Impact of Introducing Hepatitis B Birth Dose Vaccines into the Infant Immunization Program in Burkina Faso: Study Protocol for a Stepped Wedge Cluster Randomized Trial (NéoVac Study).

To achieve global hepatitis elimination by 2030, it is critical to prevent the mother-to-child transmission (MTCT) of hepatitis B virus (HBV). Since 2009, the WHO has recommended administering hepatitis B vaccine to all neonates within 24 h of birth to prevent MTCT. However, many countries in sub-Saharan Africa only provide hepatitis B immunization at the age of 6, 10, and 14 weeks or 8, 12, and 16 weeks using a combined vaccine. To accelerate the introduction of the hepatitis B birth dose vaccine (HepB-BD) into sub-Saharan Africa, it is critical to establish to what extent the addition of HepB-BD can further reduce HBV transmission in areas where three-dose infant vaccination has been implemented. We therefore designed a study to evaluate the impact, acceptability, and cost-effectiveness of incorporating the HepB-BD into the routine immunization program in a real-life field condition in Burkina Faso, where the hepatitis B vaccination is currently scheduled at 8-12-16 weeks. Through a multidisciplinary approach combining epidemiology, anthropology, and health economics, the Neonatal Vaccination against Hepatitis B in Africa (NéoVac) study conducts a pragmatic stepped wedge cluster randomized controlled trial in rural areas of the Hauts-Bassins Region. The study was registered in ClinicalTrials.gov (identifier: NCT04029454). A health center is designated as a cluster, and the introduction of HepB-BD will be rolled out sequentially in 24 centers. Following an initial period in which no health center administers HepB-BD, one center will be randomly allocated to incorporate HepB-BD. Then, at a regular interval, another center will be randomized to cross from the control to the intervention period, until all 24 centers integrate HepB-BD. Pregnant women attending antenatal care will be systematically invited to participate. Infants born during the control period will follow the conventional immunization schedule (8-12-16 weeks), while those born in the interventional period will receive HepB-BD in addition to the routine vaccines (0-8-12-16 weeks). The primary outcome, the proportion of hepatitis B surface antigen (HBsAg) positivity in infants aged at 9 months, will be compared between children born before and after HepB-BD introduction. The study will generate data that may assist governments and stakeholders in sub-Saharan Africa to make evidence-based decisions about whether to add HepB-BD into the national immunization programs.

Impact of 13-valent pneumococcal conjugate vaccine on the incidence of hospitalizations for all-cause pneumonia among children aged less than 5 years in Burkina Faso: An interrupted time-series analysis.

BACKGROUND: Pneumococcal disease is a major public health concern globally and particularly in Burkina Faso, where the 13-valent pneumococcal conjugate vaccine (PCV13) was introduced nationwide into the routine immunization schedule in 2013. The aim of this study was to evaluate vaccine impact on all-cause pneumonia hospitalizations among children <5 years of age. METHODS: Hospitalization data covering a 10-year period (January 1, 2009-December 31, 2018) were collected retrospectively in four rural district hospitals, using medical records to extract data on relevant variables. Using an interrupted time-series design and segmented regression, the effectiveness and impact of PCV13 on the rates of pneumonia hospitalization were estimated. Severe acute malnutrition and unintentional injury were used as control conditions. RESULTS: Vaccine effectiveness was found to be 34% (95% confidence interval (CI) 16-49%, p=0.001), 24% (95% CI 2-41%, p=0.032), and 50% (95% CI 30-64%, p<0.001) against all-cause pneumonia among children <5 years, <2 years, and 2-4 years of age, respectively. By October 2018, PCV13 introduction had led to an absolute reduction in the pneumonia hospitalization rate of 348 cases per 100000 person-years among children <5 years of age. No decline was observed for the control conditions. CONCLUSIONS: These estimates point to a substantial public health impact of PCV13 against pneumonia hospitalization among children aged <5 years in Burkina Faso.

Quality and reliability of vaccination documentation in the routine childhood immunization program in Burkina Faso: Results from a cross-sectional survey.

INTRODUCTION: Accurate and timely vaccination data are important to the Expanded Program on Immunization (EPI) to assess individual vaccination status and to monitor performance and vaccine coverage (VC). Since 2013, Burkina Faso introduced several new vaccines into the routine childhood immunization schedule. However, sustained efforts for a timely update and alignment of immunization home-based (HBRs) and health facility-based records (FBRs) with the evolving schedule were not implemented. METHODS: In 2016-17, we conducted a 6-week cross-sectional survey in 30 health facilities (HFs) across 10 health districts (HDs), targeting children aged < 24 months and their caregivers. Data collected included sociodemographics, availability of vaccination recording fields in HBRs, and vaccination dates. We evaluated the characteristics, completion patterns, and concordance of HBRs and FBRs to determine their reliability as data sources in estimating VC. A standard HBR was defined as one that had recording fields for all recommended 17 vaccine doses of the schedule, and discordance between HBR and FBR as having different vaccination dates recorded, or vaccination information missing in one of the records. We computed proportions and concordance statistics, and used logistic regression to explore predictors of discordance. RESULTS: We recruited 619 children, including 74% (n = 458) aged 0-11 months. Half (50.6%) of HBRs were non-standard. About two-thirds (64.6%) of children were concerned with discordant information. Compared to HBRs, FBRs were generally associated with low negative predictive values (median: 0.41; IQR: 0.16-0.70). Multivariate logistic regression model showed that standard HBR was protectively associated with discordant information (OR = 0.46, 95% CI: 0.26-0.81, p = 0.010). CONCLUSION: We documented a lack of standardization of HBRs and frequent information discordance with FBRs. There is a pressing need to update and standardize vaccination recording tools and ensure their continuous availability in HFs to improve data quality in Burkina Faso.

Immunogenicity and Reactogenicity of 13-Valent Pneumococcal Conjugate Vaccine Among Infants, Toddlers, and Children in Western Burkina Faso: Results From a Clinical Trial of Alternative Immunization Schedules.

BACKGROUND: Many African countries have introduced pneumococcal conjugate vaccine (PCV) into their routine immunization program to reduce the burden of morbidity and death that results from Streptococcus pneumoniae infection, yet immunogenicity and reactogenicity data from the region are limited for the 2 available PCV products. METHODS: We conducted a randomized trial of 13-valent PCV (PCV13) in Bobo-Dioulasso, Burkina Faso. Infants received 3 doses of PCV at 6, 10, and 14 weeks of age or at 6 weeks, 14 weeks, and 9 months of age; toddlers received 2 doses 2 months apart or 1 dose beginning at 12 to 15 months of age; and children received 1 dose between 2 and 4 years of age. We measured each participant's serotype-specific serum immunoglobulin G concentration and opsonophagocytic activity before and after vaccination. For each age group, we compared immune responses between study arms and between the standard schedule in our study and the PCV13-licensing trials. RESULTS: In total, 280 infants, 302 toddlers, and 81 children were assigned randomly and underwent vaccination; 268, 235, and 77 of them completed follow-up, respectively. PCV13 resulted in low reactogenicity in all the study arms. The vaccine elicited a strong primary immune response in infants after 2 or more doses and in children aged 1 to 4 years after 1 dose. Infants who received a booster dose exhibited a robust memory response. Immunogenicity was higher than or comparable to that observed in the PCV13-licensing trials for a majority of serotypes in all 3 age groups. CONCLUSIONS: PCV13 has a satisfactory immunogenicity and reactogenicity profile in this population. Our findings will help support decision making by countries regarding their infant and catch-up vaccination schedules.