California is enduring one of its most severe flu seasons in recent years, with more than 900 deaths recorded so far, including 15 children, according to the latest report from the California Department of Public Health (CDPH).
This surge has left health officials and residents alike grappling with the impact of a particularly aggressive influenza outbreak, compounded by declining vaccination rates and heightened concerns for vulnerable populations.
The most recent data, released on February 23, 2025, reveals a concerning increase in both adult and pediatric deaths. Of the 901 reported deaths, 701 were individuals aged 64 and older, a statistic in line with expectations, as older adults are typically at a higher risk of complications from the flu.
However, the report also highlighted the death toll among children, which has raised alarm bells across the state. In the week ending February 15, four more children died from the flu, pushing the seasonal pediatric death total to 15, a troubling figure given the rising numbers.
Dr. Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco, said, “We have to reset with the flu. Because with flu, it’s not just the very old, it’s also the very young. And they can do very poorly.”
This stark reminder echoes a troubling shift in the flu’s impact, with more children suffering from its effects, many of whom were not vaccinated.
One of the primary factors fueling this deadly flu season is a marked decline in vaccination rates, particularly among children.
Dr. Chin-Hong said, “In the world of vaccines, that’s like falling off a cliff.”
According to data from the Centers for Disease Control and Prevention (CDC), national vaccination rates among children between the ages of 6 months and 17 dropped from 58% in the 2020-21 flu season to around 45% by January 2025.
California mirrors this trend, with only 47.7% of children vaccinated as of late January, a steep drop from 53.7% the previous year.
The flu vaccine is strongly recommended by public health officials, with the CDC urging everyone 6 months and older to get vaccinated, ideally by the end of October, to ensure protection throughout the high-risk winter months.
However, the reality of low vaccination rates means that many Californians remain unprotected as the flu spreads aggressively through communities.
“The recent flu deaths among our youth are tragic and concerning,” Dr. Ankita Kadakia said, interim public health officer for San Diego County, where four teenagers, none of whom had received flu shots, tragically succumbed to the virus. “As we head into what historically is the peak of flu season, we must do everything we can to protect our children from this potentially deadly virus.”
The flu season this year has been particularly brutal, with the H1N1 and H3N2 strains circulating widely across the state.
H1N1, the same strain that caused the 2009 swine flu pandemic, is once again wreaking havoc. H3N2, known for causing more severe illness, is also contributing to the heightened mortality rate.
Dr. Chin-Hong said, “H3N2 is notorious for just causing more serious illness in general.”
Despite this, public health officials are cautiously optimistic that flu activity might be beginning to decline. For the week ending February 15, the rate of positive flu tests decreased by 3.4%, though the positivity rate remains elevated at 23.3%.
Dr. Chin-Hong said, “It’s not yet clear whether the downward trend will hold.” Flu season in the U.S. typically peaks between December and February but can extend well into spring, making it crucial for individuals to continue taking precautions.
“It’s not only the peak that we’re worried about,” Dr. Chin-Hong said. “It’s also the breadth of what’s happening this year.”
The flu season is far from over, and experts warn that the virus can circulate well into April and beyond, prolonging the strain on hospitals and healthcare systems.
The numbers are stark in comparison to previous flu seasons. By this time last year, roughly 500 people had died from the flu in California, with 600 reported the year before.
Dr. Chin-Hong remarked that the 900-plus death toll this season is the worst he’s seen in nearly a decade, underscoring the severity of this flu season and the toll it is taking on communities across the state.
As California enters the final stretch of flu season, health officials continue to stress the importance of vaccination.
“It’s never too late to get a flu shot,” Dr. Chin-Hong said. “Even if you haven’t gotten it yet, it’s still the best way to protect yourself and your loved ones from this dangerous virus.”