High variability of influenza B virus (IBV) hemagglutinin (HA) impairs the cross- neutralization ability of vaccines, leading to reduce efficacy. We identified significant differences in cross-neutralization between IBV strains B/Wyoming/06/2014 and B/Brisbane/60/2008, which differ in only three amino acid residues. The 214 T point mutation was found to dramatically enhance cross-neutralization (>10-fold). Antibody-based reverse validation also revealed that this mutation significantly increased the neutralization capacity (500-62,500-fold). Furthermore, monitoring revealed that the mutation rate at this site has reached its highest level in nearly 20 years, with a prevalence exceeding 80% in sequences submitted from certain regions. Our findings provide new evidence for the selection of vaccine strains with improved cross- neutralization effects, which will aid the development of broad-spectrum vaccines by modifying minimal antigenic epitopes.
[1]Jilin Univ, Sch Life Sci, Natl Engn Lab AIDS Vaccines, Changchun, Peoples R China.
[2]Natl Inst Food & Drug Control NIFDC, Inst Biol Prod Control, Div HIV AIDS & Sexually Transmitted Virus Vaccines, Beijing, Peoples R China.
[3]WHO Collaborating Ctr Standardizat & Evaluat Biol, Beijing, Peoples R China.
[4]Peking Union Med Coll, Grad Sch, Beijing, Peoples R China.
[5]Shenyang Pharmaceut Univ, Sch Pharm, Shenyang, Peoples R China.
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