Compared protective effect of nasal immunoprophylaxis using a new human monoclonal IgM antibody, human polyclonal antibodies, F(ab')2, amantadine, and zanamivir for prophylaxis of influenza A virus pneumonia in mice.

This study evaluated the effectiveness of five human monoclonal antibodies in comparison with human polyclonal antibodies, F(ab')2, amantadine, and zanamivir in a mouse model of lethal influenza A virus infection. A single intranasal administration of antibodies was done for immunoprophylaxis. Zanamivir was administered intranasally and amantadine was administered orally. Mice were fully protected by a single dose of 30 mg/kg intravenous Ig administered at least 3 days before challenge. This treatment was equivalent to zanamivir. F(ab')2 were less effective (p < 0.001). One of the monoclonal antibodies tested was less efficient than both zanamivir (p < 0.001) and intravenous Ig (p < 0.001) but similar to amantadine.