during the covid-19 pandemic, with a particular focus on equity. DESIGN: Descriptive study of World Health Organization-Unicef vaccination coverage estimates. SETTING: WHO-Unicef estimates of global, regional, and national HPV vaccination coverage, before (2010-19) and during (2020-21) the covid-19 pandemic. PARTICIPANTS: Girls aged 9-14 years who received a HPV vaccine globally before (12.3 million in 2019) and during (2020-21) the covid-19 pandemic (10.6 million in 2021). MAIN OUTCOME MEASURES: Mean programme and population adjusted coverage for first dose HPV vaccine (HPV1) by country, country income (World Bank income categories), sex, and WHO region, before (2010-19) and during (2020-21) the covid-19 pandemic, based on WHO-Unicef estimates of HPV vaccination coverage. Annual number of national HPV vaccine programme introduced since the first HPV vaccine licence was granted in 2006, based on data reported to WHO-Unicef. Number of girls vaccinated before (2019) versus during (2020-21) the covid-19 pandemic period. RESULTS: Mean coverage of HPV vaccination programmes among girls decreased from 65% in 2010-19 to 50% in 2020-21 in low and middle income countries compared with an increase in high income countries from 61% to 69% for the same periods. Population adjusted HPV1 coverage was higher among girls in high income countries before and during the covid-19 pandemic than in girls in low and middle income countries. During the covid-19 pandemic, population adjusted HPV1 coverage among boys in high income countries was higher and remained higher than coverage among girls in low and middle income countries. Globally, 23 countries recorded a severe reduction in their HPV programme (≥50% reduction in coverage), and another 3.8 million girls globally did not receive a HPV vaccine in countries with existing HPV vaccination programmes in 2020-21 compared with 2019. A reduction was seen in the annual rate of new introductions of national HPV vaccine programmes during 2020-21, affecting countries in all income categories, followed by an increase in introductions during 2022. During the second half of 2023, several low and middle income countries with large birth cohorts and a high relative burden of cervical cancer have yet to introduce HPV vaccination. CONCLUSIONS: Although HPV vaccines have been available for more than 15 years, global HPV vaccination coverage is low. During the covid-19 pandemic period (2020-21 globally), worsening coverage, delayed introductions of national vaccine programmes, and an increase in missed girls globally (ie, girls who did not receive a HPV vaccine compared with the previous year in countries with an existing HPV vaccination programme) that disproportionately affected girls in low and middle income countries were found. Urgent and innovative recovery efforts are needed to accelerate national introduction of HPV vaccination programmes and achieve high coverage of HPV vaccination worldwide. |
Supporting evidence-based rotavirus vaccine introduction decision-making and implementation: Lessons from 8 Gavi-eligible countries
Jennings MC , Sauer M , Manchester C , Soeters HM , Shimp L , Hyde TB , Parashar U , Burgess C , Castro B , Hossein I , Othepa M , Payne DC , Tate JE , Walldorf J , Privor-Dumm L , Richart V , Santosham M . Vaccine 2023 42 (1) 8-16 Despite the 2009 World Health Organization recommendation that all countries introduce rotavirus vaccines (RVV) into their national immunization programs, just 81 countries had introduced RVV by the end of 2015, leaving millions of children at risk for rotavirus morbidity and mortality. In response, the Rotavirus Accelerated Vaccine Introduction Network (RAVIN) was established in 2016 to provide support to eight Gavi-eligible countries that had yet to make an RVV introduction decision and/or had requested technical assistance with RVV preparations: Afghanistan, Bangladesh, Benin, Cambodia, Democratic Republic of Congo, Lao People's Democratic Republic, Myanmar, and Nepal. During 2016-2020, RAVIN worked with country governments and partners to support evidence-based immunization decision-making, RVV introduction preparation and implementation, and multilateral coordination. By the September 2020 program close-out, five of the eight RAVIN focus countries successfully introduced RVV into their routine childhood immunization programs. We report on the RAVIN approach, describe how the project responded collectively to an evolving RVV product landscape, synthesize common characteristics of the RAVIN country experiences, highlight key lessons learned, and outline the unfinished agenda to inform future new vaccine introduction efforts by countries and global partners. |
Vaccine value profile for cytomegalovirus
Boppana SB , van Boven M , Britt WJ , Gantt S , Griffiths PD , Grosse SD , Hyde TB , Lanzieri TM , Mussi-Pinhata MM , Pallas SE , Pinninti SG , Rawlinson WD , Ross SA , Vossen Actm , Fowler KB . Vaccine 2023 41 Suppl 2 S53-S75 Cytomegalovirus (CMV) is the most common infectious cause of congenital malformation and a leading cause of developmental disabilities such as sensorineural hearing loss (SNHL), motor and cognitive deficits. The significant disease burden from congenital CMV infection (cCMV) led the US National Institute of Medicine to rank CMV vaccine development as the highest priority. An average of 6.7/1000 live births are affected by cCMV, but the prevalence varies across and within countries. In contrast to other congenital infections such as rubella and toxoplasmosis, the prevalence of cCMV increases with CMV seroprevalence rates in the population. The true global burden of cCMV disease is likely underestimated because most infected infants (85-90 %) have asymptomatic infection and are not identified. However, about 7-11 % of those with asymptomatic infection will develop SNHL throughout early childhood. Although no licensed CMV vaccine exists, several candidate vaccines are in development, including one currently in phase 3 trials. Licensure of one or more vaccine candidates is feasible within the next five years. Various models of CMV vaccine strategies employing different target populations have shown to provide substantial benefit in reducing cCMV. Although CMV can cause end-organ disease with significant morbidity and mortality in immunocompromised individuals, the focus of this vaccine value profile (VVP) is on preventing or reducing the cCMV disease burden. This CMV VVP provides a high-level, comprehensive assessment of the currently available data to inform the potential public health, economic, and societal value of CMV vaccines. The CMV VVP was developed by a working group of subject matter experts from academia, public health groups, policy organizations, and non-profit organizations. All contributors have extensive expertise on various elements of the CMV VVP and have described the state of knowledge and identified the current gaps. The VVP was developed using only existing and publicly available information. |
Ebola vaccine uptake and attitudes among healthcare workers in North Kivu, Democratic Republic of the Congo, 2021
