Flu surges, we're not Denmark, and helping people with serious mental illness
The CA Dose, December 23, 2025
Happy holidays! It’s beginning to feel a lot like flu season. RFK Jr. almost pulled a fast one with childhood vaccines. And imperfect state mental health policies are getting needed attention. Let’s start with flu.
Infectious disease “weather report”
Flu season has shifted into high gear across California. Statewide average test positivity rates are four times higher than they were three weeks ago. In Los Angeles County, where rates are highest, one in ten tests for respiratory virus symptoms are now positive for flu.
Covid, Flu, and RSV test positivity, July-December 2025, California
Judging from our patterns over the years, we should expect flu virus transmission to be elevated in California for the next four months at least. From this point, we typically see rapidly rising rates for at least six weeks, with an eventual steady decline into mid-spring.
The dominant strain of flu nationally is H3N2 subclade K— the same flu variant that’s driven spread in England, Japan and Australia. This year’s flu shot isn’t a perfect match, but studies show it’s holding it’s own against subclade K. In England, where the virus hit months ago, the vaccine was 70-75% effective at preventing hospitalization in children, and 30-40% effective for adults.
The effectives of the vaccine for protecting children is reassuring. This week, the CDC noted the nation’s first two pediatric influenza deaths this season. Over the course of last year’s flu season we lost 44 children in California, and almost all weren’t fully vaccinated.
RSV levels are also steadily rising statewide.
Covid levels remain low, but the virus is stirring in the East and Midwest. Wastewater levels are lowest in the West, but I suspect we’ll be close behind our neighbors to the east.
Covid wastewater levels by U.S. region, 2025
Holiday travel and gatherings, which mostly happen indoors, will accelerate transmission of all respiratory viruses. That’s one reason we typically see flu, RSV, and Covid all up at the same time in January. If you’re not vaccinated yet, especially if you’re over age 65 or in another high risk group, now is the time—this year’s grace period, with a late start to the virus season, is ending.
What this means for you:
Mask up in crowded indoor places if you don’t want to get sick. I’m masking in the airport, knowing I’m mixing with people from places with high levels of transmission of any respiratory virus.
If you’re sick, stay home. A flu test can help diagnose illness early enough to benefit from treatment— antivirals like oseltamivir (Tamiflu) can shorten duration of illness if started within a couple days of symptom onset.
Importantly, it’s not too late to get vaccinated! Vaccines are available across California. You can visit MyTurn to schedule a vaccine today.
The next big challenge to childhood vaccines
You may be seeing headlines that RFK Jr. plans for the nation to adopt Denmark’s childhood vaccine schedule—wholesale, and all at once. This would mean fewer vaccines and less protection for our kids.
While a press conference was announced for last Friday, it was quickly cancelled again because it’s not clear whether this sweeping change is even legal. The American Academy of Pediatrics has filed a lawsuit against the federal government for changing recommendations without full scientific review. But the Denmark proposal seems to be on the table, and it’s worth understanding what’s at stake.
How does the Danish system differ from ours?
The Danes don’t routinely vaccinate children against chickenpox, RSV, rotavirus, hepatitis A or B, meningococcus, flu, or Covid-19—all routine vaccinations across the U.S. and in California.
On Friday, when a colleague in D.C. texted that RFK Jr. planned to adopt Denmark’s vaccination schedule, my first (cheeky) reply was “Great. Can we adopt their health care system too?” Because what makes this possible in Denmark is what surrounds it: universal health care, reliable access to affordable care for sick and well children, 46 weeks of paid parental leave, excellent prenatal screening, centralized medical records with reliable follow-up.
We have none of those things in the U.S. Without them, we have to lean into prevention—which vaccines offer—as much as we can, knowing that families with sick children fall through the cracks and spread preventable diseases in our communities.
The current federal plan to reduce access to vaccines, while adding barriers to accessing health care by cutting insurance benefits is a dangerous pairing of policies.
In California, does it matter anymore what HHS says?
In September, the Governor signed Assembly Bill 144 to ensure that California’s immunization recommendations follow evidence-based guidance from trusted national medical organizations, including the American Academy of Pediatrics (AAP). This also aligns us with the West Coast Health Alliance (WCHA), the four-state coalition to provide regional coordination of science and policy to protect our vaccine access. Still, such a significant change in the childhood vaccine schedule at the federal level would affect Californians.
Decoupling from HHS recommendations can protect insurance coverage and school requirements, but WCHA doesn’t solve everything. (There is still a reason for a federal government!) Some things it doesn’t solve (yet) include:
Vaccines for Children, the program that funds vaccines for more than half of U.S. children. This could be solved with innovative vaccine finance and policy (like purchasing directly from the manufacturer instead of the government) but this comes with a big price tag.
Liability. Providing shots that are not on the HHS vaccine schedule could potentially expose physicians, hospital systems, and pharmaceutical companies to new liability for any and all adverse events. This could discourage clinicians from providing vaccines, and manufacturers could eventually stop making them altogether because it’s too expensive to fight in courts. This is something CA couldn’t solve.
Confusion. Understanding and communicating separate vaccine schedules within the U.S. can add confusion, which itself can reduce vaccine uptake. (But we’re working on this!)
I would also love for WCHA to work on our safety nets: ensuring access to health care for children and families, more paid maternity leave, and centralizing data so people don’t fall through the cracks.
