On Oct. 22, 2021, the Centers for Disease Control and Prevention (CDC) reported two new U.S. human infections with influenza viruses that usually spread in pigs and not people. These types of infections are called ﾓvariant influenza virusﾔ infections and denoted with the letter ﾓvﾔ after the influenza subtype.

One of these variant influenza virus infections is the first to occur during the 2021-2022 flu reporting season (i.e., from October 2021 through September 2022) and the other reported infection is the 11th infection that occurred during the 2020-2021 season (i.e., from October 2020 through September 2021).