A serological and molecular survey of hepatitis B in children 15 years after inception of the national hepatitis B vaccination program in eastern China.

The emergence of mutations in the hepatitis B virus (HBV) S gene has threatened the long-term success of vaccination programs since the worldwide introduction of effective vaccines against hepatitis B. This study was conducted on 5,407 children (0-8 years old) in eastern China in 2007. We analyzed the prevalence of HBsAg, anti-HBs, and "a"-determinant mutations in the HBV S gene by microparticle enzyme immunoassays, PCR, and DNASTAR software. The total HBsAg prevalence was 1.52% (82/5,407) in the children and increased with age. In contrast, the positive rate (65.42%, 2,374/3,629) and the titers of anti-HBs decreased with age. The predominant infection was HBV of genotype C and serotype adr (45/51; 88% of cases). Mutations of I126T, amino acid 137 (nt553T deletion mutation), G145A, G145R, and F158S were found in the children; the mutations of amino acid 137 and F158S have not been reported previously. The total prevalence of mutant strains was 14% (7/51). To investigate whether the infection resulted from maternal transmission, we compared the S gene sequences in 16 mother-child pairs. Fourteen mother-child pairs exhibited the same HBV genotype, with 99.5-100% sequence homology in the S gene, while two pairs exhibited different genotypes. This study suggested that the hepatitis B vaccination strategies in eastern China have been successful. Although the emergence of "a"-determinant mutations in the HBV S gene have resulted in HBV infection in immunized children, this does not pose a threat to the vaccination strategies. The HBV-infected children had contracted the infection via vertical transmission.

Human papillomavirus vaccination and the risk of autoimmune disorders: A systematic review and meta-analysis.

INTRODUCTION: Human papillomavirus (HPV) vaccination has been proven to effectively protect against HPV infection and infection-associated cancer. However, there are concerns about the relationship between HPV vaccination and the risk of autoimmune disorders (ADs). Therefore, we performed a systematic review and meta-analysis to comprehensively evaluate the relationship between HPV vaccination and ADs risk. METHODS: To identify relevant studies, we conducted a systematic search in EMBASE and PubMed databases of scientific articles published through June 2018. Fixed or random effects models were adopted to estimate overall relative risk. RESULTS: In total, 20 studies (12 cohort studies, 6 case-control studies, and 2 randomized controlled trials) involving more than 169,000 AD events were included in our meta-analysis. Our results show that HPV vaccination was not associated with an increased risk of subsequent ADs (odds ratio [OR] = 1.003, 95% confidence interval (CI): 0.95-1.06), particularly among those with a prior ADs (OR = 0.82, 95% CI: 0.7-0.96). Most of the subgroup analysis results based on the location or type of ADs were consistent with the overall results. CONCLUSION: No evidence of an association between HPV vaccination and ADs was found. Given the low number of estimates for individual AD, additional and larger observational studies are needed to verify our findings.