First Flu Deaths Of Season Reported In SF As Cases Surge in California

SAN FRANCISCO, CA — San Francisco Public Health officials confirmed that two people have died from the flu, the first two deaths caused by the virus this season.

Both people who died were adults, according to health officials. It's unclear whether they had any underlying medical conditions, and the status of their vaccinations was not known.

“It is always sad when members of our community pass away because of the flu," San Francisco Health Officer Dr. Susan Philip said in a statement Friday, urging people with symptoms to go to a health care provider. "This unfortunate news is a reminder that the flu should not be taken lightly and that it is not too late to get vaccinated."

The announcement comes as flu activity has surged across California, driven by a new "subclade K" mutation.

The subclade K mutation emerged after the vaccine was chosen for the Northern Hemisphere, last February. Once the mutation became established, there wasn’t time to develop a better-matched vaccine. That leaves more people susceptible because the virus has found a way to evade pre-existing immunity from either an infection or vaccination.

Influenza A strain H3NS has mutated seven times, making the flu a more serious threat than in years past. It caused a severe flu season around the world, including in the U.K., Canada, Japan and Australia. Recent CDC data show that nearly all virus samples since late September were the subclade K mutation.

The CDC said earlier this month that the current influenza wave is expected to last several weeks. The agency also noted that RSV activity is elevated in many areas of the country, with emergency room visits and hospitalizations increasing in children under 4. COVID-19 activity is low but increasing nationally.

San Francisco Health officials say flu activity in the city is also currently high, and they recommend everyone get vaccinated.

"The flu vaccine is the best tool to reduce the risk of severe illness and death, especially for people over the age of 65, infants, people with weakened immune systems, and people with certain chronic conditions such as asthma and heart disease," health officials said. "Vaccines are available at health systems and local pharmacies."

Local Editor Daniella Segura contributed to this report.