Coronavirus Watch: Up to 4% of US cases are of B.1.1.7 variant strain, officials say

Somewhere between 1-4% of reported COVID-19 cases in the U.S. are due to the B.1.1.7 variant first identified in the United Kingdom, health officials said Wednesday.

"The B.1.1.7 (variant) is becoming widespread in the U.S.," Dr. Anthony Fauci said, reiterating that the strain may become dominant in the U.S. by the end of March. Vaccines do well against the variant in test tube studies, Fauci said.

A variant from South Africa has been identified in a few U.S. states, but "it is very likely more prevalent than that," Fauci said. Vaccine-induced immunity "stays within the realm of protection" from the virus, Fauci said.

"Bottom line is that we have vaccines that work well against it, and obviously we're going to be planning, if necessary, to upgrade vaccines in the future if we ever have to do that."

It's Wednesday, and this is the Coronavirus Watch from the USA TODAY Network. Here's more news that you need to know:

• The number of known variant cases in the U.S. has surged 73% in the last week alone, according to the CDC. Nowhere has the increase been more noticeable than in Florida, which now has 343 cases of a fast-spreading variant – up from 201 cases reported during Sunday's Super Bowl, which was hosted in Tampa. Florida now has more than twice as many known variant cases as any other state; California is a distant second.
• Dr. Rochelle Walensky, director of the CDC, called on Americans to wear masks to prevent the spread of COVID-19, especially amid concerns of new variant strains. "Everyone needs to be wearing a mask when they are in public or when they are in their own home with people who do not live in their household," Walensky said. "Now is not the time to roll back mask requirements."
• The Chicago Teachers Union approved a deal Wednesday with the nation’s third-largest school district to return to classrooms amid the pandemic. More than two-thirds of the 20,000 educators who cast ballots voted to go back to work.
• Americans are perceiving less risk from the pandemic than any time since last October. Two-thirds say returning to a pre-COVID life is a moderate or large risk, according to a new Axios-Ipsos poll. One-third were more skeptical, with young people and Republicans the most likely to be little-concerned by the pandemic. The survey also found one in three Americans know someone who has died from COVID-19.
• The U.S. Food and Drug Administration on Tuesday issued emergency use authorization for a COVID-19 therapy from Eli Lilly that combines two monoclonal antibody drugs, giving doctors another option to help high-risk patients.
• Worldwide, Britons may not be allowed to vacation abroad until “everybody” in the country has been vaccinated, Transport Secretary Grant Shapps said Wednesday. Greece’s prime minister says a new lockdown in the greater Athens region will close all schools and most shops beginning Thursday. And South Africa’s health minister says the country will begin administering the one-dose Johnson & Johnson vaccine to its front-line health workers next week, scrapping its plans to use the Oxford-AstraZeneca vaccine because it "does not prevent mild to moderate disease" of the variant dominant in South Africa, Health Minister Zweli Mkhize said.

Today's numbers: The U.S. has reported more than 27.1 million COVID-19 cases and 468,000 deaths, according to data from Johns Hopkins University. Worldwide, there have been more than 107.0 million cases and more than 2.3 million deaths. About 9.9% of people in the US have received at least one vaccine shot, and about 3% of people have received both doses, according to the CDC.

See the numbers in your area here, check out where cases are rising here, and see how many vaccines your state has received here.

– Grace Hauck, USA TODAY breaking news reporter, @grace_hauck