Bay Area Flu Levels Reach New Seasonal High

Experts warn of potential new wave of influenza B cases as multiple strains circulate

Published on Feb. 11, 2026

Got story updates? Submit your updates here. ›

Flu season is hitting hard in California, with the Bay Area reporting the highest positivity rates of the season so far. While influenza A remains the dominant strain, health officials are also seeing an increase in influenza B cases, which could lead to a second wave of infections.

Why it matters

The rise in flu cases, including the emergence of a new strain, is concerning as it could overwhelm healthcare resources and lead to more severe illness, especially for vulnerable populations. Public health experts emphasize the importance of getting vaccinated, even late in the season, to provide protection against both influenza A and B.

The details

The latest data from the California Department of Public Health shows that 18.99% of flu tests in the Bay Area were positive as of January 31st, the highest level so far this season. Central and Northern California are reporting even higher positivity rates of 23% and 26% respectively. While influenza A remains the dominant strain, health officials are also seeing an increase in influenza B cases, which could lead to a second wave of infections.

  • Flu season is typically at its peak in February.
  • As of January 31st, the Bay Area reported a 18.99% flu test positivity rate, the highest of the season so far.

The players

Dr. Monica Gandhi

An infectious disease specialist at UC San Francisco who explained that it's not unusual for a second flu strain to emerge midway through the season, and that people can potentially get sick with the flu twice in one season.

Got photos? Submit your photos here. ›

What they’re saying

“This could lead to a whole new wave of influenza cases.”

— Dr. Monica Gandhi, Infectious disease specialist, UC San Francisco (sfgate.com)

What’s next

Health officials are urging residents to get vaccinated, even late in the flu season, to protect against both influenza A and B strains. They are also monitoring the situation closely for any further increases in cases.

The takeaway

The rise in flu cases, including the emergence of a new influenza B strain, underscores the importance of vaccination and vigilance, especially as large gatherings like the Super Bowl could lead to further virus spread. Staying up-to-date on flu shots and taking precautions can help mitigate the impact of this potentially severe flu season.