New COVID-19 subvariants, collectively known as FLiRT, are continuing to increase their dominance across the country, leading to an increase in cases in Los Angeles County and increased coronavirus levels in California wastewater.
Taken together, these data point to a resurgence of the coronavirus in the Golden State — which, while not entirely unexpected given previous pandemic-era summer trends, is coming earlier and with more transmissible strains than previously seen Strain driven.
However, it’s unclear how bad the coronavirus situation might get this summer. Doctors say we may have a better feel by the Fourth of July about how the rest of the season will play out.
The Centers for Disease Control and Prevention estimates that the FLiRT subvariants, formally known as KP.3, KP.2 and KP.1.1, accounted for a combined 62.9% of samples nationwide in the two weeks ending Saturday. This is up from 45.3% a month ago.
Experts say the new subvariant is more contagious than the dominant winter subvariant, JN.1.
According to the Centers for Disease Control and Prevention (CDC), California is now one of 15 states with high or very high levels of the coronavirus in sewage. These states are generally located in the West and South as well as New England. In addition to California, there are Alaska, Colorado, Connecticut, Florida, Hawaii, Idaho, Missouri, Nevada, New Hampshire, New Mexico, Tennessee, Texas, and Utah state and Wyoming.
Coronavirus levels in California’s wastewater have increased sharply overall since early May, contrasting with national trends that show a slower rise. California’s latest weekly wastewater virus activity levels are close to last summer’s peak.
In Santa Clara County, Northern California’s most populous county, wastewater concentrations are high across a swath of Silicon Valley from San Jose to Palo Alto.
Coronavirus levels in Los Angeles County wastewater remain generally stable after rising last month. In the week ending June 8 (the latest data available), sewage levels were 15% of the 2022-23 winter peak, up from 13% the previous week but down slightly from 16% the previous week. It peaked late in the season last summer, when sewage levels reached 38% of their peak levels in winter 2022-23.
However, reported COVID-19 cases are still increasing. Los Angeles County reported an average of 154 cases per day in the seven days ending June 16, up from 121 the previous week. The number of reported cases is an underestimation because they only indicate tests performed at health facilities and do not include home testing. They also don’t reflect the far smaller number of people getting tested for coronavirus when they’re sick.
The average number of daily coronavirus infections in Los Angeles County hospitals has also increased. There were an average of 138 cases per day in the week ending June 15, up from 126 the week before.
The number of COVID-19 deaths remained stable in the week ending May 28, averaging less than one per day.
The rate of positive coronavirus tests at California medical facilities continues to rise. In the week ending June 17, the rate of positive coronavirus tests across the state was 7.5%, up from 3.1% a month ago. Last summer’s peak was 13.1%, recorded in late August.
The California Department of Public Health updated guidance for older adults in June, “especially those with weakened immune systems.” Officials urge seniors to get vaccinated promptly, seek medical treatment if infected with the coronavirus, and consider taking additional precautions such as wearing masks in crowded indoor areas, opening doors and windows to increase ventilation, staying away from sick people, and washing hands frequently. Cover your mouth and nose with your hands, and cover coughs and sneezes.
Some of the coronavirus tracking data increased as the U.S. Food and Drug Administration (FDA) issued new recommendations to vaccine manufacturers in mid-June. In a June 13 statement, the agency urged manufacturers to develop vaccine formulations this fall that target KP.2, one of the FLiRT subvariants, rather than its parent JN.1, if feasible.
The new recommendations reverse guidance from a week ago, when the agency suggested the vaccine was designed to target JN.1.
“This change is intended to ensure that COVID-19 vaccines (2024-2025 formulations) more closely match circulating strains of SARS-CoV-2,” the FDA said in a statement, referring to the official name of the COVID-19 virus.
Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a report that by this fall, the circulating new coronavirus subvariant “may be closer to KP.2 than JN.1.” .
The KP.2 vaccine will be produced this fall by an mRNA-based vaccine produced by Pfizer and Moderna. But Marks said the protein-based vaccine made by Novavax will still be designed to target JN.1 because production of the mRNA vaccine can be done more quickly.
“When you make a protein-based vaccine versus an mRNA vaccine, there’s a difference in what you can do in terms of the agility to respond to what’s going to happen,” Marks said. Still, the differences between vaccines designed against the newer KP.2 subvariant and the older JN.1 subvariant may not result in “that big of a difference.”
“We don’t have any preference,” Marks said, in recommending the Pfizer or Moderna vaccines over Novavax. “The best vaccine going into this fall is the vaccine that goes in the arm.”
Marks said a vaccine designed to target KP.2 “may provide a little benefit” over one designed to target JN.1. “By essentially using the latest updates, we hope to provide protective immunity that lasts longer,” Marks said, into late fall and winter.
“It’s like trying to give people the biggest advantage, right? The extra hundredth of a second you win [a race] With,” Max said. “But I think the most important thing for people to know is that either one of these is really good, either way.”
Federal officials have expressed hope that a COVID-19 vaccine will be available earlier this year than 2023. You can do the same if you like.
Doctors say COVID-19 remains a disease to be protected against. About 45,000 COVID-19 deaths have been reported across the country since Oct. 1, and doctors say those most at risk are older adults and immunocompromised people who are not up to date on vaccinations.
“It doesn’t just disappear into the night. It lingers,” Marks said.
