By Brianna Abbott

The Covid-19 virus in the U.S. has largely faded from view. But it hasn't faded away.

National wastewater data shows low Covid-19 activity, according to the Centers for Disease Control and Prevention. The weekly reported Covid-19 deaths in April were slightly down compared with the same time a year earlier, federal data shows. Still, more than 300 Covid-19-related deaths were reported weekly as recently as mid-April.

Some infectious-disease specialists said they expect more cases this summer, as there have been somewhat regular summertime increases in the past. Others cautioned that Covid-19 can still surprise us, more than five years after it spurred a global pandemic that killed more than 1.2 million Americans.

"It is at our lowest levels it has been since the beginning of the pandemic," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota. "Our challenge is we don't know what that means for tomorrow."

The Trump administration on Tuesday released a more stringent set of guidelines for approving Covid-19 vaccines, requiring randomized controlled trials for new Covid-19 vaccines for many children and adults. The Food and Drug Administration expects it will be able to approve shots for adults older than 64 and other high-risk groups based on antibody testing.

The original Covid-19 shots were tested in large, randomized trials with placebos. The updated vaccines to match newer versions of the virus have been tested with antibody testing to ensure that they triggered an immune response.

As of May 10, the CDC projected that 70% of cases were caused by a version of the virus called LP. 8.1, an offshoot of the Omicron variant, which first appeared in late 2021, and is related to the JN.1 variant, which was the target of last season's booster shots. The LP. 8.1 version has picked up new mutations but hasn't yet led to an increase in cases or hospitalizations.

"Because there are so many people who have been vaccinated and infected, there is a high amount of immunity in the population," said Andrew Pekosz, director of the center for emerging viruses and infectious diseases at Johns Hopkins University. "I think we're also seeing that as a way to dampen the spread of the virus."

Surveillance and monitoring for changes to the virus is continuing, Pekosz said, but at much lower levels than before, so there is more reliance on modeling to suss out variant spread. Hospitalization and death data remain the most solid.

Covid-related hospitalizations in the U.S. are currently on the decline. There were some 1.3 hospitalizations per 100,000 people during the week ended with April 26, down from a winter peak of 4.2 per 100,000 people for the week ended Jan. 4, CDC data show. That rate is down from last winter, when hospitalization rates peaked at 7.8 per 100,000 people.

Most years, the U.S. has experienced additional Covid-19 waves in late spring or summer, in addition to wintertime surges. Last year, a summertime wave peaked at around the week of Aug. 31, with more than 1,300 deaths reported, CDC data shows.

Write to Brianna Abbott at brianna.abbott@wsj.com

(END) Dow Jones Newswires

May 20, 2025 17:11 ET (21:11 GMT)

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