California Braces for Early Flu Season Due to Virus Mutation

California is preparing for an early and intense flu season this year, driven by low vaccination rates and recent mutations of the virus, according to health experts. The state has already reported its first flu death of the season in Los Angeles County, highlighting the urgency of the situation. With flu activity typically ramping up after the Christmas holidays, experts anticipate that the upcoming weeks could see a significant increase in cases.

Dr. Elizabeth Hudson, the regional physician chief of infectious diseases at Kaiser Permanente Southern California, stated, “We’re expecting an early and likely sharp start to the flu season.” This comes on the heels of last year’s particularly severe flu season, which raised concerns about the potential for consecutive years of high flu activity.

A notable factor in this year’s forecast is the emergence of the H3N2 subclade K, a mutant strain that has started to dominate in countries like Japan and the United Kingdom. Dr. Peter Chin-Hong, an infectious diseases specialist at UC San Francisco, expressed concern over the timing of this subvariant, which appeared after the formulation of this fall’s flu vaccine—decided in February. Hudson noted, “It looks like a bit of a mismatch between the seasonal flu vaccine strains and the new subvariant.”

While it remains uncertain how much the new strain will affect the flu vaccine’s effectiveness, data from the UK has shown that the current vaccines still provide substantial protection against hospitalization. Vaccinated children are reported to be 70% to 75% less likely to require hospital care, while adults have a 30% to 40% lower risk.

The Los Angeles County Department of Public Health emphasizes the importance of getting vaccinated. “Public Health strongly encourages everyone who has not received the flu vaccine yet this year to receive it now, especially before gathering with loved ones during the holidays,” they stated. This advice is crucial, as the flu vaccine, even if not a perfect match for circulating strains, can still offer protection against severe illness.

The situation is further complicated by declining vaccination rates. In the United States, only 49.2% of children had received a flu shot by late April, a drop from 53.4% the previous season. Among adults, the vaccination rate was 46.7%, slightly lower than the prior year. According to the CDC, “Flu vaccination levels have not rebounded to pre-pandemic levels.”

In Australia, where flu season typically serves as an indicator for the Northern Hemisphere, recent reports indicate a record season with over 410,000 confirmed cases, surpassing the previous high of 365,000. This trend raises concerns for health officials in California, as the country’s experience may foreshadow challenges ahead.

Japan is currently facing a surge in flu cases, prompting a national alert due to increasing hospitalizations, particularly among children and the elderly. As the flu spreads, Taiwanese health officials warn of a possible second peak in cases as early as December, coinciding with the Lunar New Year on February 17.

Experts recommend taking additional precautions, such as using antiviral medications like Tamiflu, particularly for vulnerable populations including young children and the elderly. Chin-Hong highlighted the importance of early diagnosis, stating that antiviral drugs are most effective when administered within one to two days of the onset of symptoms.

As the flu season unfolds, health authorities stress the significance of public awareness and proactive measures. Vaccination remains the first line of defense. “Vaccines save lives. The flu vaccine in particular saves lives,” Hudson affirmed, urging the community to remain vigilant as the flu season approaches.