Preliminary findings from ongoing testing by the Centers for Disease Control and Prevention (CDC) indicate that Americans have little to no pre-existing immunity to the H5N1 avian flu virus found on dairy and poultry farms. The CDC’s conclusions are based on blood samples collected from the 2021-2023 flu seasons. These samples showed low antibody levels against the H5N1 virus, suggesting minimal immunity. Despite this, the risk to the general public remains low, according to CDC, with only 3 human infections reported, all of which involved individuals who worked closely with dairy cows.
Number of infected herds grows: There are at least 92 H5N1 outbreaks in dairy herds in 12 states so far. Continuing support strategies aim to maximize protection of farm workers, who may be at high risk for infection.