Early Start to Flu Season Raises Concerns
This year’s flu season began unexpectedly early and in a surprising region, according to health authorities.
The early onset has prompted local officials to recommend that people get their flu vaccinations as soon as possible.
In Los Angeles County, flu cases started to rise in September, which is notably earlier than the usual peak around early November, Dr. Dawn Terashita explained to The Times on Wednesday.
Dr. Terashita, who is the associate director of the Acute Communicable Disease Control Program at the Los Angeles County Department of Public Health, mentioned that this early activity isn’t shocking since the flu is known for being “very unpredictable” due to its mutating nature.
Another unusual aspect is that the flu season kicked off in the Western states this year.
Typically, flu season starts in the South and then spreads northward, noted Dr. Elizabeth Hudson, who is the regional chief of infectious diseases at Kaiser Permanente Southern California.
Terashita stated that it’s still too early to ascertain why this pattern has emerged.
Given the early surge, Hudson mentioned that many individuals might be caught off guard, as some haven’t had the opportunity to vaccinate, or they’ve only recently received the vaccine, meaning they haven’t yet built up adequate immunity.
The flu season in the county began on September 28, but Terashita pointed out that this early start does not necessarily indicate a more severe season overall.
The positivity rate for flu tests has been high in the San Francisco Bay Area and moderate in Southern California and the Sacramento Valley. However, flu-related hospital admissions throughout California remain low, with 34 deaths attributed to the flu reported this year by the state Department of Public Health.
Last week, San Francisco confirmed its first flu death of the season, while there have been no recorded influenza deaths in Los Angeles County yet, according to Terashita. She noted that last season, the county had a relatively low total of 126 flu deaths.
Kaiser has reported an increase in outpatient visits related to the flu, but hospitalization rates have not yet increased. Hudson anticipates that these rates could rise in the upcoming weeks if current trends continue.
Health officials emphasize that getting vaccinated is the best protection against the flu and are strongly encouraging people to get their shots soon.
Dr. Peter Chin-Hong, an infectious-disease expert at UC San Francisco, advised that individuals should aim for vaccination ideally before mid-October. For most people, the standard flu shot is sufficient, although there are alternatives like a nasal spray—suitable for almost anyone who fears needles—and higher-dosage shots for the elderly.
The current H3N2 subclade K variant is similar to last year’s strain and is included in this year’s vaccine, which eases concerns about a significant mismatch between the vaccine and circulating strains, according to Chin-Hong.
He stated, “The ball is in our court because vaccination behavior drives how we tackle the flu. This year we have less excuse because the flu vaccine is generally well-matched to what has been circulating.”
According to Terashita, the most severe flu season in recent memory for Los Angeles County was during the 2009 pandemic when the H1N1 virus caused considerable hospitalizations and fatalities worldwide.
During the COVID-19 pandemic, flu cases nearly vanished, but as social gatherings resumed and restrictions lessened, the county saw increases in flu cases in 2024 and 2025.
“We’re just watching and waiting right now,” Terashita said regarding the potential severity of the season. “But it’s a good reminder for everyone that getting vaccinated is a very effective way to protect yourself.”
