Stability of hemagglutinin: toward a universal influenza vaccine

Abstract

Influenza viruses continuously undergo antigenic changes with gradual accumulation of mutations. Due to the drawbacksof current vaccines with low vaccine effectiveness, there is an urgent need for universal vaccine development againstinfluenza viruses. Antigenic variation is an essential strategy of the virus to change epitopes, receptor binding or fusionwith the host membrane and is associated with changes in amino acid sequences of viral proteins. This antigenic driftis largely focused on viral major protein hemagglutinin (HA) that is the major antigen target. It has been recognized thatprimary mutations affecting HA functions require co-mutations that modulate the stability of HA for viral infection, whichis not yet clearly understood. This review summarizes recent advances in the field of influenza vaccines with regard to HAprotein stability.