Hepatitis B vaccine effectiveness in the face of global HBV genotype diversity

Abstract

Recombinant hepatitis B vaccines are of the A2 genotype; one of ten known genotypes whose distribution varies globally. Reports of rare HBV infections in blood donors with an imbalance of non-A2 genotype HBV in vaccinated subjects have raised questions about the cross-protection afforded by HBV-A2 vaccines. Infections in HBV vaccinees were asymptomatic and transient, indicating that vaccination prevented clinical disease. Preclinical data demonstrate cross-reactivity and cross-protection by A2 vaccines against non-A2 HBV genotypes. Substantial improvements in HBV control have been demonstrated in countries with diverse genotype distribution that have introduced universal childhood HBV vaccination programs. Available data show that current HBV-A2 vaccines are highly effective in preventing infections and clinical disease caused by all known HBV genotypes.

Molecular identification of hepatitis B virus genotypes/subgenotypes: Revised classification hurdles and updated resolutions

“…The current vaccine is derived from genotypes A and D of HBV [104] . Despite its success in most cases, there are several reports of vaccination failure due to genotype complications [105] . In one case, a German patient who was vaccinated and showed production of formally protective anti-HBs antibodies developed acute hepatitis B following infection with genotype F of HBV [104] .…”

Serological and molecular epidemiological outcomes after two decades of universal infant hepatitis B virus (HBV) vaccination in Nunavut, Canada

“…The HBV vaccine is a recombinant component vaccine containing HBsAg produced from yeast cells [84]. The vaccine utilizes a genotype A2 sequence, which has been shown to be protective across all genotypes, as the majority of protective antibodies are produced against HBsAg within the very conserved 'a' determinant region.…”

Sero-Molecular Epidemiology and Risk Factors of Viral Hepatitis in Urban Yemen

“…The HBV genotypes differ in their response to pegylated IFN-α, genotype A strains respond well, while genotypes D, B and C showed reduced response. In contrast, the response to nucleoside/nucleotide analogues is independent of HBV genotypes (Brunetto et al, 2013;Westland et al, 2003;Cooksley, 2010;Cassidy et al, 2011). Possible risk factors for Hepatitis B and C in Yemen are non-adherence to universal infection control precautions in high risk situations like hemodialysis, blood transfusion, dental clinics, barber shops, circumcision, ear pricing and folk medical practices (Al Waleedi and Khader, 2012).…”