Doshi RH , Garbern SC , Kulkarni S , Perera SM , Fleming MK , Muhayangabo RF , Ombeni AB , Tchoualeu DD , Kallay R , Song E , Powell J , Gainey M , Glenn B , Mutumwa RM , Hans Bateyi Mustafa S , Earle-Richardson G , Gao H , Abad N , Soke GN , Fitter DL , Hyde TB , Prybylski D , Levine AC , Jalloh MF , Mbong EN . Front Public Health 2023 11 1080700 INTRODUCTION: During the 2018-2020 Ebola virus disease (EVD) outbreak in the eastern part of the Democratic Republic of the Congo (DRC), prevention and control measures, such as Ebola vaccination were challenging by community mistrust. We aimed to understand perceptions regarding Ebola vaccination and identify determinants of Ebola vaccine uptake among HCWs. METHODS: In March 2021, we conducted a cross-sectional survey among 438 HCWs from 100 randomly selected health facilities in three health zones (Butembo, Beni, Mabalako) affected by the 10th EVD outbreak in North Kivu, DRC. HCWs were eligible if they were ≥ 18 years and were working in a health facility during the outbreak. We used survey logistic regression to assess correlates of first-offer uptake (i.e., having received the vaccine the first time it was offered vs. after subsequent offers). RESULTS: Of the 438 HCWs enrolled in the study, 420 (95.8%) reported that they were eligible and offered an Ebola vaccine. Among those offered vaccination, self-reported uptake of the Ebola vaccine was 99.0% (95% confidence interval (CI) [98.5-99.4]), but first-offer uptake was 70.2% (95% CI [67.1, 73.5]). Nearly all HCWs (94.3%; 95% CI [92.7-95.5]) perceived themselves to be at risk of contracting EVD. The most common concern was that the vaccine would cause side effects (65.7%; 95% CI [61.4-69.7]). In the multivariable analysis, mistrust of the vaccine source or how the vaccine was produced decreased the odds of first-time uptake. DISCUSSION: Overall uptake of the Ebola vaccine was high among HCWs, but uptake at the first offer was substantially lower, which was associated with mistrust of the vaccine source. Future Ebola vaccination efforts should plan to make repeated vaccination offers to HCWs and address their underlying mistrust in the vaccines, which can, in turn, improve community uptake. |
Status of new vaccine introduction - worldwide, 2016-2021
Kaur G , Casey RM , Patel JC , Bloem P , Walldorf JA , Hyde TB . MMWR Morb Mortal Wkly Rep 2023 72 (27) 746-750 This report describes the status of introductions globally for eight World Health Organization (WHO)-recommended new and underutilized vaccines, comprising 10 individual vaccine antigens. By 2021, among 194 countries worldwide, 33 (17%) provided all of these 10 WHO-recommended antigens as part of their routine immunization schedules; only one low-income country had introduced all of these recommended vaccines. Universal hepatitis B birth dose; human papillomavirus vaccine; rotavirus vaccine; and diphtheria, tetanus, and pertussis-containing vaccine first booster dose have been introduced by 57%, 59%, 60%, and 72% of all countries worldwide, respectively. Pneumococcal conjugate vaccine, rubella-containing vaccine, measles-containing vaccine second dose, and Haemophilus influenzae type b vaccine have been introduced by 78%, 89%, 94%, and 99% of all countries, respectively. The annual rate of new vaccine introductions declined precipitously when the COVID-19 pandemic started, from 48 in 2019 to 15 in 2020 before rising to 26 in 2021. Increased efforts to accelerate new and underutilized vaccine introductions are urgently needed to improve universal equitable access to all recommended vaccines to achieve the global Immunization Agenda 2021-2030 (IA2030) targets. |
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. |
Head-to-head comparison of the immunogenicity of RotaTeq and Rotarix rotavirus vaccines and factors associated with seroresponse in infants in Bangladesh: a randomised, controlled, open-label, parallel, phase 4 trial
Velasquez-Portocarrero DE , Wang X , Cortese MM , Snider CJ , Anand A , Costantini VP , Yunus M , Aziz AB , Haque W , Parashar U , Sisay Z , Soeters HM , Hyde TB , Jiang B , Zaman K . Lancet Infect Dis 2022 22 (11) 1606-1616 BACKGROUND: A head-to-head comparison of the most widely used oral rotavirus vaccines has not previously been done, particularly in a high child mortality setting. We therefore aimed to compare the immunogenicity of RotaTeq (Merck, Kenilworth, NJ, USA) and Rotarix (GlaxoSmithKline, Rixensart, Belgium) rotavirus vaccines in the same population and examined risk factors for low seroresponse. METHODS: We did a randomised, controlled, open-label, parallel, phase 4 trial in urban slums within Mirpur and Mohakahli (Dhaka, Bangladesh). We enrolled eligible participants who were healthy infants aged 6 weeks and full-term (ie, >37 weeks' gestation). We randomly assigned participants (1:1), using block randomisation via a computer-generated electronic allocation with block sizes of 8, 16, 24, and 32, to receive either three RotaTeq vaccine doses at ages 6, 10, and 14 weeks or two Rotarix doses at ages 6 and 10 weeks without oral poliovirus vaccine. Coprimary outcomes were the rotavirus-specific IgA seroconversion in both vaccines, and the comparison of the rotavirus IgA seroconversion by salivary secretor phenotype in each vaccine arm. Seroconversion at age 18 weeks in the RotaTeq arm and age of 14 weeks in the Rotarix arm was used to compare the complete series of each vaccine. Seroconversion at age 14 weeks was used to compare two RotaTeq doses versus two Rotarix doses. Seroconversion at age 22 weeks was used to compare the immunogenicity at the same age after receiving the full vaccine series. Safety was assessed for the duration of study participation. This study is registered with ClinicalTrials.gov, NCT02847026. FINDINGS: Between Sept 1 and Dec 8, 2016, a total of 1144 infants were randomly assigned to either the RotaTeq arm (n=571) or Rotarix arm (n=573); 1080 infants (531 in the RotaTeq arm and 549 in the Rotarix arm) completed the study. Rotavirus IgA seroconversion 4 weeks after the full series occurred in 390 (73%) of 531 infants age 18 weeks in the RotaTeq arm and 354 (64%) of 549 infants age 14 weeks in the Rotarix arm (p=0·01). At age 14 weeks, 4 weeks after two doses, RotaTeq recipients had lower seroconversion than Rotarix recipients (268 [50%] of 531 vs 354 [64%] of 549; p<0·0001). However, at age 22 weeks, RotaTeq recipients had higher seroconversion than Rotarix recipients (394 [74%] of 531 vs 278 [51%] of 549; p<0·0001). Among RotaTeq recipients, seroconversion 4 weeks after the third dose was higher than after the second dose (390 [73%] of 531 vs 268 [50%] of 531; p<0·0001]. In the RotaTeq arm, rotavirus IgA seroconversion was lower in non-secretors than in secretors at ages 14 weeks (p=0·08), 18 weeks (p=0·01), and 22 weeks (p=0·02). Similarly, in the Rotarix arm, rotavirus IgA seroconversion was lower in non-secretors than in secretors at ages 14 weeks (p=0·02) and 22 weeks (p=0·01). 65 (11%) of 571 infants had adverse events in the RotaTeq arm compared with 63 (11%) of 573 infants in the Rotarix arm; no adverse events were attributed to the use of either vaccine. One death due to aspiration occurred in the RotaTeq arm, which was not related to the vaccine. INTERPRETATION: RotaTeq induced a higher magnitude and longer duration of rotavirus IgA response than Rotarix in this high child mortality setting. Additional vaccination strategies should be evaluated to overcome the suboptimal performance of current oral rotavirus vaccines in these settings. FUNDING: US Centers for Disease Control and Prevention. |
Vaccination information, motivations, and barriers in the context of meningococcal serogroup A conjugate vaccine introduction: A qualitative assessment among caregivers in Burkina Faso, 2018
