A systematic review reveals that African children of 15-17 years demonstrate low hepatitis B vaccine seroprotection rates

Childhood HBV immunization remains globally fundamental to the elimination of hepatitis B virus (HBV). However, monitoring proportions of HBV vaccine seroprotection and their determinants among African Pediatric recipients is crucial. This study sought to verify extent of immune protection accorded by the HBV vaccine in African children of up to 17 years of age by pooling the prevalence of seroprotection reported by primary studies conducted in the Northern, Western, and Southern African regions. We included 19 eligible articles out of the 197 initially downloaded, published from 1999 to 2021 from African Journals Online (AJOL), EMBASE, Scopus, and PubMed. The study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO), University of York Centre for Reviews and Dissemination, under the registration number CRD42022361277. Significantly higher (p < 0.0001) proportion of HBV vaccine seroprotection (69.07%) was found among children under 15 years of age than children 15-17 years (32.368%), 95% CI [34.2454-39.0847%]. Whereas successful integration of the HBV vaccine on the extended programs on immunizations (EPI) has been a major achievement in the reduction of HBV infection in Africa, markedly reduced HBV vaccine seroprotection is persistently demonstrated among adolescent children 15-17 years of age. Future studies are required to clarify the need for booster dose vaccination in most at risk populations and age groups.

Antitetanus toxoid antibodies in mothers and neonates: a single-centre study from Uganda

BACKGROUND

Neonatal mortality due to tetanus persists in Uganda despite the mandatory vaccination of pregnant mothers. Maternal antibodies wane within a year. Uganda's maternal vaccination guidelines do not specify the timing or frequency of tetanus shots, contributing to suboptimal transfer of tetanus antibodies to neonates. We aimed to determine the prevalence and factors associated with protective tetanus antibodies among newborns at Kawempe National Referral Hospital.

METHODS

We conducted a cross-sectional study among 293 mother-newborn pairs. At delivery, neonatal cord and maternal venous blood were collected and titred for antitetanus antibodies using a quantitative ELISA kit. The primary outcome of the study was the proportion of newborn babies with tetanus antibodies ≥0.1 IU/mL. Associated factors were determined using generalised linear models for the Poisson family with a log link and robust variance estimation.

RESULTS

A total of 258/293 (88.1%) newborns had protective antibody titres. Factors associated with adequate protective antibodies in the newborn included: high (≥0.1 IU/mL) maternal antibody titres, first antenatal visit ≥12 weeks of gestation and receiving a tetanus toxoid (TT) shot ≥28 weeks of gestation. However, number of doses received before current pregnancy was not associated with adequate protective antibody titres.

CONCLUSION

There is a high prevalence of adequate protective levels of antibodies among TT-vaccinated mothers. Maternal titres and a third trimester TT dose correlate with adequate levels of protective anti-TT antibodies among newborns. A third trimester TT dose is recommended.