• Posted June 25, 2024

Summer COVID Cases Are Rising Across America

As scorching summer temperatures drive Americans indoors and millions travel for vacations and family gatherings, COVID infections are again climbing, U.S. health officials warned Monday.

In evidence that suggests a COVID summer wave is underway, case counts are most likely increasing in 39 states and aren't declining anywhere in the country, new data from the U.S. Centers for Disease Control and Prevention shows.

While the CDC no longer tracks COVID cases, it still estimates spread of the virus using data on emergency department visits. Both COVID deaths and ED visits have risen in the last week, while hospitalizations climbed 25% from May 26 to June 1, according to the latest CDC data. 

"It looks like the summer wave is starting to begin,"Dr. Thomas Russo, chief of infectious diseases at the University at Buffalo Jacobs School of Medicine and Biomedical Sciences, told NBC News. 

Several new COVID variants are likely contributing to the summer spike in cases, Dr. Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, told NBC News.

"We're seeing the start of an uptick of infections that is coincident with new variants that are developing: KP.2 and KP.3 and LB.1. It does appear that those variants do have an advantage over the prior ones,"he added.

All three variants are descendants of JN.1, the version of the coronavirus that dominated this winter.

KP.2 became the dominant variant last month, and then KP.3 took over in early June, NBC News reported. Along with a third variant that shares the same key mutations, KP.1.1, the group now accounts for around 63% of all COVID infections in the United States, CDC data shows.

Meanwhile, LB.1 accounts for another 17.5% of COVID infections. Experts said its rapid growth indicates that it's likely to become dominant soon.

Still, "it's sort of the newest kid on the block,"Barouch said. "There's not much known about it."

A preprint study released this month, which hasn't yet been peer-reviewed, suggests LB.1 is more infectious and could be better at evading protection from vaccines or previous infections.

"Assuming that preliminary data is true, that it's more immune-evasive and that it's more infectious than KP.2 and KP.3, that's a winning formula to infect more people,"Russo noted.

Apart from variants, experts said cases will probably continue to rise as people retreat indoors to escape the heat and gather to celebrate the Fourth of July. 

Russo recommended that people who are vulnerable to infection and severe illness, or who are more likely to attend large parties or gatherings, consider getting the latest COVID vaccine. 

He added that a monoclonal antibody drug called Pemgarda has been available since April for immunocompromised people. The antiviral medication Paxlovid can also lower the likelihood of hospitalization or death.

As for young, healthy people, they can hold out for the updated COVID vaccines expected to arrive this fall, experts said.

This month, the U.S. Food and Drug Administration advised vaccine manufacturers to target the KP.2 variant. The CDC's Advisory Committee on Immunization Practices is set to meet Thursday to decide who should get those shots.

More information

The CDC has more on COVID vaccines.

SOURCES: U.S. Centers for Disease Control and Prevention, data, June 24, 2024; NBC News