Aksnes BN , Walldorf JA , Nkwenkeu SF , Zoma RL , Mirza I , Tarbangdo F , Fall S , Hien S , Ky C , Kambou L , Diallo AO , Aké FH , Hatcher C , Patel JC , Novak RT , Hyde TB , Medah I , Soeters HM , Jalloh MF . Vaccine 2021 39 (43) 6370-6377 BACKGROUND: In March 2017, Burkina Faso introduced meningococcal serogroup A conjugate vaccine (MACV) into the Expanded Programme on Immunization. MACV is administered to children aged 15-18 months, concomitantly with the second dose of measles-containing vaccine (MCV2). One year after MACV introduction, we assessed the sources and content of immunization information available to caregivers and explored motivations and barriers that influence their decision to seek MACV for their children. METHODS: Twenty-four focus group discussions (FGDs) were conducted with caregivers of children eligible for MACV and MCV2. Data collection occurred in February-March 2018 in four purposively selected districts, each from a separate geographic region; within each district, caregivers were stratified into groups based on whether their children were unvaccinated or vaccinated with MACV. FGDs were recorded and transcribed. Transcripts were coded and analyzed using qualitative content analysis. RESULTS: We identified many different sources and content of information about MACV and MCV2 available to caregivers. Healthcare workers were most commonly cited as the main sources of information; caregivers also received information from other caregivers in the community. Caregivers' motivations to seek MACV for their children were driven by personal awareness, engagements with trusted messengers, and perceived protective benefits of MACV against meningitis. Barriers to MACV and MCV2 uptake were linked to the unavailability of vaccines, immunization personnel not providing doses, knowledge gaps about the 15-18 month visit, practical constraints, past negative experiences, sociocultural influences, and misinformation, including misunderstanding about the need for MCV2. CONCLUSIONS: MACV and MCV2 uptake may be enhanced by addressing vaccination barriers and effectively communicating vaccination information and benefits through trusted messengers such as healthcare workers and other caregivers in the community. Educating healthcare workers to avoid withholding vaccines, likely due to fear of wastage, may help reduce missed opportunities for vaccination. |
Vaccination of contacts of Ebola virus disease survivors to prevent further transmission.
Doshi RH , Fleming M , Mukoka AK , Carter RJ , Hyde TB , Choi M , Nzaji MK , Bateyi SH , Christie A , Nichol ST , Damon IK , Beach M , Musenga EM , Fitter DL . Lancet Glob Health 2020 8 (12) e1455-e1456 On April 10, 2020, just 2 days before the anticipated declaration of the end of the North Kivu and Ituri Ebola virus disease (EVD) outbreak in DR Congo, and 53 days after the last confirmed case of EVD had been reported, a new case was confirmed. Sequencing of patient samples from the case in April and six others that followed indicated that these cases were likely to have come from a reintroduction of the virus from a persistently infected survivor.1 This group of cases marked the second flare-up linked to an EVD survivor during this outbreak. In November, 2019, a relapse case in North Kivu resulted in widespread transmission across multiple health zones, helping to extend the outbreak by at least 3 months. |
Health workers' perceptions and challenges in implementing meningococcal serogroup a conjugate vaccine in the routine childhood immunization schedule in Burkina Faso
Nkwenkeu SF , Jalloh MF , Walldorf JA , Zoma RL , Tarbangdo F , Fall S , Hien S , Combassere R , Ky C , Kambou L , Diallo AO , Krishnaswamy A , Ake FH , Hatcher C , Patel JC , Medah I , Novak RT , Hyde TB , Soeters HM , Mirza I . BMC Public Health 2020 20 (1) 254 BACKGROUND: Meningococcal serogroup A conjugate vaccine (MACV) was introduced in 2017 into the routine childhood immunization schedule (at 15-18 months of age) in Burkina Faso to help reduce meningococcal meningitis burden. MACV was scheduled to be co-administered with the second dose of measles-containing vaccine (MCV2), a vaccine already in the national schedule. One year following the introduction of MACV, an assessment was conducted to qualitatively examine health workers' perceptions of MACV introduction, identify barriers to uptake, and explore opportunities to improve coverage. METHODS: Twelve in-depth interviews were conducted with different cadres of health workers in four purposively selected districts in Burkina Faso. Districts were selected to include urban and rural areas as well as high and low MCV2 coverage areas. Respondents included health workers at the following levels: regional health managers (n = 4), district health managers (n = 4), and frontline healthcare providers (n = 4). All interviews were recorded, transcribed, and thematically analyzed using qualitative content analysis. RESULTS: Four themes emerged around supply and health systems barriers, demand-related barriers, specific challenges related to MACV and MCV2 co-administration, and motivations and efforts to improve vaccination coverage. Supply and health systems barriers included aging cold chain equipment, staff shortages, overworked and poorly trained staff, insufficient supplies and financial resources, and challenges with implementing community outreach activities. Health workers largely viewed MACV introduction as a source of motivation for caregivers to bring their children for the 15- to 18-month visit. However, they also pointed to demand barriers, including cultural practices that sometimes discourage vaccination, misconceptions about vaccines, and religious beliefs. Challenges in co-administering MACV and MCV2 were mainly related to reluctance among health workers to open multi-dose vials unless enough children were present to avoid wastage. CONCLUSIONS: To improve effective administration of vaccines in the second-year of life, adequate operational and programmatic planning, training, communication, and monitoring are necessary. Moreover, clear policy communication is needed to help ensure that health workers do not refrain from opening multi-dose vials for small numbers of children. |
Seasonal influenza vaccination in middle-income countries: Assessment of immunization practices in Belarus, Morocco, and Thailand
Mantel C , Chu SY , Hyde TB , Lambach P . Vaccine 2019 38 (2) 212-219 BACKGROUND: Vaccines for the control of seasonal influenza are recommended by the World Health Organization (WHO) for use in specific risk groups, but their use requires operational considerations that may challenge immunization programs. Several middle-income countries have recently implemented seasonal influenza vaccination. Early program evaluation following vaccine introduction can help ascertain positive lessons learned and areas for improvement. METHODS: An influenza vaccine post-introduction evaluation (IPIE) tool was developed jointly by WHO and the U.S. Centers for Disease Control and Prevention to provide a systematic approach to assess influenza vaccine implementation processes. The tool was used in 2017 in three middle-income countries: Belarus, Morocco and Thailand. RESULTS: Data from the three countries highlighted a number of critical factors: Health workers (HWs) are a key target group, given their roles as key influencers of acceptance by other groups, and for ensuring vaccine delivery and improved coverage. Despite WHO recommendations, pregnant