The new COVID-19 subvariants, collectively nicknamed FLiRT, are gaining traction across the U.S., particularly fueling a rise in cases in Los Angeles County and increased viral levels in California wastewater. FLiRT variants—officially named KP.3, KP.2, and KP.1.1—now account for about 63% of COVID specimens nationwide, up from 45% just a month ago, according to the U.S. Centers for Disease Control and Prevention (CDC).
This surge has arrived earlier and is driven by more transmissible strains than seen previously. Despite this rise, it remains unclear how severe the situation will become, though experts anticipate having a clearer picture by July 4th.
In California, the resurgence is stark. The state’s wastewater data, an important indicator of viral spread, shows a sharp increase in COVID levels since early May. While nationwide trends indicate a slower rise, California’s viral activity in wastewater is nearing the peak observed last year. Notably, Santa Clara County is seeing high levels across Silicon Valley, and while L.A. County’s COVID levels in wastewater have stabilized after an increase last month, they remain elevated compared to the winter of 2022-2023.
Reported COVID-19 cases in L.A. County continue to rise, reaching an average of 154 cases per day by mid-June, a significant increase from 121 the previous week. However, case counts likely underrepresent the true numbers, as fewer people test when sick, especially using at-home kits. Hospitalizations are also up, with an average of 138 people per day hospitalized with COVID in the same period, up from 126 the previous week.
In the broader context of California, 7.5% of COVID tests returned positive results by mid-June, more than double the positivity rate from a month prior. The year of 2023 saw a peak of 13.1% positivity at the end of August, which the state is already on track to approach.
As the virus continues to circulate, health officials are advising the public to stay vigilant, particularly older adults and those with weakened immune systems. The California Department of Public Health is urging these groups to stay updated on vaccinations, seek treatment if infected, and consider precautions like masking in crowded indoor spaces and increasing ventilation.
In response to the rise of the FLiRT subvariants, the U.S. Food and Drug Administration (FDA) issued new guidance in June for vaccine manufacturers to prepare updated shots targeting the KP.2 variant for the fall. This updated recommendation, designed to better match circulating strains, is aimed at enhancing immunity through the late autumn and winter seasons.
Experts stress the importance of vaccinations, particularly for vulnerable populations. Despite the complexities in COVID vaccine development, federal officials emphasize that receiving either the mRNA vaccines (Pfizer or Moderna) or the protein-based Novavax vaccine will offer significant protection. Doctors remind the public that COVID-19 remains a persistent threat, especially for older adults and those who haven’t kept up with their vaccinations.
Looking ahead, while the current surge is concerning, public health officials hope that this year’s vaccine will be available earlier than last year’s, facilitating a smoother rollout and offering better protection against the evolving virus.
