California’s Worst Flu Season in Years May Finally Be Easing

California may finally be getting a reprieve from one of the worst recorded flu seasons in decades, a recent report by state health officials shows.

• Jump straight to: It’s not too late for a flu shot — and here’s where to find the vaccine

For the week ending Feb. 15, 23.3% of tests conducted by the state’s clinical labs were positive for influenza, making up a week-over-week drop of 3.4 percentage points, according to the report released Friday by the Department of Public Health. That decline was more than triple the one seen the week before.

While the decrease in testing positivity rates could be a sign that the season has passed its peak, some health experts are warning that numbers could go up again and urge those who haven’t been vaccinated yet to do so as soon as possible.

A similar drop was reported in early January but only lasted a couple of weeks before rates climbed up again, said Dr. John Swartzberg, clinical professor emeritus at the UC Berkeley School of Public Health, noting that flu season typically peaks around the middle of February.

“It’s possible we could get lulled into the same mistake that we made in the middle of January … but I think this drop coincides more with what we typically see with influenza,” Swartzberg said. “I’m cautiously optimistic.”

The Centers for Disease Control and Prevention estimates that there have been at least 33 million confirmed cases of influenza, 430,000 hospitalizations and 19,000 deaths across the country during this flu season alone.

In California, influenza activity remains high even as numbers begin to go down, and at least 15 children have died from flu-related complications — raising concerns about declining pediatric vaccination rates. Swartzberg said it’s worrying to see so many pediatric deaths because children tend to be resilient when it comes to fighting illnesses outside of infancy.

The two influenza strains circulating most rapidly this flu season are H1N1 and H3N2, both of which are influenza-type A strains. As the rate of those infections begins to go down, however, Swartzberg said there is another type of influenza circulating — influenza type B — and those numbers usually go up around March, which could result in another peak.

“We may continue to see influenza A drop, but then the number of cases of influenza could go back up because influenza B is starting to play a role,” Swartzberg said. “We’ve seen that pattern over the last several years.”

Experts can only speculate as to why the rates of infection are so much higher this year, Swartzberg said, adding that several factors, such as a decrease in the use of masks in crowded spaces and lower vaccination rates, could be contributing.

People have been less diligent about getting their flu shots since the COVID-19 emergency ended, and herd immunity is way down, Swartzberg said. Additionally, since many people have had less exposure to the flu in recent years, they’re naturally more vulnerable to the respiratory illness, he added.

While the CDC recommends that everyone 6 months and older get the flu vaccine as early as possible — ideally in the fall — it’s never too late to get vaccinated, especially since the virus is still circulating.

“If you haven’t been vaccinated, you’ll get some immunity within a week of the vaccine, and you get your optimal immunity within two weeks of the vaccine,” Swartzberg said. “The vaccine may not prevent you from getting infected or even getting sick, but it’s quite good at preventing that sickness from getting really bad.”

Where can I find a flu shot?

Although the CDC recommends that everyone 6 months and older get an annual flu vaccine “ideally by the end of October,” the agency also said that people “should continue to get vaccinated as long as flu viruses pose a threat to their community.”

That means that if you forgot to get your shot back in the last months of 2024 — and you haven’t been hit by a flu infection yourself this winter — it’s not too late to get the flu vaccine now and increase your protection.

If you have health insurance, a flu shot is covered and available without extra cost as a preventive service from your usual health care provider. It’s also available at most pharmacies (see below).

Common places to find a flu shot appointment, walk-in site or drive-thru flu shot:

• CDC’s Find Flu Vaccines tool
• Kaiser Permanente flu shots (Northern California)
• CVS flu shots
• Walgreens flu shots
• Rite Aid flu shots
• Costco Pharmacy flu shots
• Albertsons (Safeway) flu shots

If you don’t have health insurance, you can get the vaccine free of charge from several providers and community clinics around the Bay Area. (You can also technically use these free services even if you do have insurance, but you may consider choosing to reserve these particular resources for those without coverage.)

Your county’s public health department may also be offering flu shots.

Places to get a free or low-cost flu shot in the Bay Area include:

• San Francisco Department of Public Health’s AITC clinic (offers a pay-what-you-can option.)
• Contra Costa Public Health Immunization Clinic (flu shots are $15 for adults over 19, but fees may be waived if you cannot pay.)
• Alameda County Immunization Clinics.

KQED’s Natalia Navarro contributed to this report.