women were not always prioritized and may present unique challenges for acceptance. Target group denominators need to be better defined, and vaccine coverage should be validated with vaccine distribution data, including from the private sector. There is a need for strengthening adverse events reporting and for addressing potential vaccine hesitancy through the establishment of risk communication plans. The assessments led to improvements in the countries' influenza vaccination programs, including a revision of policies, changes in vaccine management and coverage estimation, enhanced strategies for educating HWs and intensified collaboration between departments involved in implementing seasonal influenza vaccination. CONCLUSION: The IPIE tool was found useful for delineating operational strengths and weaknesses of seasonal influenza vaccination programs. HWs emerged as a critical target group to be addressed in follow-up action. Findings from this study can help direct influenza vaccination programs in other countries, as well as contribute to pandemic preparedness efforts. The updated IPIE tool is available on the WHO website http://www.who.int/immunization/research/development/influenza/en/index1.html. |
Evaluation of the impact of meningococcal serogroup A conjugate vaccine introduction on second-year-of-life vaccination coverage in Burkina Faso
Zoma RL , Walldorf JA , Tarbangdo F , Patel JC , Diallo AO , Nkwenkeu SF , Kambou L , Nikiema M , Ouedraogo A , Bationo AB , Ouili R , Badolo H , Sawadogo G , Krishnaswamy A , Hatcher C , Hyde TB , Ake F , Novak RT , Wannemuehler K , Mirza I , Medah I , Soeters HM . J Infect Dis 2019 220 S233-s243 BACKGROUND: After successful meningococcal serogroup A conjugate vaccine (MACV) campaigns since 2010, Burkina Faso introduced MACV in March 2017 into the routine Expanded Programme for Immunization schedule at age 15-18 months, concomitantly with second-dose measles-containing vaccine (MCV2). We examined MCV2 coverage in pre- and post-MACV introduction cohorts to describe observed changes regionally and nationally. METHODS: A nationwide household cluster survey of children 18-41 months of age was conducted 1 year after MACV introduction. Coverage was assessed by verification of vaccination cards or recall. Two age groups were included to compare MCV2 coverage pre-MACV introduction (30-41 months) versus post-MACV introduction (18-26 months). RESULTS: In total, 15 925 households were surveyed; 7796 children were enrolled, including 3684 30-41 months of age and 3091 18-26 months of age. Vaccination documentation was observed for 86% of children. The MACV routine coverage was 58% (95% confidence interval [CI], 56%-61%) with variation by region (41%-76%). The MCV2 coverage was 62% (95% CI, 59%-65%) pre-MACV introduction and 67% (95% CI, 64%-69%) post-MACV introduction, an increase of 4.5% (95% CI, 1.3%-7.7%). Among children who received routine MACV and MCV2, 93% (95% CI, 91%-94%) received both at the same visit. Lack of caregiver awareness about the 15- to 18-month visit and vaccine unavailability were common reported barriers to vaccination. CONCLUSIONS: A small yet significant increase in national MCV2 coverage was observed 1 year post-MACV introduction. The MACV/MCV2 coadministration was common. Findings will help inform strategies to strengthen second-year-of-life immunization coverage, including to address the communication and vaccine availability barriers identified. |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - final report
Casey RM , Harris JB , Ahuka-Mundeke S , Dixon MG , Kizito GM , Nsele PM , Umutesi G , Laven J , Kosoy O , Paluku G , Gueye AS , Hyde TB , Ewetola R , Sheria GKM , Muyembe-Tamfum JJ , Staples JE . N Engl J Med 2019 381 (5) 444-454 BACKGROUND: In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. METHODS: We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and at 1 month and 1 year after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. RESULTS: Among 716 participants who completed the 1-month follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Among 684 participants who completed the 1-year follow-up, 666 (97%; 95% CI, 96 to 98) were seropositive for yellow fever antibody. The distribution of titers among the participants who were seronegative for yellow fever antibody at baseline varied significantly among age groups at 1 month and at 1 year (P<0.001 for both comparisons). CONCLUSIONS: A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in participants who were seronegative at baseline. Titers remained above the threshold for seropositivity at 1 year after vaccination in nearly all participants who were seropositive at 1 month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
Differences between coverage of yellow fever vaccine and the first dose of measles-containing vaccine: A desk review of global data sources
Adrien N , Hyde TB , Gacic-Dobo M , Hombach J , Krishnaswamy A , Lambach P . Vaccine 2019 37 (32) 4511-4517 INTRODUCTION: The strategy to Eliminate Yellow Fever Epidemics (EYE) is a global initiative that includes all countries with risk of yellow fever (YF) virus transmission. Of these, 40 countries (27 in Africa and 13 in the Americas) are considered high-risk and targeted for interventions to increase coverage of YF vaccine. Even though the World Health Organization (WHO) recommends that YF vaccine be given concurrently with the first dose of measles-containing vaccine (MCV1) in YF-endemic settings, estimated coverage for MCV1 and YF vaccine have varied widely. The objective of this study was to review global data sources to assess discrepancies in YF vaccine and MCV1 coverage and identify plausible reasons for these discrepancies. METHODS: We conducted a desk review of data from 34 countries (22 in Africa, 12 in Latin America), from 2006 to 2016, with national introduction of YF vaccine and listed as high-risk by the EYE strategy. Data reviewed included procured and administered doses, immunization schedules, routine coverage estimates and reported vaccine stock-outs. In the 30 countries included in the comparitive analysis, differences greater than 3 percentage points between YF vaccine and MCV1 coverage were considered meaningful. RESULTS: In America, there were meaningful differences (7-45%) in coverage of the two vaccines in 6 (67%) of the 9 countries. In Africa, there were meaningful differences (4-27%) in coverage of the two vaccines in 9 (43%) of the 21 countries. Nine countries (26%) reported MVC1 stock-outs while sixteen countries (47%) reported YF vaccine stock-outs for three or more years during 2006-2016. CONCLUSION: In countries reporting significant differences in coverage of the two vaccines, differences may be driven by different target populations and vaccine availability. However,these were not sufficient to completely explain observed differences. Further follow-up is needed to identify possible reasons for differences in coverage rates in several countries where these could not fully be explained. |
Impact of 13-Valent Pneumococcal Conjugate Vaccine on Colonisation and Invasive Disease in Cambodian Children
