KP.2 is now the dominant COVID variant. Experts say US may see a summer increase in cases

Over the past few months, JN.1 has been the dominant COVID-19 variant in the United States, accounting for the majority of cases. However, a new variant has taken over and could lead to an increase in cases this summer.

KP.2, which is an offshoot of the omicron variant, currently accounts for about 28.2% of COVID cases, after accounting for just 1.4% of cases in mid-March, according to data from the Centers for Disease and Prevention .

For the past four years, the United States has experienced summer waves of COVID and this summer could also bring an increase in cases, although not as severe as previous seasons.

“We’ve had four consecutive surges in COVID in the summers over the last four years,” Dr. Peter Chin-Hong, a professor of medicine and infectious disease expert at the University of California, San Francisco, told ABC ( UCSF). News. “We expect an increase this summer as well, but it probably won’t be significant and it probably won’t be as deep as in winter.”

Chin-Hong said he would characterize the increase as a “swell” rather than a “wave” or “surge.”

“Like when you’re at the beach and you see the swell coming,” he explained. “It’s not like a tsunami, it’s not like a huge crashing wave, it’s just kind of like a little swell. But the swell means some people are going to get sick.”

Early data indicates that KP.2 has more mutations on the spike protein than JN.1, which the virus uses to attach to and infect cells, which could potentially make KP.2 more infectious.

“The ability of the virus to evolve is anticipated, and that is something we have prepared for as part of our ongoing public health response,” said Dr. John Brownstein, an epidemiologist and chief innovation officer at the Boston Children’s Hospital and ABC News contributor. “Given the seasonal trends seen with COVID-19, an uptick in cases could be anticipated this summer, making continued surveillance and vaccination efforts all the more essential.”

Experts say there is no clear evidence that KP.2 — which some scientists have dubbed “FLiRT” on social media but which is not an official name used by the CDC or the World Health Organization health – causes more severe illness or is more deadly than previous variants.

Although more studies are needed to see whether KP.2 is better at evading current vaccines than other variants, Chin-Hong said his experience at the UCSF hospital over the past few weeks seems to indicate that vaccines continue to offer good protection.

He said the only common factor among all patients hospitalized at UCSF with severe COVID is that none of them received the updated COVID vaccine rolling out in fall 2023.

“If you haven’t yet, go ahead and get it,” Chin-Hong said.

He added that it is especially important for those who are immunocompromised or more susceptible to severe illness, such as those aged 65 and older, to get vaccinated.

COVID hospitalizations have not increased in the United States, which is an important milestone for the country.

At the end of April, the latest week for which data is available, the United States recorded 5,615 weekly COVID-related hospitalizations. For comparison, there were more than 150,000 weekly admissions at the peak of the omicron variant circulating in early 2022.

Experts say the United States is in a much better position to fight COVID than at the start of the pandemic and that the new variants remind us to stay vigilant, but not panic.

“We have to remember that this virus has become part of the respiratory system that we deal with every year, just like the flu, and, just like the flu, we try to stay one step ahead to prepare for any possible outbreak or to understand the extent to which vaccines are suitable,” he added. “, Brownstein said. “This is simple public health surveillance. It’s important to stay up to date on vaccines, stay vigilant and stay home when sick.”