Hospitals and emergency rooms could be forced to ration care by the end of this month, the Centers for Disease Control and Prevention warned Thursday, saying recent trends in COVID-19 and influenza are now on track to again strain America’s health care system. The new COVID variant JN.1 is making up an increasing share of cases, the CDC’s tracking shows.

“COVID-19 hospitalizations are rising quickly,” the agency said in its weekly update. “Since the summer, public health officials have been tracking a rise in multisystem inflammatory syndrome in children (MIS-C), which is caused by COVID-19. Influenza activity is growing in most parts of the country. RSV activity remains high in many areas.” 

The CDC has been urging people to get vaccinated as the peak of this year’s mix of three seasonal respiratory viruses — influenza, COVID-19 and RSV — is nearing.

In pediatric hospitals, the CDC says beds “are already nearly as full as they were this time last year” in some parts of the country. Data from emergency rooms published Wednesday tracked emergency room visits nearly doubling in school-age children last week.

The increase, driven largely by an acceleration in flu cases, follows weeks of largely plateauing emergency room figures nationwide ahead of Thanksgiving. 

Similar to this time last year, influenza emergency room visits are now outpacing COVID-19 for the first time in months across most age groups. Only in seniors do rates of COVID-19 remain many times higher than influenza.

Nursing homes have seen a steep rise in reported COVID-19 across recent weeks. In the Midwestern region spanning Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin, infections in nursing home residents have already topped rates seen at last year’s peak.

Is there a new COVID-19 variant? What to know about JN.1

A new COVID-19 variant called JN.1 has been driving a growing share of the latest wave of infections, officials estimate. 

The JN.1 lineage — a closely related descendant of the highly mutated BA.2.86 variant that scientists first warned about over the summer — was estimated last week in the CDC’s projections to make up as much as 29% of infections nationwide. That’s up from 8.8% at the end of November.

Health officials have been closely tracking the acceleration of BA.2.86 and its descendants, like JN.1, around the world in recent months. More than 4 in 10 test results from the CDC’s airport testing program for international travelers have turned up these strains.

A panel of experts convened by the World Health Organization concluded this month that JN.1’s changes were not steep enough to warrant a new revision to this season’s vaccines, but acknowledged early data suggesting these shots were less effective at neutralizing the strain.

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“CDC projects that JN.1 will continue to increase as a proportion of SARS-CoV-2 genomic sequences. It is currently the fastest-growing variant in the United States,” the CDC said last week.

“Right now, we do not know to what extent JN.1 may be contributing to these increases or possible increases through the rest of December like those seen in previous years,” they wrote.

However, so far the CDC had said that so far JN.1’s fast spread does not appear to be leading to any upticks in the severity posed by COVID-19. 

How big is the vaccination gap?

As COVID-19 and other respiratory viruses have accelerated in recent weeks, health officials say they have also been closely tracking an unprecedented drop in vaccinations this season.

Data from insurance claims suggest flu vaccinations in adults are around 8 million doses behind vaccination levels seen last year. The CDC’s survey data suggests flu shots in children are also down around 5 percentage points from the same time last year.

“Covering the missed volume is going to be very difficult or not possible,” vaccine manufacturers concluded at a recent stakeholder meeting with the CDC, according to a readout from the National Adult and Influenza Immunization Summit.

Health officials have also been urging providers to redouble their efforts to buoy COVID-19 vaccinations this year, especially for those most at-risk of severe disease like seniors.

In nursing homes, just a third of residents and less than 1 in 10 staff are vaccinated with this season’s COVID-19 shot. 

“We aren’t seeing the uptake in vaccines that we would like to see,” CDC Director Dr. Mandy Cohen told doctors at an American Medical Association event Tuesday.

Cohen also cited survey data on uptake of the RSV vaccinations, which were greenlighted for the first time this year in older adults. Around 16% of adults ages 60 and older say they have gotten the shot.

“We acknowledge that is too low and it is one of the reasons we wanted to have this conversation,” she said.