The British government on Friday released a study showing a variant of the novel coronavirus first detected in the United Kingdom called B.1.1.7, which is also circulating in the United States, is "likely" more deadly than the original version of the novel coronavirus—and experts fear B.1.1.7 and similar new coronavirus variants could threaten recent progress in America's coronavirus epidemic.

When will the Covid-19 epidemic end? Here are the good, bad, and ugly scenarios.

British government finds coronavirus variant 'likely' associated with higher risk of death

Earlier research has shown that the B.1.1.7 variant, which officials first identified in the United Kingdom in December 2020, is about 56% more transmissible than earlier variants of the novel coronavirus. Since last December, scientists have identified the variant in at least 45 countries, including the United States.

For the new study released Friday, scientists from the British government analyzed information from multiple databases across the United Kingdom and assessed data on a larger sample of Covid-19 patients than they had for previous research on the B.1.1.7 variant.

The scientists in the study wrote that the data showed B.1.1.7 "is associated with an increased risk of hospitalization and death compared to" earlier variants of the novel coronavirus. Overall, the British scientists estimated that B.1.1.7 is 30% to 70% more deadly than earlier variants of the virus.

"The overall picture is one of something like a 40% to 60% increase in hospitalization risk, and risk of death," Neil Ferguson, an epidemiologist and scientific adviser to the British government, said.

However, there's some reason for caution when interpreting the findings, experts and observers said.

For instance, the scientists noted that they were 55% to 75% confident in their assessment of the variant's deadliness based on the data they had available to them, the New York Times reports.

In addition, observers have pointed out limitations in the data available to examine B.1.1.7. For example, the Washington Post reports that there are gaps in the data "among critical demographics, such as nursing homes."

Along those same lines, the Times reports that it's ultimately unclear whether B.1.1.7 may result in a higher risk of death, because the variant spreads more easily, including through nursing homes and other settings where people are more vulnerable to the virus.

Muge Cevik, an infectious disease expert at the University of St. Andrews in Scotland and a scientific adviser to the British government, also noted those limitations, saying there could be "other explanations of this increased severity," including that B.1.1.7 may "transmit disproportionately in settings with frailer people," such as nursing homes.

However, Cevik added, "I think [the study's] results are possibly genuine, although there are still several limitations and we need to understand what causes it."

Experts worry new coronavirus variants may create 'stumbling block' in America's epidemic

Experts worry the spread of new coronavirus variants such as B.1.1.7 in the United States could reverse recent progress the United States has seen in its epidemic—and a new, preprint study published Sunday in medRxiv may add to those concerns.

In the study, which hasn't yet been peer reviewed, researchers identified seven new variants of the novel coronavirus that appear to have originated and are circulating in the United States that may be similar to B.1.1.7.

The researchers found that, like B.1.1.7, the seven new variants have mutations in a gene that affects how the novel coronavirus enters human cells, which could make them more contagious. However, the researchers said they did not yet have evidence confirming that the seven new variants are more transmissible than earlier variants of the novel coronavirus.

"There's clearly something going on with this mutation," said Jeremy Kamil, the study's co-author who studies virology at Louisiana State University. "I think there's a clear signature of an evolutionary benefit," Kamil added.

Last month, CDC Director Rochelle Walensky separately noted that some new "variants that have been identified recently seem to spread more easily, they're more transmissible, which can lead to an increased number of cases and increase stress on our already taxed health care system."

According to CDC data, the United States as of Sunday reported 1,193 total cases of novel coronavirus variants across 40 U.S. states. That total includes:

• 1,173 cases of the B.1.1.7 variant first identified in the United Kingdom, which research suggests is also possibly less susceptible to Covid-19 vaccines than earlier variants of the virus;
• 17 cases of the B.1.351 variant first identified in South Africa, which research suggests is more transmissible and less susceptible to Covid-19 vaccines than earlier variants of the virus; and
• Three cases of the P.1 variant first identified in Brazil, which research suggests is more transmissible and less susceptible to vaccines than earlier variants of the virus.