Turner P , Leab P , Ly S , Sao S , Miliya T , Heffelfinger JD , Batmunkh N , Lessa FC , Walldorf JA , Hyde TB , Ork V , Hossain MS , Gould KA , Hinds J , Cooper BS , Ngoun C , Turner C , Day NPJ . Clin Infect Dis 2019 70 (8) 1580-1588 BACKGROUND: Cambodia introduced the 13-valent pneumococcal conjugate vaccine (PCV13) in January 2015 using a 3+0 dosing schedule and no catch-up campaign. We investigated the effects of this introduction on pneumococcal colonisation and invasive disease in children aged <5 years. METHODS: Six colonisation surveys were done between January 2014 and January 2018 in children attending the outpatient department of a non-governmental paediatric hospital in Siem Reap. Nasopharyngeal swabs were analysed by phenotypic and genotypic methods to detect pneumococcal serotypes and antimicrobial resistance. Invasive pneumococcal disease (IPD) data for January 2012 - December 2018 were retrieved from hospital databases. Pre-PCV IPD data and pre-/post-PCV colonisation data were modelled to estimate vaccine effectiveness (VE). RESULTS: Comparing 2014 with 2016-2018, and using adjusted prevalence ratios, vaccine effectiveness (VE) estimates for colonisation were 16.6% (95% CI 10.6-21.8) for all pneumococci and 39.2% (26.7-46.1) for vaccine serotype (VT) pneumococci. There was a 26.0% (17.7-33.0) decrease in multi-drug resistant pneumococcal colonisation. IPD incidence was estimated to have declined by 26.4% (14.4-35.8) by 2018, with a decrease of 36.3% (23.8-46.9) for VT IPD and an increase of 101.4% (62.0-145.4) for non-vaccine serotype IPD. CONCLUSIONS: Following PCV13 introduction into the Cambodian immunisation schedule there have been declines in VT pneumococcal colonisation and disease in children aged <5 years. Modelling of dominant serotype colonisation data produced plausible vaccine effectiveness estimates. |
Introduction of inactivated poliovirus vaccine in the Philippines: Effect on health care provider and infant caregiver attitudes and practices
Lopez AL , Harris JB , Raguindin PF , Aldaba J , Morales M , Sylim P , Wannemuehler K , Wallace A , Ehlman DC , Hyde TB , Fox KK , Nyambat B , Ducusin MJ , Hampton LM . Vaccine 2018 36 (48) 7399-7407 Background: The introduction of inactivated poliovirus vaccine (IPV) to the Philippines’ national immunization schedule meant the addition of a third injectable vaccine at a child's 14-week immunization visit. Although previous studies have shown that providing multiple vaccines at the same time affected neither the risk of severe adverse events nor vaccine efficacy, concerns were raised that providing three injections at a single visit, with two injections in one leg, might be unacceptable to health care providers (HCP) and infant caregivers. Methods: We conducted pre- and post-IPV introduction surveys on the acceptance and acceptability of the additional injectable vaccine in three of the Philippines’ 17 administrative regions. Regions 3 and 6 were included in the pre-introduction phase and Regions 3, 6 and 10 were included in the post-introduction phase. Thirty public health centers (PHCs) were randomly sampled from each region. HCPs and infant caregivers were interviewed. In addition, vaccination records from a minimum of 20 eligible children pre-introduction and 10 children post-introduction per PHC were reviewed. Results and discussion: We interviewed 89 HCPs and 286 infant caregivers during the pre-introduction phase and 137 HCPs and 455 caregivers during the post-introduction phase. Among 986 vaccination records reviewed post-introduction, 84% (n = 826) of children received all three recommended injections at one visit, with a range from 61% (209/342) in Region 10 to 100% (328/328) in Region 3. The proportion of HCPs reporting that they had administered three or more injectable vaccines and the proportion of caregivers that would be comfortable with their child receiving three or more injectable vaccines at one visit increased from pre- to post-introduction (p < 0.0001 for both). Eighty-seven percent of HCPs that had administered three or more injectable vaccines post-introduction reported being comfortable or very comfortable with the number of vaccines they had administered. |
Descriptive assessment of rabies post-exposure prophylaxis procurement, distribution, monitoring, and reporting in four Asian countries: Bangladesh, Bhutan, Cambodia, and Sri Lanka, 2017-2018
Li AJ , Sreenivasan N , Siddiqi UR , Tahmina S , Penjor K , Sovann L , Gunesekera A , Blanton JD , Knopf L , Hyde TB . Vaccine 2018 37 Suppl 1 A14-A19 BACKGROUND: There are approximately 35,000 human deaths from rabies in Asia annually. Rabies can be prevented through timely post-exposure prophylaxis (PEP) consisting of wound washing, rabies vaccine, and in some cases, rabies immunoglobulin (RIG). However, access to rabies PEP often remains limited to urban areas and is cost-prohibitive. There is little information on procurement, distribution, monitoring, and reporting of rabies PEP. METHODS: We interviewed key informants in the public sector from various levels in Bangladesh, Bhutan, Cambodia, and Sri Lanka between March 2017 and May 2018 using a descriptive assessment tool to obtain information on procurement, distribution, monitoring, and reporting of rabies PEP. These four countries in Asia were chosen to showcase a range of rabies PEP systems. National rabies focal points were interviewed in each country and focal points helped identify additional key informants at lower levels. RESULTS: A total of 22 key informants were interviewed at various levels (central level to health facility level) including national rabies focal points in each country. Each country has a unique system for managing rabies PEP procurement, distribution, monitoring, and reporting. There are varying levels of PEP access for those with potential rabies exposures. Rabies PEP is available in select health facilities throughout the country in Bangladesh, Bhutan, and Sri Lanka. In Cambodia, rabies PEP is limited to two urban centers. The availability of RIG in all four countries is limited. In these four countries, most aspects of the rabies PEP distribution system operate independently of systems for other vaccines. However, in Bhutan, rabies PEP and Expanded Programme on Immunization (EPI) vaccines share cold chain space in some locations at the lowest level. All countries have a monitoring system in place, but there is limited reporting of data, particularly to the central level. CONCLUSION: Systems to procure, deliver, monitor, and report on rabies PEP are variable across countries. Sharing information on practices more widely among countries can help programs to increase access to this life-saving treatment. |
Cluster anxiety-related adverse events following immunization (AEFI): An assessment of reports detected in social media and those identified using an online search engine
Suragh TA , Lamprianou S , MacDonald NE , Loharikar AR , Balakrishnan MR , Benes O , Hyde TB , McNeil MM . Vaccine 2018 36 (40) 5949-5954 BACKGROUND: Adverse events following immunization (AEFI) arising from anxiety have rarely been reported as a cluster(s) in the setting of a mass vaccination program. Reports of clusters of anxiety-related AEFIs are understudied. Social media and the web may be a resource for public health investigators. METHODS: We searched Google and Facebook separately from Atlanta and Geneva to identify reports of cluster anxiety-related AEFIs. We reviewed a sample of reports summarizing year, country/setting, vaccine involved, patient symptoms, clinical management, and impact to vaccination programs. RESULTS: We found 39 reports referring to 18 unique cluster events. Some reports were only found based on the geographic location from where the search was performed. The most common vaccine implicated in reports was human papillomavirus (HPV) vaccine (48.7%). The majority of reports (97.4%) involved children and vaccination programs in school settings or as part of national vaccination campaigns. Five vaccination programs were reportedly halted because of these cluster events. In this study, we identified 18 cluster events that were not published in traditional scientific peer-reviewed literature. CONCLUSIONS: Social media and online search engines are useful resources for identifying reports of cluster anxiety-related AEFIs and the geographic location of the researcher is an important factor to consider when conducting these studies. Solely relying upon traditional peer-reviewed journals may seriously underestimate the occurrence of such cluster events. |
