While attention shifts to the new omicron variant, a familiar adversary is driving up coronavirus cases again in Kentucky, Gov Andy Beshear said Thursday.

The delta variant — which inflicted considerable suffering in recent months — is responsible for the new upswing in COVID-19 cases, the governor said. Kentucky surpassed 3,000 new virus cases on Wednesday for the first time since the start of October, he said.

“We are seeing cases escalate,” Beshear said at a news conference. “Now I hope that it is temporary. Or perhaps we will just be at a much larger plateau, where there are ups and there are downs.”

Later Thursday, the state reported 2,841 new virus cases and 40 more virus-related deaths, while the rate of Kentucky residents testing positive for COVID-19 increased to 9.2%. Kentucky’s death toll from the virus surpassed 11,000.

The latest increase in cases means long-beleaguered hospitals are receiving more patients. Virus-related hospitalizations across Kentucky were up about 11% in the past week, Beshear said.

The Democratic governor again implored unvaccinated Kentuckians to take the COVID-19 vaccine and for the vaccinated to get their booster shot when eligible. People also should wear masks when in indoor public places to combat the virus’s spread, he said.

Statewide, 60% of all Kentuckians have received at least one dose of a COVID-19 vaccine, while about 13% have received the booster shot, Beshear said.

Waning immunity among the vaccinated is a likely factor in the new increase in virus cases, he said.

On a daily basis, booster shots are outpacing new vaccinations in the state, he said.

From March 1 to Dec. 1 of this year, more than 80% of all COVID-19 cases and virus-related hospitalizations and deaths in Kentucky were among the partially vaccinated or unvaccinated.

As for omicron, the governor has said the new variant is a reason for concern but not for panic.

“Remember, breathe,” the governor said Thursday. “We don’t know if this one is going to be worse or not. We will have the information. And we have more tools than ever before.”

But the new variant shows the coronavirus is “not done with us,” he said.

“We can’t be done with it,” he added. “But we can win and we can protect each other.”

The omicron variant has not been detected in Kentucky. Dr. Steven Stack, Kentucky’s public health commissioner, said he is working with local health departments and labs to identify any suspected cases as quickly as possible.

“People should expect we will have (omicron) cases,” Beshear said.

Reflecting how little is known about omicron, the governor added: “We don’t necessarily know that this one will be harsher than delta, which has been really harsh.”

The U.S. recorded its first known omicron infection Wednesday, in a fully vaccinated person who returned to California from South Africa, where the variant was first identified. A second U.S. case was confirmed Thursday in Minnesota, involving a vaccinated man who had been in New York City.