The FLiRT variants of COVID-19, known as KP.3, KP.2, and KP.1.1, are on the rise across the country, leading to an increase in cases in Los Angeles County and higher levels of the virus in California wastewater. This resurgence is earlier than expected and is driven by more contagious strains than those seen in previous summers.
The U.S. Centers for Disease Control and Prevention reports that the FLiRT subvariants now make up 62.9% of specimens nationwide, up from 45.3% a month ago. These variants are more transmissible than the dominant strain from the winter, JN.1. California is among the 15 states with high levels of coronavirus in sewage, along with other states in the West, South, and New England regions.
Wastewater viral activity levels in California have increased sharply since early May, with levels near the peak seen last summer. In Santa Clara County, levels are high across Silicon Valley, while in L.A. County, levels have remained stable after a slight rise last month. Reported COVID-19 cases are increasing, with an average of 154 per day in L.A. County, up from 121 the previous week.
The percentage of positive COVID tests in California has also risen, reaching 7.5% for the week ending June 17, compared to 3.1% a month ago. The California Department of Public Health has updated its guidance for older adults, urging them to stay up to date on vaccines and take extra precautions.
The U.S. Food and Drug Administration has advised vaccine manufacturers to design this fall’s vaccine formula against the KP.2 subvariant, rather than the JN.1 strain. The mRNA-based vaccines from Pfizer and Moderna will be able to produce shots for KP.2, while the protein-based vaccine from Novavax will remain designed against JN.1. Federal officials hope to make the COVID vaccine available earlier this year to ensure protection for the upcoming season.
Despite the availability of vaccines, doctors emphasize the importance of continued vigilance against COVID-19, especially for older and immunocompromised individuals. The virus is still a threat, with about 45,000 deaths reported nationally since October. As the situation evolves, staying informed and following public health guidelines remain crucial in the ongoing battle against the pandemic.