Officials have identified cases of a new, potentially far-more-contagious strain of the novel coronavirus in more than 30 countries, including in the United States—and U.S. officials fear the new variant could worsen the country's already ballooning coronavirus epidemic.

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What's known about the new coronavirus variant—and where it's been detected in the US

Officials in Britain first announced the discovery of the new coronavirus variant on Dec. 8, 2020. During a news conference, United Kingdom Prime Minister Boris Johnson and England's CMO Chris Whitty said scientists identified the new strain—labeled B 1.1.7—through Public Health England's genomic surveillance.

Johnson at the time said scientists believed the new variant—which has about 20 mutations, including several that affect how the virus attaches to and infects cells in the body—is more infectious than the original version of the novel coronavirus. "There's no evidence that it causes more severe illness or higher mortality, but it does appear to be passed on significantly more easily," Johnson said. "Although there's considerable uncertainty, it may be up to 70% more transmissible than … the original version of the" virus.

And although Johnson in December announced stricter lockdown measures across Britain to prevent the spread of the coronavirus and its new variant in the wake of a significant surge in Covid-19 cases, the new variant has become the dominant strain of the novel coronavirus circulating in the United Kingdom, Axios' "Vitals" reports. In response, more than 40 countries have banned arrivals from the United Kingdom, and some other countries—including the United States—have imposed restrictions on travelers from some or all of the countries where the new variant has been detected.

Nonetheless, since Dec. 8, 2020, officials in the United States and at least 32 other countries have detected the new variant of the coronavirus. In the United States specifically, officials have identified cases the new variant in California, Colorado, and Florida. None of the Americans infected with the new variant had traveled recently, which suggests that the new variant is circulating throughout the country via community spread, officials said.

US officials worry new variant could worsen America's coronavirus epidemic

U.S. officials said they're not shocked the new variant has been identified in the United States, and they expect other states will report cases of the new coronavirus strain. According to "Vitals," experts anticipate the new variant will eventually become the dominant strain circulating in the United States, just as it has in the United Kingdom.

"Epidemiological models and Britain's experience indicate that, while only a few cases of the variant have been identified in the United States, it will likely become our dominant strain within a few months," Ashish Jha, a general internist and professor of global health at the Harvard T.H. Chan School of Public Health, and Robert Wachter, chair of the department of medicine at the University of California-San Francisco, wrote in an opinion piece published Sunday by the Washington Post. And Jha and Wachter warned that the new variant, which appears to be more easily transmitted, could worsen America's coronavirus epidemic.

"A more infectious virus means more cases, which means more hospitalizations and deaths," they wrote.

During an appearance on CNN's "State of the Union" on Sunday, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, urged people to take the new coronavirus variant "very seriously."

British officials have said they expect existing Covid-19 vaccines will be effective against the new variant of the virus, and Fauci said U.S. officials will be conducting their own studies to determine how effective recently authorized vaccines are against the new strain. "We're getting isolates of [the new variant], making combination of viruses, to be able to directly test, getting sera from people who we have vaccinated, and see if it still neutralizes this new strain," he said.

But even if the United States' authorized Covid-19 vaccines are effective against the new coronavirus variant, it will be many months until those vaccines are widely available in the country. In the meantime, Americans must continue to closely follow measures such as social distancing, mask wearing, and frequent hand washing to protect themselves and others against the coronavirus's spread, experts say.

Mercedes Carnethon, a professor of medicine at Northwestern University, during an appearance on MSNBC on Friday said public health officials must "reinforce[e] the basic messages that we know about how to stop the community transmission" of the virus to protect against worsening outbreaks.

New variant comes as America sees record-high Covid-19 hospitalizations, more than 350K deaths

Officials' detection of the new variant in the United States comes as the country continues to see persistently high rates of new coronavirus cases, hospitalizations, and deaths—which public health officials expect to spike because of Americans gathering with others over the recent holidays.

On Saturday, U.S. officials reported 291,300 new cases of the novel coronavirus, setting a new single-day record for the most cases the country has reported in a single day, the New York Times reports. However, observers note that the number may have been inflated by a reporting backlog tied to the holidays.

Because of the delay in reporting—and the lag between the time a person becomes infected with the coronavirus and when they become ill or hospitalized—experts say the United States will likely not see a spike in coronavirus cases stemming from travel and gatherings during the holidays until the second week of January.

"Things are bad enough as they are right now, but they could get worse in the next couple of weeks," Fauci said, adding, "[A]s we see the lag that happens when an event occurs like the Christmas and New Year's holiday. You usually have a couple of week lag before you see an additional uptick of cases, which is always followed by hospitalizations and deaths."

According to data compiled by the Times, U.S. officials as of Monday morning had reported a total of about 20.6 million cases of the novel coronavirus since America's epidemic began.

According to the Times, the United States' average daily number of newly reported coronavirus cases over the past week was 212,965—which is down by 1% when compared with the average from two weeks ago.

As of Monday morning, data from the Times showed that the rates of newly reported coronavirus cases were "staying high" in Washington, D.C., and 31 states that have had a daily average of at least 15 newly reported cases per 100,000 people over the past week. Those states are Alabama, Arizona, Arkansas, California, Connecticut, Delaware, Florida, Georgia, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Mississippi, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Oklahoma, Oregon, South Carolina, South Dakota, Texas, Utah, Vermont, Virginia, Washington, and West Virginia.

Meanwhile, the Times' data showed that, as of Monday morning, the daily average number of newly reported cases over the past seven days was "going down" in Puerto Rico and 18 states that had been seeing comparatively higher rates of coronavirus transmission. Those states are Alaska, Colorado, Idaho, Illinois, Indiana, Iowa, Michigan, Minnesota, Montana, Nevada, New Mexico, North Dakota, Ohio, Pennsylvania, Rhode Island, Tennessee, Wisconsin, and Wyoming.

In Guam, Hawaii, and the U.S. Virgin Islands, meanwhile, rates of newly reported coronavirus cases were "staying low" as of Monday morning, the Times' data showed.

Meanwhile, U.S. hospitalizations for Covid-19, the disease caused by the novel coronavirus, reached a new high on Sunday, according to data from The Atlantic's COVID Tracking Project. The data showed that 125,544 Americans with Covid-19 were hospitalized for treatment on Sunday, including 23,231 who were receiving care in an ICU and 7,942 who were on a ventilator.

Hospitals throughout the United States have reported being overwhelmed with Covid-19 patients, the Wall Street Journal reports. For example, data shows Covid-19 patients are crowding hospitals in some metro areas, straining providers and exceeding occupancy levels, according to the Journal.

"It's a desperate time," Eric Toner, a senior scholar with the Johns Hopkins Center for Health Security, said. "This is what we have been warning about for a year now. If we let our hospitals get overrun, we're going to see a lot more deaths, not only among [Covid-19] patients, but heart attacks and strokes."

As of Monday morning, U.S. officials had reported a total of about 351,682 U.S. deaths linked to the novel coronavirus since the country's epidemic began.

(Gutierrez et al., New York Times, 1/3; Higgins-Dunn, CNBC, 1/2; Owens, "Vitals," Axios, 1/4; Budryk, The Hill, 12/28; Jacobs, New York Times, 1/4; Bowden, The Hill, 1/3; Evans et al., Wall Street Journal, 1/3; Klein, CNN, 12/29; Jett/Shaver, New York Times, 1/3; New York Times, 1/4; "The COVID Tracking Project," The Atlantic, accessed 1/4).