The Northeast is reemerging as a COVID-19 hot spot. Here’s what that means for Connecticut.

A year after an initial wave of COVID-19 that devastated Connecticut and other northeastern states, the region again stands as the hot spot for coronavirus in the United States.

Of the eight states with the highest level of new COVID-19 cases per capita over the past week, seven are in the northeastern or mid-Atlantic region — including Connecticut, which ranks sixth as of Tuesday. Of the eight states with the highest number of current coronavirus hospitalizations per capita, six are in the Northeast or mid-Atlantic.

Here is what to know.

What’s happening in Connecticut?

As numbers have declined steadily in other parts of the country, Connecticut has seen an increase in COVID-19 cases and positivity rate in recent weeks, while its hospitalizations due to the disease have plateaued.

The state’s numbers remain far lower than they were both during its initial surge last spring and during its second wave this past fall and winter, but they appear to be trending in the wrong direction.

What is causing this trend?

One potential culprit, experts say, is the B117 variant, which is more infectious than other strains and accounted for about 36% of Connecticut’s cases as of March 6, according to Yale School of Public Health researchers.

“The B117 variant seems to have sort of settled here in Connecticut,” said Dr. David Banach, an epidemiologist at UConn Health. “So that’s playing into it, and it’s sort of being countered by our vaccine success.”

Though B117 has been detected across the United States, it has been particularly common in the Northeast — and specifically in Connecticut, which has more confirmed cases per capita than any other state, according to data from the U.S. Centers for Disease Control and Prevention.

Why is B117 prominent here?

Mark Adams, deputy director of The Jackson Laboratory in Farmington, said the Northeast may have been particularly susceptible to B117 because of travel from the United Kingdom, where the variant originated.

“There were more [introductions of B117] in the Northeast because there were more travelers from the UK in November and December,” Adams said. “So multiple seeding events that then had time to spread.”

What about other variants?

The good news, Adams said, is that the share of B117 cases out of Connecticut’s total does not seem to be increasing rapidly. The bad news, he said, is that B117 has stabilized in part due to the introduction of other variants, particularly one first detected in New York.

“It’s coming up in frequency,” Adams said of the New York variant. “The numbers are small, but somewhere between 10 and 25%, so it’s not insignificant.”

That variant may help explain why New York currently has higher levels of COVID-19 cases and hospitalizations than any other state.

Josh Geballe, Connecticut’s chief operating officer, said Tuesday that the state had identified 45 cases of the New York variant so far. The state has also identified seven cases of the strain first detected in South Africa and one case of the strain first found in Brazil, though Adams said those don’t appear to be spreading significantly.

What impact has easing restrictions had?

Experts say variants aren’t the only explanation for COVID-19 numbers ticking upward in the Northeast. Adams noted that Connecticut has recently eased pandemic-related restrictions, signaling to residents that it was safe to congregate.

“This is coming at a time when some restrictions have been lifted and there is more interaction among people,” Adams said. “That’s certainly a way to get more cases.”

Keith Grant, senior system director of infection prevention at Hartford HealthCare, said he supports the decision to ease restrictions but wouldn’t be surprised if doing so caused increased transmission.

“We’re literally telling people there are things that they used to be doing to keep themselves safe that they no longer need to do,” he said. “There’s obviously going to be some fallout from that.”

Vaccination has made a difference

Despite recent trends, experts say Connecticut has likely benefited from its rapid vaccine rollout. About 31% of residents have received at least one vaccine dose, including more than 75% of those 65 or older. Max Reiss, a spokesperson for Gov. Ned Lamont noted that cases and deaths have declined among the groups that are most likely to be vaccinated.

“What we’re continuing to see is those who are getting sick are younger, and their likelihood of severe infection and complications remains low,” Reiss said.

But with less than a third of the state’s population vaccinated, COVID-19 still has ample opportunity to spread. Experts say the coronavirus is not likely to diminish fully before a given population reaches “herd immunity” with at least 70-80% of its residents having immunity against it.

The recent uptick in cases, Grant said, is a reminder that the process of vanquishing COVID-19 for good may be bumpy.

“I don’t expect this to be a smooth journey all the way down,” Grant said. “I don’t think it’s going to be a steady process.”

Alex Putterman can be reached at aputterman@courant.com.