Vaccination remains the most effective way to mitigate the enormous burden of influenza on the health care system. Seasonal influenza vaccines routinely contain three or four virus strains, meaning trivalent or quadrivalent influenza vaccines, TIV or QIV, respectively. The components of the vaccines are based on the recommendations of the WHO and FDA’s Vaccines and Related Biological Products Advisory Committee, yearly or bi-annually. Recently, most human infections were caused by variants two i...