Immunogenicity of fractional-dose vaccine during a yellow fever outbreak - preliminary report
Ahuka-Mundeke S , Casey RM , Harris JB , Dixon MG , Nsele PM , Kizito GM , Umutesi G , Laven J , Paluku G , Gueye AS , Hyde TB , Sheria GKM , Muyembe-Tanfum JJ , Staples JE . N Engl J Med 2018 381 (5) 444-454 Background In 2016, the response to a yellow fever outbreak in Angola and the Democratic Republic of Congo led to a global shortage of yellow fever vaccine. As a result, a fractional dose of the 17DD yellow fever vaccine (containing one fifth [0.1 ml] of the standard dose) was offered to 7.6 million children 2 years of age or older and nonpregnant adults in a preemptive campaign in Kinshasa. The goal of this study was to assess the immune response to the fractional dose in a large-scale campaign. Methods We recruited participants in four age strata at six vaccination sites. We assessed neutralizing antibody titers against yellow fever virus in blood samples obtained before vaccination and 28 to 35 days after vaccination, using a plaque reduction neutralization test with a 50% cutoff (PRNT50). Participants with a PRNT50 titer of 10 or higher at baseline were considered to be seropositive. Those with a baseline titer of less than 10 who became seropositive at follow-up were classified as having undergone seroconversion. Participants who were seropositive at baseline and who had an increase in the titer by a factor of 4 or more at follow-up were classified as having an immune response. Results Among 716 participants who completed follow-up, 705 (98%; 95% confidence interval [CI], 97 to 99) were seropositive after vaccination. Among 493 participants who were seronegative at baseline, 482 (98%; 95% CI, 96 to 99) underwent seroconversion. Among 223 participants who were seropositive at baseline, 148 (66%; 95% CI, 60 to 72) had an immune response. Lower baseline titers were associated with a higher probability of having an immune response (P<0.001). Conclusions A fractional dose of the 17DD yellow fever vaccine was effective at inducing seroconversion in most of the participants who were seronegative at baseline. These findings support the use of fractional-dose vaccination for outbreak control. (Funded by the U.S. Agency for International Development and the Centers for Disease Control and Prevention.). |
CDC activities for improving implementation of human papillomavirus vaccination, cervical cancer screening, and surveillance worldwide
Senkomago V , Duran D , Loharikar A , Hyde TB , Markowitz LE , Unger ER , Saraiya M . Emerg Infect Dis 2017 23 (13) S101-7 Cervical cancer incidence and mortality rates are high, particularly in developing countries. Most cervical cancers can be prevented by human papillomavirus (HPV) vaccination, screening, and timely treatment. The US Centers for Disease Control and Prevention (CDC) provides global technical assistance for implementation and evaluation of HPV vaccination pilot projects and programs and laboratory-related HPV activities to assess HPV vaccines. CDC collaborates with global partners to develop global cervical cancer screening recommendations and manuals, implement screening, create standardized evaluation tools, and provide expertise to monitor outcomes. CDC also trains epidemiologists in cancer prevention through its Field Epidemiology Training Program and is working to improve cancer surveillance by supporting efforts of the World Health Organization in developing cancer registry hubs and assisting countries in estimating costs for developing population-based cancer registries. These activities contribute to the Global Health Security Agenda action packages to improve immunization, surveillance, and the public health workforce globally. |
Lessons learned from emergency response vaccination efforts for cholera, typhoid, yellow fever, and Ebola
Walldorf JA , Date KA , Sreenivasan N , Harris JB , Hyde TB . Emerg Infect Dis 2017 23 (13) S210-6 Countries must be prepared to respond to public health threats associated with emergencies, such as natural disasters, sociopolitical conflicts, or uncontrolled disease outbreaks. Rapid vaccination of populations vulnerable to epidemic-prone vaccine-preventable diseases is a major component of emergency response. Emergency vaccination planning presents challenges, including how to predict resource needs, expand vaccine availability during global shortages, and address regulatory barriers to deliver new products. The US Centers for Disease Control and Prevention supports countries to plan, implement, and evaluate emergency vaccination response. We describe work of the Centers for Disease Control and Prevention in collaboration with global partners to support emergency vaccination against cholera, typhoid, yellow fever, and Ebola, diseases for which a new vaccine or vaccine formulation has played a major role in response. Lessons learned will help countries prepare for future emergencies. Integration of vaccination with emergency response augments global health security through reducing disease burden, saving lives, and preventing spread across international borders. |
Report on WHO meeting on immunization in older adults: Geneva, Switzerland, 22-23 March 2017
Teresa Aguado M , Barratt J , Beard JR , Blomberg BB , Chen WH , Hickling J , Hyde TB , Jit M , Jones R , Poland GA , Friede M , Ortiz JR . Vaccine 2018 36 (7) 921-931 Many industrialized countries have implemented routine immunization policies for older adults, but similar strategies have not been widely implemented in low- and middle-income countries (LMICs). In March 2017, the World Health Organization (WHO) convened a meeting to identify policies and activities to promote access to vaccination of older adults, specifically in LMICs. Participants included academic and industry researchers, funders, civil society organizations, implementers of global health interventions, and stakeholders from developing countries with adult immunization needs. These experts reviewed vaccine performance in older adults, the anticipated impact of adult vaccination programs, and the challenges and opportunities of building or strengthening an adult and older adult immunization platforms. Key conclusions of the meeting were that there is a need for discussion of new opportunities for vaccination of all adults as well as for vaccination of older adults, as reflected in the recent shift by WHO to a life-course approach to immunization; that immunization in adults should be viewed in the context of a much broader model based on an individual's abilities rather than chronological age; and that immunization beyond infancy is a global priority that can be successfully integrated with other interventions to promote healthy ageing. As WHO is looking ahead to a global Decade of Healthy Ageing starting in 2020, it will seek to define a roadmap for interdisciplinary collaborations to integrate immunization with improving access to preventive and other healthcare interventions for adults worldwide. |
