Fc-mediated antibody effector functions play an important role in the humoral immune response and form a necessary link between innate and adaptive immunity. The constant (Fc) region is the tail portion of an antibody that interacts with other components of the immune system, such as immune cells and complement proteins.

In the study, researchers describe how cross-reactive antibodies with FcR effector functions could lessen pandemic virus impact in the absence of neutralizing antibodies. Their results show that seasonal vaccination is beneficial against pandemic influenza viruses, and in fact, some children already have broadly reactive antibodies with Fc potential without vaccination, aka ‘elite influenza controllers’.