Blue States Turn Green With Influenza

Seasonal influenza continues to circulate at elevated levels across the United States in mid-February 2026, with health officials from the Centers for Disease Control and Prevention (CDC) noting a shift in the dominant strains driving infections.

According to the CDC's latest Weekly U.S. Influenza Surveillance Report for 2026, seasonal influenza activity remains high nationally. Influenza A activity is decreasing, while influenza B activity is increasing both nationwide and in most regions of the country. Influenza A(H3N2) viruses have been the most commonly reported subtype this season so far.

However, these trends show notable regional variability.

Regional differences are particularly evident in supplementary tracking tools.

The Walgreens Respiratory Index©, which monitors respiratory illness trends using prescription, testing, and over-the-counter product data from Walgreens locations, illustrates this variability in mid-February 2026.

Numerous states in the eastern portion of the country have shifted to green, indicating lower relative intensity compared to baseline levels. In contrast, states in western areas continue to show red, representing the highest intensity category.

The Index also highlights maximum intensity in several southern states, including Alabama, Arizona, Florida, and Mississippi, where respiratory illness activity—driven largely by ongoing flu circulation—remains at peak levels.

Health experts emphasize that while influenza A declines in many places, the rise in influenza B could sustain elevated activity or lead to prolonged circulation in certain regions.

Officials continue to recommend vaccination.

"This flu season is exceptionally active," commented Anita Patel, vice president of Pharmacy Services Development at Walgreens, in a January 2026 press release.

"To protect yourself and others, I encourage everyone to get vaccinated as soon as possible, wash your hands frequently, and if you're feeling symptoms, get tested right away," Patel says.

The CDC updates its FluView surveillance weekly, and activity levels can fluctuate. For the most current data, visit the CDC's FluView website.

Furthermore, when traveling abroad, check the CDC's Travel Health Notices for information on disease outbreaks in other countries and related travel vaccine options.