Immunogenicity of Hepatitis B Vaccine in Preterm or Low Birth Weight Infants: A Meta-Analysis.

CONTEXT: The study aims to quantitatively assess the immune response to hepatitis B vaccine in infants born preterm or with low birth weight. EVIDENCE ACQUISITION: In December 2018, a literature search was conducted in 4 databases without date restrictions. The pooled ORs, mean differences, and their corresponding 95% CIs were calculated with random-effects models using the DerSimonian-Laird estimator. The potential risk of bias of each study was assessed using the Newcastle-Ottawa Scale. The stability and publication bias of the pooled estimates were also evaluated. Analyses were completed in 2019. EVIDENCE SYNTHESIS: A total of 27 studies including 22,202 infants were eligible for analysis. The studies found that infants born preterm had significantly poorer immune responses to the hepatitis B vaccine. Preterm infants were 1.36 times more likely to exhibit nonresponse to the hepatitis B vaccine (95% CI=1.12, 1.65, p=0.002) compared with their full-term counterparts. The pooled estimates for preterm birth may be subject to a potential publication bias. However, these results were stable, as suggested by the leave-one-out analysis and fail-safe number. The association between low birth weight and impaired immune response to the hepatitis B vaccine was not statistically significant when birth weight was dichotomized at 2,500 g. CONCLUSIONS: These findings suggest an association between preterm birth and lowered immune responses to hepatitis B vaccine.