XK and infection: These could include for example the effect of antibodies to M2 protein and internal influenza proteins [such as the NP protein; anti NP antibodies have been shown to help clear infection in mice (27)] which might prevent release of virus and subsequent cycles of infection, anti-NA antibodies or anti-HA antibodies targeting regions other than the globular head of the protein [neutralizing antibodies have been found that bind the membrane proximal stem of HA, such as CR6261 (4) and CR8020 (28)].