COVID-19 metrics in the U.S. fell slightly for the week ending Aug. 24, indicating the nation's summer wave may be slowing.
In terms of the sheer number of infections, experts estimate this summer's wave as the largest summer spike since the pandemic began, though hospitalizations have remained far below levels seen in previous surges.
Test positivity was 17% for the week ending Aug. 24, down 0.8% from the week prior. In the same week, COVID accounted for 2.5% of emergency departments, marking a nearly 4% decline from the previous week.
Despite early signs of decline, wastewater data — an early indicator of whether trends are increasing or decreasing — shows virus levels remain "very high" across the country.
Three more updates:
Vaccines: On Aug. 30, the FDA cleared Novovax's updated COVID-19 vaccine for use in individuals aged 12 and older. The monovalent, protein-based shots are an alternative to mRNA-based shots from Moderna and Pfizer. The updated formulation from Novovax targets JN.1, the omicron subvariant that dominated last winter and parent strain of currently circulating strains. A week earlier, the FDA signed off on updated vaccines from Pfizer and Moderna, which target KP.2, an offshoot of JN.1.
CDC estimates indicate KP.2's sister strains KP.3.1 1 and KP.2.3 collectively made up nearly 57% as of Aug. 31.
What's ahead for 2024-25 virus season: The CDC estimates respiratory virus levels and peak hospitalizations will be similar to or slightly lower than the 2023-2024 season, a welcome prediction for hospitals after several consecutive virus seasons marked by significant capacity and resource strain. Experts predict a roughly 80% chance that the peak hospitalization burden for COVID-19, influenza and respiratory syncytial virus will be similar to or lower than last season at around 20 per 100,000 people.
New variant: XEC is the latest omicron subvariant on experts' radar. The strain, a recombination of two lesser discussed subvariants KS. 1.1 and KP.3.3, has been detected in the U.S., though is not yet tracked by the CDC since it accounts for less than 1% of cases, experts told the Los Angeles Times.
The subvariant was first detected in Germany and "is just getting started now around the world and here," said Eric Topol, MD, PhD, director of the Scripps Research Institute in San Diego. "And that's going to take many weeks, a couple months, before it really takes hold and starters to cause a wave."
The emergence of a new COVID-19 variant with increased ability to evade immunity is one factor that could fuel a higher burden of severe disease this virus season, though experts say XEC isn't markedly different from strains that are currently circulating.
"But this is a little different, and it does seem to be showing what we call a growth advantage" over the dominant strains, Elizabeth Hudson, DO, regional chief of infectious diseases at Kaiser Permanente Southern California, told the Los Angeles Times.