The US Centers for Disease Control and Prevention (CDC) has released early data suggesting that this season’s flu vaccine may not match a dominant strain of the flu virus, which has caused widespread infections. According to the CDC, only 50.9% of samples tested against the H3N2 strain were “well-recognized” by the antibodies in the vaccine.
This is significantly lower than the 100% recognition rate seen last year, when the same strain was present. Experts caution that multiple factors can influence how well vaccines work in real-world scenarios, including pre-existing immunity and previous infections.
While some experts warn of a potentially severe season ahead, others note that even with mismatched vaccines, protection is still possible. The CDC is expecting more data soon and will participate in an upcoming World Health Organization meeting to decide next year’s vaccine update.
Source: https://www.cbsnews.com/news/flu-vaccine-match-early-cdc-data-2025