NorCal Hit With First Child Flu Deaths Of The Season As Cases Surge

SAN MATEO COUNTY, CA — As flu cases in the Bay Area spike following the holidays, Northern California health officials confirmed two flu deaths of children over the holidays.

This week, San Mateo County Health confirmed the flu death of an unvaccinated adolescent who died in December. Officials in Sacramento County also confirmed the flu death of a child there over the holidays. Neither were described as having underlying health conditions.

“We are deeply saddened by the loss of a young person in our community to influenza,” said Dr. Kismet Baldwin-Santana, San Mateo County health officer. “There are steps people can take to protect themselves and those around them, including getting vaccinated, staying home when sick and practicing preventative measures.”

Flu-related activity is on the rise across the Bay Area, health officials said. Key indicators tracking flu activity— emergency department visits and test positivity — are increasing, though they remain consistent with historical levels, officials said.

According to state health officials, the Bay Area confirmed more than 4,000 flu cases in the last week of 2025, roughly seven times the number of cases confirmed at the start of December.

The California Department of Public Health recommends that everyone six months of age and older receive the vaccine. You can obtain the vaccination through most pharmacies or health care providers.

Uninsured residents can call San Mateo County Health’s Health Coverage Unit at 650-616-2002 for vaccination options. Homebound individuals whose provider does not offer in-home vaccination can register for an appointment by calling Aging and Disability Services at 844-868-0938.

“Vaccination remains our strongest protection,” Dr. Baldwin-Santana said. “Getting the flu shot helps protect not only yourself but also your family, classmates and neighbors. We urge everyone who is eligible to get vaccinated and to take flu symptoms seriously.”

San Mateo County recorded 18 influenza-related deaths among persons under 65 during the 2024-25 season, compared to 9 such deaths in 2023-24, officials said.

A predicted surge of influenza cases, driven by the new “subclade K” mutation, is hitting California. Flu activity is high or very high in 48 states and jurisdictions, according to the latest data from the Centers for Disease Control and Prevention. At least 11 million people have gotten sick, and 5,000 have died, including at least 10 children, this season.

The CDC expects the current flu wave to last several more weeks and noted elevated RSV activity, with increased ER visits and hospitalizations for children under four. COVID-19 activity is low but rising nationally. Following the holidays, positive flu cases spiked in California, with most regions reporting "high" or "very high" activity levels.

Flu hospitalizations are still low, according to CDPH, but are expected to increase following spikes in testing and wastewater data. Influenza is a major concern this year due to a more serious season. The subclade K mutation emerged after the vaccine was developed last February, resulting in a mismatch that allows the virus to better evade prior immunity from vaccination or infection.

Health experts urge flu shots, which should protect against severe disease and death. The CDC advises influenza vaccination for everyone 6 months and older not yet immunized this season. About 130 million flu vaccine doses have been distributed in the U.S.

In mid-December, the CDC estimated 42 percent of Americans had gotten their flu shots. Rates vary greatly by age, with around 60 to 70 percent of older adults over age 65 getting their shots. Coverage varies from year to year, but generally falls far short of the 70 percent goal for herd immunity. Some flu seasons have seen vaccine coverage around 47 percent.

The advice to get vaccinated was still on the CDC website on Monday, when the agency announced a major overhaul of the childhood vaccine schedule. Flu shots will be recommended in shared clinical decision-making, an approach adopted last year for most COVID-19 and hepatitis B vaccine recommendations.