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COVID-19 cases have been rising in the United States for weeks, with new variants contributing to the annual summer surge.
COVID-19 surveillance has been significantly scaled back since the U.S. public health emergency ended more than a year ago. Individual cases are no longer counted and severe outcomes are based on a representative sample of the population, but available data have consistently shown an upward trend.
Infections may be increasing in at least 38 states. data From the Centers for Disease Control and Prevention: Wastewater monitoring shows that virus activity is still relatively low, but hospitalizations and deaths are on the rise.
According to the CDC, COVID-19 infection levels are especially high in the West, and virus levels are also high in the South, where they have returned to February levels.
“Viruses tend to grow and survive better in warm, moist environments, which is consistent with what we’re seeing,” said Dr. Robert Hopkins, medical director of the National Foundation for Infectious Diseases, a nonprofit public health organization. “The South and West are experiencing hot, muggy conditions right now.”
The summer surge in infections is part of a familiar seasonal pattern, but experts warn the coronavirus remains unpredictable.
“I think it’s still a little early to tell what the pattern is,” Hopkins said, “We’re seeing a large percentage of the population infected in some way with the virus, we’re seeing a somewhat lower peak, and we’re seeing a winter surge as well as a summer surge. But I think it’s still a little early to tell whether that pattern is going to continue or whether it’s going to become a year-round illness or whether it’s going to be confined to certain times of the year.”
Data Source Wastewater ScanThis summer’s flood wave began several weeks earlier than last year’s and likely reached a similar peak level to last summer’s, according to the National Wastewater Monitoring Network, a Stanford University-based organization operated in partnership with Emory University.
“We don’t know yet whether this will be the peak level of this surge,” said Dr. Marlene Wolf, an assistant professor of environmental health at Emory University and program director for WastewaterSCAN.
“We’re always trying to understand what the potential seasonality of COVID-19 is and what the impact is of the emergence of new variants that could potentially cause spikes in infections that we see more regularly and more frequently than influenza or respiratory syncytial virus,” she said.
Over the past few months, the JN.1 virus variant that drove this winter’s spread has been overtaken by newer offshoots. These so-called FLiRT variants (an acronym that refers to the locations of amino acid mutations the virus has acquired) have some changes in places that help it evade the body’s immune response and some that help it become more transmissible. Two of them, KP.3 and KP.2, now account for more than half of new coronavirus cases in the United States, according to the CDC. data.
Because of manufacturing timelines, experts have to start making predictions now if they want a new vaccine by the fall.
Earlier this month, the FDA approved plans to update COVID-19 vaccines to make them more effective against the JN.1 strain of the coronavirus. But the agency has since updated its own recommendations. Vaccine manufacturers advice Given the “recent increase in the number of infections,” they would like to target the KP.2 strain if possible.
“JN.1 continues to evolve, making it somewhat difficult to choose a specific strain to use,” Dr. Jerry Weir, director of the Office of Viral Products in the Vaccines Research and Review Office in the FDA’s Center for Biologics Evaluation and Research, told the independent advisory committee ahead of its initial recommendation.
New vaccines (some of which could be switched to target KP.2) are expected to be available between mid-August and late September, long enough to provide protection during the winter respiratory virus season, but probably after this summer’s outbreak has subsided.
On Thursday, the CDC Recommendation It is recommended that everyone 6 months of age or older get the updated COVID-19 vaccine for the 2024-25 season. The recommendation reflects a vote by the agency’s independent advisory committee.
“It makes sense to vaccinate during periods when influenza and RSV infections are expected to occur because we want to reduce the overall incidence of disease,” Dr. Marcus Plescia, chief medical officer for the Association of State and Territorial Health Officials, told CNN.
Plescia said the protective effect of the COVID-19 vaccine is fading, and the timing of the shots is being prioritized to maximize protection during a time when the peak was higher and more sustained. Unlike the flu or respiratory syncytial virus, COVID-19 is constantly circulating and there is no time for pause.
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“There’s no time to rest,” he said. “Influenza and RSV can rest. You get through the season, that’s it, and you get ready for the next season.” [Covid] It’s just something that’s always there.”
According to the latest CDC data, influenza and respiratory syncytial virus levels remain low in the United States. updateBut vaccination rates for the three major respiratory viruses slumped over the winter, and CDC advisers are looking ahead to next season with discussions about influenza and respiratory syncytial virus vaccination recommendations.
On Wednesday, the CDC updated its recommendations for who should get the RSV vaccine, now recommending it for everyone age 75 and older, as well as people ages 60-74 who are at high risk for severe illness, in preparation for the upcoming respiratory virus season.
The change is intended to “simplify RSV vaccine decision-making for clinicians and the public,” the agency said. Said.
When it comes to infectious respiratory illnesses, “people need to remember there are things they can do to reduce their risk, and the main one is getting vaccinated,” Plescia said.
CNN’s Jen Christensen contributed to this report.
