Evolutionary trends of A(H1N1) influenza virus hemagglutinin since 1918.

ABSTRACT: The Pandemic (H1N1) 2009 is spreading to numerous countries and causing many human deaths. Although the symptoms in humans are mild at present, fears are that further mutations in the virus could lead to a potentially more dangerous outbreak in subsequent months. As the primary immunity-eliciting antigen, hemagglutinin (HA) is the major agent for host-driven antigenic drift in A(H3N2) virus. However, whether and how the evolution of HA is influenced by existing immunity is poorly understood for A(H1N1). Here, by analyzing hundreds of A(H1N1) HA sequences since 1918, we show the first evidence that host selections are indeed present in A(H1N1) HAs. Among a subgroup of human A(H1N1) HAs between 1918 approximately 2008, we found strong diversifying (positive) selection at HA(1) 156 and 190. W

SUBMITTER: Shen J 

PROVIDER: S-EPMC2773012 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature