Flu Season Looks Green in September

Since the summer of 2025 has ended, and most children have returned to school, parents are asking when the best time is to get the annual flu shot. Since it takes a few days for influenza vaccines to take effect, timing is a crucial factor.

To help guide answers, the U.S. Centers for Disease Control and Prevention (CDC) recently published the results of tests performed by clinical laboratories nationwide.

Nationally, during Week 36, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories was 0.4%.

The CDC also confirmed that, based on NCHS mortality surveillance data available as of September 4, 2025, 0.06% of the deaths that occurred during the week ending Week 36 were attributed to influenza. 

Unfortunately, a total of 280 influenza-associated pediatric deaths occurred during the 2024-2025 season.

This data is the highest number of pediatric deaths reported in any non-pandemic influenza season since the condition became reportable in 2004.

To reduce these pediatric deaths, the CDC and most state health departments recommend that eligible children receive the flu shot beginning in September each year.

Additionally, adults and children should be protected when traveling to a country reporting influenza outbreaks, such as Australia. Influenza vaccination is recommended for all Australians aged 6 months and older for the 2025-2026 flu season.

As of September 15, 2025, most pharmacies in the USA offer vaccine appointments to streamline the flu shot programs.