Could We Soon Experience a Second Pandemic, from an Influenza Virus?

As the COVID-19 pandemic continues to unfold, we soon could face another. Investigators from the Chinese CDC and WHO have been monitoring influenza strains in pigs carefully since 2011. Pigs are susceptible to many swine, avian, and human influenza viruses, and thereby serve as “mixing vessels” for the emergence of new influenza viruses.

In recent years, a new H1N1 influenza strain (G4 virus) has emerged and become predominant. It binds readily to human-type receptors. Compared with the 2009 H1N1 pandemic virus, it replicates more exuberantly in human respiratory tract epithelial cells. It also efficiently infects ferrets, an animal model for human influenza, and spreads between animals by aerosol transmission. The new strain and other human…