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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.

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.