Hepatitis A Virus Vaccine Escape Variants and Potential New Serotype Emergence

Abstract

Six hepatitis A virus antigenic variants that likely escaped the protective effect of available vaccines were isolated, mostly from men who have sex with men. The need to complete the proper vaccination schedules is critical, particularly in the immunocompromised population, to prevent the emergence of vaccine-escaping variants.

Hepatitis B and E Co-Primary Infections in an HIV-1-Infected Patient

“…Of note, he became infected with HBV genotype G, which is rare in France and worldwide but has been described to be more frequent in HIV-infected patients (34)(35)(36) and particularly among MSM (37)(38)(39). Also, we searched for top hits in the NCBI sequence database with the HAV sequence recovered from a patient's serum collected 1 year before HEV-HBV primary infection, and we found three HAV sequences with 100% nucleotide identity that were obtained from serum samples of MSM in Barcelona, Spain (40).…”

Molecular epidemiology of hepatitis A virus infections in Catalonia, Spain, 2005–2009: Circulation of newly emerging strains

“…Nevertheless it may be explained bearing in mind the quasispecies distribution of HAV 14 and the selective pressure imposed by a partial immune response in vaccinated HIV+ patients. 15 Thirty-one different strains were detected from 54 sporadic cases. Three strains were detected in both sporadic and outbreaks cases.…”

Hepatitis A: Clinical, Epidemiological and Molecular Characteristics

“…These findings suggest that beyond mutations and genetic recombination, HAV exploits variation strategy in dominance to promote and ensure its survival. Despite some degree of nucleotide heterogeneity at the capsid region of HAV, there is not an equivalent degree of amino acid variation (Aragonès, 2008;Pérez-Sautu, 2011). Severe structural constraints in the hepatitis A virus capsid prevent more extensive substitutions necessary for the emergence of new serotype, and hence existence of single serotype of human HAV (Bosch, 1998).…”