ATLANTA – COVID-19 degrees are the lowest the United States has ever seen, yet a new generation of variants of the virus is making a comeback threatening to interrupt the downward trend as the country heads into summer.
According to data from the Centers for Disease Control and Prevention, KP. 2, one of the so-called FLiRT variants, has overtaken JN. 1 and become the dominant variant of the coronavirus in the United States. Data through May 11 shows it is guilty of more than a quarter of cases in the country, nearly twice as many as JN. 1. A similar variant, KP. 1. 1, is to blame for about 7% of cases, according to CDC data.
The FLiRT variants are offshoots of the JN. 1 variant, all of which are part of the Omicron family, which caused this winter’s wave. The acronym of the designation refers to the locations of amino acid mutations that the virus has detected, some of which help it evade the body’s immune reaction and some that help it become more transmissible.
COVID-19 variants are “cumulative mutations that do one of two things: either cause antibodies accumulated from vaccination or infection to no longer bind to the virus (we call this immunity evasion) or increase the strength with which viruses bind to cells,” said Dr. Andy Pekosz. virologist at the Johns Hopkins Bloomberg School of Public Health.
It’s become a familiar trend for how the virus that causes COVID-19 continues to evolve, however, experts say we still don’t know enough to expect precisely where the next adjustments will occur or how the virus will spread.
Mutations in the FLiRT variants make increased transmissibility (and an imaginable summer wave) a genuine threat. COVID-19 is settling into some seasonal patterns, which included a summer surge in previous years, but the precise point of threat for this year is unclear. .
“We’ve had diversifications in the afterlife that started quite strongly and then didn’t take over. These subvariants may gradually become dominant, or they may succeed in 20-40% of cases and then stay there. We just have to “Look,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University. “The virus continues to lead. He’ll tell us what he’s going to do. All our crystal balls are cloudy. “
COVID-19 surveillance has declined especially since the end of the U. S. public health emergency a year ago, also adding to uncertainty. But the available data is consistent. For now, wastewater surveillance suggests that viral activity is very low and declining in all parts of the country, and that hospitalization rates from COVID-19 remain incredibly low.
“We’ve learned from labs that FLiRT variants appear, so far, to be as transmissible as other Omicron subvariants, meaning they’re highly contagious. But they don’t seem to produce more severe disease or any type of disease that’s unique to the clinical presentation,” Schaffner said.
As of May 1, the requirement for all hospitals to report their knowledge of COVID-19 to the federal government expired. But Vanderbilt University Schaffner Medical Center is part of a CDC-run surveillance network that continues to track trends across a sample of hospitals. covering about 10 percent of the U. S. population. U. S. COVID-19 hospitalization rates have risen from about eight new admissions per 100,000 people in the first week of the year to about one new admission per 100,000 people at the end of April, the knowledge demonstrated.
While FLiRT variants pose some threat this summer, experts remain focused on what could happen in the fall.
“If I had to predict, I’d say it could lead to a few more cases, a small increase this summer. But it will be a question of which variant will be provided in the fall,” Pekosz said. probably in the fall we deserve to expect a surge in COVID cases. And if we have a variant that has a lot of those mutations that evade immunity, then the chance of a bigger surge in the fall is greater. “
Fall and winter pose a greater threat because of the immunity that has developed within the population, he explained.
“The virus now needs more situations to transmit, and those greater situations to transmit will likely occur in the fall, when the weather cools down, other people spend more time indoors, and are more likely to be in settings where transmission of the respiratory virus occurs more effectively. “
The research published Wednesday in the medical journal JAMA is a reminder of the burden COVID-19 continues to weigh on the United States. This winter, although hospitalization rates from COVID-19 were much lower than in previous years, it is still deadlier than the flu. A study of thousands of hospitalized patients found that 5. 7% of COVID-19 patients died, compared to 4. 2% of those hospitalized with the flu. In other words, COVID-19 carries about a 35% higher risk of death. death than the flu.
People who received the last COVID-19 vaccine last fall would likely still have some coverage against newer variants; This vaccine targeted another strain that has yet to be found to be just as effective as JN. 1, and experts say some of those that gain advantages may also improve their FLiRT parents. People who have had a recent infection – especially since the beginning of the year – when JN. 1 is the main – would possibly also get advantages from some coverage. But immunity wanes over time.
For now, experts say, the threat remains low.