Vaccine design of hemagglutinin glycoprotein against influenza

Influenza viruses continue to cause annual epidemics and pose the threat of a deadly global pandemic. Vaccination has remained the best approach for prevention and control of influenza infection. However, current influenza vaccines are only effective against closely-matched circulating strains, and therefore must be updated and administered every year. In this review, we discuss recent developments in the search for better influenza vaccines, especially using the major virus surface glycoprotein hemagglutinins (HAs). Understanding how glycans on HAs affect the immune response and knowledge of how broadly neutralizing antibodies are induced will pave the way for a cross-protective influenza vaccine that does not require frequent updates or annual immunizations.