Interference with a conformational change in the haemagglutinin molecule of influenza virus by antibodies as a possible neutralization mechanism.

A possible mechanism of neutralization of influenza virus by antibodies to the haemagglutinin molecule is proposed in addition to the generally accepted mechanism of blocking attachment to host cell receptors. This proposed mechanism involves interference with a low-pH-induced conformational change in the haemagglutinin molecule by bivalent binding of antibodies, which results in inhibition of the fusion step in the viral replication process.