US health experts recommend October timing for flu vaccinations

Health experts are advising Americans to prepare for the upcoming flu season following a severe respiratory period. During the 2025-2026 season, the United States recorded at least 32 million flu cases, 390,000 hospitalizations, and 24,000 deaths. This surge was largely attributed to subclade K, a heavily mutated form of the Influenza A (H3N2) virus.

While pharmacies often begin stocking vaccines in August and promoting them in September, medical professionals suggest that October is the ideal time for vaccination. Because the vaccine typically provides protection for six to eight months, getting the shot too early may result in diminished immunity before the season concludes.

According to the CDC, flu activity in the US generally begins to rise in October, peaks between December and February, and declines in the spring. Vaccination is recommended to reduce the risk of infection and serious complications such as pneumonia or influenza-associated encephalopathy (IAE).