Anxiety-related adverse events following immunization (AEFI): A systematic review of published clusters of illness
Loharikar A , Suragh TA , MacDonald NE , Balakrishnan MR , Benes O , Lamprianou S , Hyde TB , McNeil MM . Vaccine 2017 36 (2) 299-305 BACKGROUND: Clusters of anxiety-related adverse events following immunization (AEFI) have been observed in several countries and have disrupted country immunization programs. We conducted a systematic literature review to characterize these clusters, to generate prevention and management guidance for countries. METHODS: We searched seven peer-reviewed databases for English language reports of anxiety-related AEFI clusters (≥2 persons) with pre-specified keywords across 4 categories: symptom term, cluster term, vaccine term, and cluster AEFI phenomenon term/phrase. All relevant reports were included regardless of publication date, case-patient age, or vaccine. Two investigators independently reviewed abstracts and identified articles for full review. Data on epidemiologic/clinical information were extracted from full text review including setting, vaccine implicated, predominant case-patient symptoms, clinical management, community and media response, and outcome/impact on the vaccination program. RESULTS: Of 1472 abstracts reviewed, we identified eight published clusters, from all six World Health Organization (WHO) regions except the African Region. Seven clusters occurred among children in school settings, and one was among adult military reservists. The size and nature of these clusters ranged from 7 patients in one school to 806 patients in multiple schools. Patients' symptoms included dizziness, headache, and fainting with rapid onset after vaccination. Implicated vaccines included tetanus (2), tetanus-diphtheria (1), hepatitis B (1), oral cholera (1), human papillomavirus (1), and influenza A (H1N1)pdm09 (2). In each report, all affected individuals recovered rapidly; however, vaccination program disruption was noted in some instances, sometimes for up to one year. CONCLUSIONS: Anxiety-related AEFI clusters can be disruptive to vaccination programs, reducing public trust in immunizations and impacting vaccination coverage; response efforts to restore public confidence can be resource intensive. Health care providers should have training on recognition and clinical management of anxiety-related AEFI; public health authorities should have plans to prevent and effectively manage anxiety-related AEFI clusters. Prompt management of these occurrences can be even more important in an era of social media, in which information is rapidly spread. |
Expansion of vaccination services and strengthening vaccine-preventable diseases surveillance in Haiti, 2010-2016
Tohme RA , Francois J , Cavallaro KF , Paluku G , Yalcouye I , Jackson E , Wright T , Adrien P , Katz MA , Hyde TB , Faye P , Kimanuka F , Dietz V , Vertefeuille J , Lowrance D , Dahl B , Patel R . Am J Trop Med Hyg 2017 97 28-36 Following the 2010 earthquake, Haiti was at heightened risk for vaccine-preventable diseases (VPDs) outbreaks due to the exacerbation of long-standing gaps in the vaccination program and subsequent risk of VPD importation from other countries. Therefore, partners supported the Haitian Ministry of Health and Population to improve vaccination services and VPD surveillance. During 2010-2016, three polio, measles, and rubella vaccination campaigns were implemented, achieving a coverage > 90% among children and maintaining Haiti free of those VPDs. Furthermore, Haiti is on course to eliminate maternal and neonatal tetanus, with 70% of communes achieving tetanus vaccine two-dose coverage > 80% among women of childbearing age. In addition, the vaccine cold chain storage capacity increased by 91% at the central level and 285% at the department level, enabling the introduction of three new vaccines (pentavalent, rotavirus, and pneumococcal conjugate vaccines) that could prevent an estimated 5,227 deaths annually. Haiti moved from the fourth worst performing country in the Americas in 2012 to the sixth best performing country in 2015 for adequate investigation of suspected measles/rubella cases. Sentinel surveillance sites for rotavirus diarrhea and meningococcal meningitis were established to estimate baseline rates of those diseases prior to vaccine introduction and to evaluate the impact of vaccination in the future. In conclusion, Haiti significantly improved vaccination services and VPD surveillance. However, high dependence on external funding and competing vaccination program priorities are potential threats to sustaining the improvements achieved thus far. Political commitment and favorable economic and legal environments are needed to maintain these gains. |
Considerations for use of Ebola vaccine during an emergency response
Walldorf JA , Cloessner EA , Hyde TB , MacNeil A . Vaccine 2017 37 (48) 7190-7200 Vaccination against Ebola virus disease is a tool that may limit disease transmission and deaths in future outbreaks, integrated within traditional Ebola outbreak prevention and control measures. Although a licensed Ebolavirus vaccine (EV) is not yet available, the 2014-2016 West African Ebola outbreak has accelerated EV clinical trials and given public health authorities in Guinea, Liberia, and Sierra Leone experience with implementation of emergency ring vaccination. As evidence supporting the use of EV during an outbreak response has become available, public health authorities in at-risk countries are considering how to integrate EV into future emergency Ebola responses and for prevention in high-risk groups, such as healthcare workers and frontline workers (HCW/FLWs), even before an EV is licensed. This review provides an overview of Ebola epidemiology, immunology, and evidence to inform regional and country-level decisions regarding EV delivery during an emergency response and to at-risk populations before a licensed vaccine is available and beyond. Countries or regions planning to use EV will need to assess factors such as the likelihood of a future Ebolavirus outbreak, the most likely species to cause an outbreak, the availability of a safe and effective EV (unlicensed or licensed) for the affected population, capacity to implement Ebola vaccination in conjunction with standard Ebola outbreak control measures, and availability of minimum essential resources and regulatory requirements to implement emergency Ebola vaccination. Potential emergency vaccination strategies for consideration include ring or geographically targeted community vaccination, HCW/FLW vaccination, and mass vaccination. The development of guidelines and protocols for Ebola vaccination will help ensure that activities are standardized, evidence-based, and well-coordinated with overall Ebola outbreak response efforts in the future. |
Acceptance of the administration of multiple injectable vaccines in a single immunization visit in Albania