What this means for Californians: Nothing directly, for now. All vaccines are still available. There is a lot happening in our state health care systems, medical societies, WCHA, and our front line pediatricians to make sure the Denmark proposal doesn’t move forward quietly. The Evidence Collective (an initiative founded by YLE founder Katelyn Jetelina) pulled together a short briefing you can find HERE. I’ll keep you up to date if anything important changes.
Mending gaps in our mental health system
The violent loss of Rob and Michele Reiner last week has raised familiar and painful questions about our mental health system, and how to support families when a loved one is too ill to know they need help.
I’ve asked Dr. Aaron Meyer, a psychiatrist specializing in mental health and substance use with the California State Association of Psychiatrists, to help explain a new law that aims to close that gap.
California’s evolving policy approach. One of the most challenging areas for mental health providers is determining whether someone is well enough to make their own decisions, and what to do when they’re not. Protecting personal freedom and civil liberties while providing intervention when someone becomes too ill to care for themselves is a difficult balance.
In 2022, California created the Community Assistance, Recovery and Empowerment (CARE) Court Program, which allows caregivers to petition to have loved ones engaged in voluntary or mandatory outpatient mental health care. The goal is to intervene before they end up in a locked psychiatric unit, jail, or worse. The program focuses on people with serious mental illness who are moving toward grave disability—meaning they can’t meet their basic needs.
What’s changed. CARE court implementation has been challenging, and the law establishing the program has been amended several times since it was introduced. , This July, the CARE Act Annual Report found it had not served nearly as many people as it was intended to. Up to July 2025, counties had received over 3,300 referrals to CARE court, but a full 39% of these were dismissed, often because people didn’t qualify by the narrow criteria. A recent CalMatters investigation also found that there have been no penalties for counties that haven’t provided the required services, among other problems.
A new state law (SB 27), signed by the governor in October, aims to prevent at least some of those people from falling through the cracks, in three ways.
1. Expanded eligibility. The new bill expands the eligible diagnoses, including “bipolar disorder with psychotic features,” a major contributor to mental crisis and self-damaging behavior.
2. Requiring active treatment. SB 27 clarifies that the person has to be in active treatment and showing clinical improvement before being dismissed from the program—and not just enrolled in services they may not be attending.
3. Supporting people in the criminal justice system. SB 27 allows people who committed minor crimes and are deemed unfit to stand trial to be enrolled in CARE court.
While these amendments won’t address all of the flaws in the CARE court program, they reflect the continuous evolution of laws to address some of the most complex challenges we face in mental health care.
If you’re worried about a loved one with severe mental illness. You can contact your county behavioral health department— here’s a directory— to learn if CARE court might be appropriate and how to file a petition. Family members, behavioral health providers, first responders, and others (e.g., housemates) can initiate the process.
For a mental health crisis: Call or text 988 (Suicide & Crisis Lifeline), available 24/7. If someone is in imminent danger to themselves or others, call 911 or take them to the nearest emergency department.
It’s unclear whether any mandated care could have helped the Reiners, but their loss reminds us how much work remains. No system is perfect. CARE court’s success depends on adequate county resources, continually refining our laws, and our collective commitment to supporting people with mental illness and those who love them.
Bottom line
Have a wonderful holiday! We’ve covered a lot of ground with YLE CA since our first edition in August. And we have a lot of important and interesting ground ahead of us, thanks to your suggestions.
Coming up in the new year, I’m working on deep dives into a few topics you’ve asked about, including microplastics, e-bike safety, cannabis, and hepatitis C. If you’ve got questions about any of these topics for me, drop them in the comments or send me an email. I’ll be back with your public health news, winter virus reports, and vaccine updates on January 8.
For now, I’m taking the next week to be with family and friends—the kids are all home. Hope you can unplug, too. Thank you for being part of this learning community. Happy holidays, be well, and I’ll see you in 2026.
Love,
Matt
P.S. Some of you have asked if Your Local Epidemiologist can accept donations as part of your year-end giving. Yes, and I am so grateful for you! YLE is a fiscally sponsored project of Social Good Fund, a California nonprofit corporation and registered 501(c)(3) organization, Tax ID (EIN) 46-1323531.
You can make a tax-deductible donation online here.
If you need to send a paper check instead, mail it to Social Good Fund, PO Box 5473, Richmond, CA 94805-4021 and write "Your Local Epidemiologist" in the memo.
Dr. Matt Willis is the author of Your Local Epidemiologist in California. A California native, he’s served as a primary care physician, CDC epidemiologist, and public health officer for Marin County, where he guided the pandemic response. He lives in Marin with his wife, children, and their dogs Teddy and Ramona.
Re: Mental Health and CARE Courts. Behavioral health has always been a step-child in the healthcare system. Too many county MH departments are overwhelmed and attempting to manage the numbers of people who are struggling with severe mental illness (e.g., schizophrenia or bipolar disorders) along with those who are self-medicating and dealing with addiction. Your recommendation to refer to county systems is, unfortunately, the equivalent of "take two aspirin and call me in the morning". It will do little to address the underlying issues of lack of providers, ignorance about behavioral health, and fear and loathing of people who are different. I share this as a retired provider having worked in three counties in my 20 years of practice.
Thank you for all you do. I'm 70and have had all recommended vaccinations including Flu late October and Covid last week. I live alone so it's simply a matter of hygiene, avoiding low ventilation public spaces and a bit of luck for good measure.