Hospitalizations are rising, is the virus surging?

“The U.S. has experienced increases in COVID-19 during the last three summers, so it’s not surprising to see an uptick after a long period of declining rates,” CDC spokesperson Kathleen Conley said in an email.

Dr. Bernard Camins, medical director for infection prevention at the Mount Sinai Health System in New York City, said his hospital is seeing about 40 Covid patients a day, compared with about 10 per day earlier in the summer. 

“The good news is that we’re not seeing patients who are that sick,” he said. About 5% of the patients hospitalized for Covid are sick enough to need intensive care treatment, which is a “very small number,” he said. 

Camins said there’s been no change in the people who are most at risk for severe illness: older adults, those with medical conditions such as diabetes or heart or lung disease, and those who are immunocompromised. 

Hospitalization rates have typically been higher in unvaccinated people, Conley said, though most Americans have some form of immunity from past infection, vaccination or both.

There also hasn’t been an increase in Covid-related deaths, which tends to lag behind a rise in hospitalizations. But deaths might not go up if people get prompt treatment with Paxlovid or other antivirals, Camins said. 

Bill Hanage, an associate professor of epidemiology at the Harvard T. H. Chan School of Public Health, said that people are more likely to get Covid now than they were earlier this summer.

But, he said, “you’re still not hugely likely to be getting it.”  

“And if you do, and you are vaccinated, then your chance of being seriously ill is very slim indeed,” Hanage added.

What the wastewater says

Covid cases are more difficult to track now than they were earlier in the pandemic. When the public health emergency ended in May, states were no longer required to report the data. What’s more, many people also use home tests, which aren’t reported to the government. 

In lieu of case counts, wastewater surveillance data is a good way to figure out how many people have Covid. “We’re learning that there’s a correlation between wastewater test results and hospitalizations,” Camins said. Wastewater is also increasingly being used to track other infectious diseases.

Marlene Wolfe, project director for WastewaterSCAN, which monitors 171 different wastewater treatment sites across 34 states, said there’s been an upward trend of virus concentrations in the past three weeks. It’s happening in most areas of the country, she said, but particularly the West, the Midwest and the Northeast. The concentrations of the virus are still relatively low, however, compared to earlier points in the pandemic.

“We do see this kind of upward trend that is happening, but we want to be cautious about waiting to see where that goes,” she said. “It’s not a sharp upturn and the concentrations are still on the lower side.”

Wolfe said she isn’t planning on making any particular lifestyle changes based on the data she is seeing. However, she noted that they are also tracking many other viruses in wastewater, which is turning out to be a good way to understand what’s happening with flu, respiratory syncytial virus or RSV, mpox and others.

“I personally look at that data also to help me make informed decisions about protecting myself from a lot of different diseases, doing things like getting a flu shot,” she said. 

Crowds, hot weather and summer travel

It’s not clear exactly why Covid cases are going up, but a number of factors could be at play. 

“It could be being driven a little bit by folks being indoors when it’s been really, really hot in various parts of the country,” Hanage said. 

And an increase in travel and crowds could be another reason for the spread of the virus. Summer peaks have occurred in previous years, Camins said. 

“I think it may be that it’s just a culmination of a lot of activity where people are gathered together,” he said. “Places are crowded, and so it just makes the virus easier to spread.”

The uptick in cases doesn’t necessarily mean the U.S. is at the beginning of a fall surge, experts said. 

“We expect that to start happening really towards October or November,” Hanage said.

Experts aren’t recommending that people necessarily change their behavior based on the new information. “If you really are at high risk, and you’re going to be in a crowded area, especially with the numbers going up, you should consider wearing a more protective mask, such as a KN95 or N95,” Camins said. 

People with symptoms or who think they’ve been exposed to the virus should take a Covid test and follow the CDC guidelines, he said. 

“If you know that you’re infected, then you should stay home with a mask on and stay away from people,” Camins said. “Or if you were exposed, to go get tested — those recommendations have not been changed.”

Updated boosters that target the XBB.1.5 subvariant strain are expected to be available in the fall. The FDA asked drugmakers to update the boosters to target that strain in June, and on Tuesday, Pfizer said its booster could be authorized by the end of this month. 

“Vaccination remains the safest strategy for avoiding hospitalizations, long-term health outcomes, and death,” Conley said.

“The fact that we’re seeing upticks around here and there is not at all surprising,” Hanage said. The virus isn’t going away, and we can do things to protect ourselves. Let’s make sure we do.”Follow NBC HEALTH on Twitter & Facebook.