Preza I , Subaiya S , Harris JB , Ehlman DC , Wannemuehler K , Wallace AS , Huseynov S , Hyde TB , Nelaj E , Bino S , Hampton LM . J Infect Dis 2017 216 S146-S151 Background. Albania introduced inactivated polio vaccine (IPV) into its immunization system in May 2014, increasing the maximum recommended number of injectable vaccines given in a single visit from 2 to 3. Methods. Health-care providers and caregivers were interviewed at 42 health facilities in Albania to assess knowledge, attitudes, and practices regarding injectable vaccine administration. Immunization register data were abstracted from December 2014 to July 2015 at the same facilities to explore the number of injectable vaccines children received during their 2- and 4-month visits. Results. The majority of children (87%) identified in the record review at either their 2- or 4-month immunization visit received all 3 injectable vaccines in a single visit. Almost all children who did not receive the vaccines in a single visit were subsequently fully immunized, most within a 2-week period. Over half of caregivers whose children got 3 or more injectable vaccines in a single visit reported being only comfortable with 1 or 2 injectable vaccines in a single visit. Conclusions. Despite most caregivers expressing hesitation regarding children receiving multiple injectable vaccines in a single visit, most children received vaccines according to the recommended schedule. Almost all children eventually received all recommended vaccines. |
Administering multiple injectable vaccines during a single visit - summary of findings from the accelerated introduction of inactivated polio vaccine globally
Dolan SB , Patel M , Hampton LM , Burnett E , Ehlman DC , Garon J , Cloessner E , Chmielewski E , Hyde TB , Mantel C , Wallace AS . J Infect Dis 2017 216 S152-S160 Background. In 2013, the World Health Organization's (WHO's) Strategic Advisory Group of Experts (SAGE) recommended that all 126 countries using only oral polio vaccine (OPV) introduce at least 1 dose of inactivated polio vaccine (IPV) into their routine immunization schedules by the end of 2015. In many countries, the addition of IPV would necessitate delivery of multiple injectable vaccines (hereafter, "multiple injections") during a single visit, with infants receiving IPV alongside pentavalent vaccine (which covers diphtheria, tetanus, and whole-cell pertussis; hepatitis B; and Haemophilus influenzae type b) and pneumococcal vaccine. Unanticipated concerns emerged from countries over acceptability of multiple injections, sites of administration, and safety. We contextualized the issues surrounding multiple injections by documenting concerns associated with administration of >=3 injections, existing evidence in the published literature, and findings of a systematic review on administration practices and techniques. Methods. Concerns associated with multiple-injection visits were documented from meetings and personal communications with immunization program managers. Published literature on the acceptability of multiple injections by providers and caregivers was summarized, and a systematic review of the literature on administration practices was completed on the following topics: spacing between injection sites (ie, vaccine spacing), site of injection, route of injection, and procedural preparedness. WHO and United Nations Children's Fund data from 2013-2015 were used to assess multiple-injection visits included in national immunization schedules. Results. Healthcare provider and caregiver attitudes and practices indicated concerns about infant pain, potential adverse effects, and uncertainty about vaccine effectiveness with multiple-injection visits. Published literature reinforced the record of safety and acceptance of the recommended schedule of IPV by the SAGE, but the evidence was largely from developed countries. Parental acceptance of multiple injections was associated with a positive provider recommendation to the caregiver. Findings of the systematic review identified that the intramuscular route is preferred over the subcutaneous route for vaccine administration and that the vastus lateralis muscle is preferred over the deltoid muscle for intramuscular injections. Recommendations on vaccine spacing and procedural preparedness were based on practical necessities, but comparative evidence was not identified. During 2013-2015, 85 countries added IPV to their immunization schedules, 46 (55%) of which adopted a schedule resulting in 3 injectable vaccines being administered in a single visit. Conclusion. The multiple-injection experience identified gaps in guidance for future vaccine introductions. Global partner organizations quickly mobilized to assess, document, and communicate the existing global experience on multiple-injection visits. This evidence-based approach provided reassurance to opinion leaders, health workers, and professional societies, thus encouraging uptake of IPV as a second or third injection in an accelerated manner globally. |
Japanese encephalitis surveillance and immunization - Asia and Western Pacific Regions, 2016
Heffelfinger JD , Li X , Batmunkh N , Grabovac V , Diorditsa S , Liyanage JB , Pattamadilok S , Bahl S , Vannice KS , Hyde TB , Chu SY , Fox KK , Hills SL , Marfin AA . MMWR Morb Mortal Wkly Rep 2017 66 (22) 579-583 Japanese encephalitis (JE) virus is the most important vaccine-preventable cause of encephalitis in the Asia-Pacific region. The World Health Organization (WHO) recommends integration of JE vaccination into national immunization schedules in all areas where the disease is a public health priority (1). This report updates a previous summary of JE surveillance and immunization programs in Asia and the Western Pacific in 2012 (2). Since 2012, funding for JE immunization has become available through the GAVI Alliance, three JE vaccines have been WHO-prequalified,* and an updated WHO JE vaccine position paper providing guidance on JE vaccines and vaccination strategies has been published (1). Data for this report were obtained from a survey of JE surveillance and immunization practices administered to health officials in countries with JE virus transmission risk, the 2015 WHO/United Nations Children's Fund Joint Reporting Form on Immunization, notes and reports from JE meetings held during 2014-2016, published literature, and websites. In 2016, 22 (92%) of 24 countries with JE virus transmission risk conducted JE surveillance, an increase from 18 (75%) countries in 2012, and 12 (50%) countries had a JE immunization program, compared with 11 (46%) countries in 2012. Strengthened JE surveillance, continued commitment, and adequate resources for JE vaccination should help maintain progress toward prevention and control of JE. |
Evaluation of knowledge and practices regarding cholera, water treatment, hygiene, and sanitation before and after an oral cholera vaccination campaign-Haiti, 2013-2014
Childs L , Francois J , Choudhury A , Wannemuehler K , Dismer A , Hyde TB , Yen CY , Date KA , Juin S , Katz MA , Kantor EF , Routh J , Etheart M , Wright T , Adrien P , Tohme RA . Am J Trop Med Hyg 2016 95 (6) 1305-1313 In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P < 0.001) and covering (96% versus 89%, P = 0.02) their drinking water. Compared with precampaign, postcampaign survey household observations showed increased availability of soap (16.2% versus 34.5%, P = 0.001) and handwashing stations (14.7% versus 30.1%, P = 0.01), but no significant changes in handwashing practices were reported. Although there was no change in knowledge, significant decreases in water treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control. |
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