The U.K. reported 53,495 new cases on Thursday – the highest single-day rise since July 17, British health officials said.

Hospitalizations in the U.K. are down 6.5% over the last week while deaths are down 3% over the last week, officials said.

Over 80% of the 12-and-over population is fully vaccinated.

Thirty-two cases of the omicron variant have been detected in the U.K.

-ABC News' Christine Theodorou

As omicron appears to be rapidly overtaking delta as the dominant variant of the novel coronavirus in South Africa, a scientist warned Thursday that the new variant appears to be able to dodge some of the immunity from vaccines and previous infections.

Professor Anne von Gottberg, a clinical microbiologist at South Africa's National Institute for Communicable Diseases, told reporters during an online press briefing that omicron may not be more contagious or virulent than delta, but early data indicates previous infection does not provide protection against omicron as it seems to do with delta.

"We believe that omicron is widespread in the country," von Gottberg said.

South Africa and Botswana were the first countries to identify the omicron variant last month. Since then, South Africa has reported a total of 172 confirmed cases and Botswana has reported 19.

Over the past week, Southern Africa has recorded a spike in COVID-19 infections, hospitalizations and deaths, mostly driven by South Africa, where scientists believe omicron is rapidly becoming the dominant variant.

"It does look like there is a predominance of omicron throughout the country," von Gottberg said. "Almost 80% of specimens being sequenced in November are omicron. So we believe, truly, there is a link in the increase in cases with omicron variant."

The Minnesota Department of Health said a Minnesota resident with recent travel history to New York City has become the state's first confirmed case of the omicron variant.

The adult male lives in Hennepin County and has been vaccinated.

After experiencing mild symptoms on Nov. 22, he was tested on Nov. 24. He no longer has symptoms.

He attended an anime convention at the Javits Center in Manhattan from Nov. 19 to Nov. 21. Anime NYC said it welcomed 53,000 fans. New York Gov. Kathy Hochul said the state is in touch with health officials in Minnesota and she encouraged any of the 53,000 attendees to get tested.

New York City Mayor Bill de Blasio said, "we should assume there is community spread of the variant in our city."

“Since the beginning of this pandemic, Minnesota’s nation-leading genome sequencing infrastructure and strong testing network have allowed the state to quickly track the COVID-19 virus and better understand its spread. Today, those tools detected a case of the Omicron variant in Minnesota," Gov. Tim Walz said in a statement. "This news is concerning, but it is not a surprise. We know that this virus is highly infectious and moves quickly throughout the world."

Unvaccinated people in Germany will be barred from most businesses, except for grocery stores and pharmacies, officials announced Thursday.

In Germany, shops and restaurants check vaccination status at entrances.

Nearly 69% of Germans are fully vaccinated. The country has reported several cases of the omicron variant.

-ABC News'  Joe Simonetti

Three cases of the omicron variant have been detected in Maryland, all among Baltimore area residents, Gov. Larry Hogan said.

One of these people, who is vaccinated, recently traveled to South Africa. The second case is someone in their household who is not vaccinated, Hogan said.

The third case is unrelated; this person, who is vaccinated, has no recent travel, Hogan said.

No one required hospitalization, he said.