During an interview with "Axios on HBO" that aired Sunday, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases and chief medical adviser to the Biden administration's Covid-19 response, said the newly emerging variants could create a "stumbling block" in America's recent progress in containing the country's coronavirus epidemic, despite the effectiveness of Covid-19 vaccines.

While "things are going in the right direction ... we're also going to be challenged by the appearance of variants or mutants that have appeared, some of which have a functional influence on how we're gonna respond to them," Fauci said. "Fortunately, others are well covered by the vaccine, but not all of them."

And although Covid-19 vaccines may help to protect Americans against the new variants, at least to some degree, the United States has been struggling to quickly roll out its Covid-19 vaccines, with supply running far short of demand in many states, the Times reports.

CDC data shows that, as of Monday morning, the federal government had distributed about 70 million doses of the United States' two authorized Covid-19 vaccines, which each require that patients receive two doses a few weeks apart. According to CDC's data, as of Monday morning, about 52.9 million doses of the vaccines had been administered in the United States, That total included 38.3 million people who'd received "one or more doses" of a vaccine and about 14 million who'd received two doses, the data shows.

Where America's coronavirus epidemic stands

Recent data indicates America's coronavirus epidemic has improved since last month's peak in reported cases, hospitalizations, and deaths. However, the reported rates of each of those metrics remain high.

According to data compiled by the Times, U.S. officials on Monday reported about 55,552 new coronavirus cases, though that total may be skewed because of a reporting lag over the President's Day holiday. As of Tuesday morning, officials had reported a total of about 27.7 million cases of the novel coronavirus since the United States' epidemic began.

According to the Times, the United States' average daily number of newly reported coronavirus cases over the past week was 85,812—down by 41% when compared with the average from two weeks ago, when the United States was in the midst of its worst peak in newly reported cases.

As of Tuesday morning, data from the Times showed that the rates of newly reported coronavirus cases were "staying high" in Nebraska, South Dakota, and Vermont, which have each reported a daily average of at least 15 newly reported cases per 100,000 people over the past week. In contrast, rates of newly reported coronavirus cases were "staying low" as of Tuesday morning in Guam, Puerto Rico, the U.S. Virgin Islands, and 11 states. Those states are Alaska, Hawaii, Idaho, Maine, Michigan, Minnesota, Missouri, North Dakota, Oregon, Washington, and Wyoming.

All other states and Washington, D.C., had been seeing comparatively higher rates of coronavirus transmission, but the daily average of newly reported coronavirus cases over the past seven days in those areas was "going down" as of Tuesday morning, according to the Times' data.

U.S. hospitalizations for Covid-19, the disease caused by the novel coronavirus, remained high as of Monday, but still were down significantly from record highs reported last month. According to data from The Atlantic's COVID Tracking Project, there were 65,455 Americans with Covid-19 hospitalized for treatment on Monday, including 13,799 who were receiving care in an ICU and 4,454 who were on a ventilator. Monday marked the eleventh consecutive day that fewer than 90,000 Americans with Covid-19 were hospitalized for treatment, and it had the lowest number of Covid-19 hospitalizations in America in nearly three months.

Similarly, the United States' rate of newly reported deaths linked to the novel coronavirus has declined over the past two weeks, though it also remains high. According to data from the Times, U.S. officials reported about 994 new deaths linked to the virus on Monday, though that total also may be skewed because of a reporting lag over the President's Day holiday. As of Tuesday morning, officials had reported a total of about 486,148 U.S. deaths linked to the virus since the country's epidemic began.

(Mueller/Zimmer, New York Times, 2/13; Berger, Washington Post, 2/13; Zimmer, New York Times, 2/15; Bowden, The Hill, 2/15; Porterfield, Forbes, 2/14; Talev, Axios, 2/15; Tompkins et al., New York Times, 2/15; Castronuovo, The Hill, 2/12; New York Times, 2/16; "COVID Tracking Project," The Atlantic, accessed 2/16).