HV.1 dominates US COVID-19 cases

CDC data shows that for the week ending in Oct. 28, COVID-19 infections due to HV.1 totaled 25.2% of all COVID-19 cases in the United States. The EG.5 subvariant comprised the second-most cases.

According to Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center, HV.1 may be slightly better than EG.5 at evading prior immunity to COVID-19, but not enough to cause alarm.

"I would expect that it might be a slight increase in transmissibility or immune escape, which is why it appears to be dominating," he said. "Does it change any booster recommendations so far? Probably not."

Experts say the new COVID-19 vaccines, which were made to target the XBB.1.5 variant, should still offer cross-protection against the strains that are currently dominant in the United States.

Scott Roberts, an infectious disease specialist at Yale Medicine, said that while the vaccine isn't a "perfect match" for HV.1, "it's still a good match because it's still within the same family of variant."

Overall, COVID-19 admissions have been dropping in the United States for weeks. For the week ending in Oct. 21, there were just over 16,100 new COVID-19 hospital admissions, a 0.2% decline from the week before.

CDC also said it's separately monitoring another COVID-19 variant, JN.1, which was first detected in the United States in September. CDC said the strain is very similar to BA.2.86 and currently comprises less than 0.1% of cases. As a result, the agency said it's "too early to tell whether it will spread more widely."

COVID-19 vaccine effort gets off to slow start

Meanwhile, this fall's COVID-19 vaccination effort has gotten off to a slow start. According to a CDC survey, as of Oct. 14, just over 7% of adults and 2% of children have received a new COVID-19 vaccine. That includes just one in five people ages 75 or older and around 15% of those ages 65 to 74.

"I hope uptick increases, but I'm pretty pessimistic," Roberts said. "I don't think we'll hit anywhere near the levels we had last year."

A few things have hindered the vaccine rollout this fall. For example, this vaccine is the first that is part of the commercial market rather than being distributed and funded by the government.

While most insurers have agreed to cover COVID-19 vaccines completely, some didn't update their billing systems in time for appointments, meaning some people were told they needed to pay for their shots, which led to them canceling scheduled vaccinations. According to the Biden administration, that issue has been mostly resolved.

Vaccine shipments have also been delayed, leading some pharmacies to cancel appointments in September. Parents have also had difficulties finding appointments for children, who require smaller doses. Roberts added that some pediatricians' offices might not have the proper cold storage for the shots, or they may lack the freezer space. Others have either underestimated demand or aren't willing to pay for larger shipments.

"If people try and are unable to get their vaccine, then it's likely they'll never go back and try again," Barouch said.

Alongside logistical problems, many Americans are uninterested in getting another COVID-19 vaccine. According to CDC's survey, around 38% of adults said they won't choose the vaccine for themselves, and around the same percentage said they won't have their children immunized.

"The logistic complications certainly were not helpful, but I think that the low uptake is more than that," Barouch said. "The low uptake reflects that most of the public is no longer concerned about Covid."

"We can have the best vaccine in the world, we could have the best ability to access it in the world," said David Kimberlin, a pediatrician at the University of Alabama at Birmingham, "it's just going to sit on the shelf." (Carbajal, Becker's Clinical Leadership, 10/30 [1]; Carbajal, Becker's Clinical Leadership, 10/30 [2]; Bendix, NBC News, 10/27; Mandavilli, New York Times, 10/27)

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