The 2009 Pandemic H1N1 Hemagglutinin Stalk Remained Antigenically Stable after Circulating in Humans for a Decade.

ABSTRACT: An H1N1 influenza virus caused a pandemic in 2009, and descendants of this virus continue to circulate seasonally in humans. Upon infection with the 2009 H1N1 pandemic strain (pH1N1), many humans produced antibodies against epitopes in the hemagglutinin (HA) stalk. HA stalk-focused antibody responses were common among pH1N1-infected individuals because HA stalk epitopes were conserved between the pH1N1 strain and previously circulating H1N1 strains. Here, we completed a series of experiments to determine if the pH1N1 HA stalk has acquired substitutions since 2009 that prevent the binding of human antibodies. We identified several amino acid substitutions that accrued in the pH1N1 HA stalk from 2009 to 2019. We completed enzyme-linked immunosorbent assays, absorption-based binding assays, a

SUBMITTER: Christensen SR 

PROVIDER: S-EPMC9175623 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature