Complement and natural antibody are required in the long-term memory response to influenza virus.

Complement, complement receptors and natural antibody (IgM) are important factors in the immune response against pathogens. Previous studies have indicated a role for C3, the complement receptors CD35/CD21 (CR1/CR2), and IgM in the immune response to influenza virus. Nevertheless, their contribution to the long-term memory response to this pathogen remains unknown.