A COVID-19 vaccine manufactured by the British-Swedish firm AstraZeneca appears to provide strong protection three months after just one dose while also curbing spread of infections, researchers said Wednesday.

British Health Secretary Matt Hancock said the study supports a strategy of delaying the second shot so more first doses can be delivered to more people. Researchers also found a 67% reduction in positive “swabs” among those vaccinated – crucial news because if no virus is present, the virus can’t spread.

AstraZeneca has not yet applied for emergency use authorization for its vaccine in the U.S. Just two vaccines, by Pfizer-BioNTech and by Moderna, have been authorized in the U.S., and both require a second dose.

Dr. Anthony Fauci lauded the British researchers for responding to their data but said the U.S. will continue to recommend that Pfizer booster shots be given about 21 days after the initial shot, Moderna boosters about 28 days after.

“We also are going very much by the data and science that has emanated out of very large clinical trials,” Fauci said. “We feel strongly that we will go by the science, which dictated for us the optimal way for us to get the 94-to-95 percent response.”

COVID-19 has killed more than 448,000 Americans, and infections have continued to mount despite the introduction of a pair of vaccines late in 2020. USA TODAY is tracking the news. Keep refreshing this page for the latest updates. Sign up for our Coronavirus Watch newsletter for updates to your inbox, join our Facebook group or scroll through our in-depth answers to reader questions.

In the headlines:

►Pope Francis received his second vaccine dose on Wednesday. The pope, 84, had the first jab on Jan. 13.

►Dr. David Chokshi, New York City’s Health Commissioner, said he has tested positive and is experiencing mild, “manageable” symptoms. “This is a reminder – if we ever needed one – that COVID is still with us and we all must continue to wear masks, wash our hands, socially distance and stay home if feeling ill.”

►Japan enacted legislation allowing officials to fine violators of coronavirus orders. The country is struggling to slow the latest surge of infections amid growing uncertainty about the distribution of COVID-19 vaccine, considered key to holding the Olympics this summer.

►The National Park Service will now require all visitors and employees to wear masks inside buildings and facilities and on lands “when physical distancing cannot be maintained.” That includes busy and narrow trails.

►A new study finds that cleaner air from the pandemic lockdown warmed the planet a bit in 2020, especially in places such as the eastern United States, Russia and China.

►How many people in your state and across the U.S. have received the COVID-19 vaccine so far? Check the USA TODAY vaccine tracker.

???? Today’s numbers: The U.S. has 26.4 million confirmed coronavirus cases and more than 448,000 deaths, according to Johns Hopkins University data. The global totals: More than 104 million cases and 2.2 million deaths. Nearly 56 million vaccine doses have been distributed in the U.S. and about 34 million have been administered, according to the CDC.

???? What we’re reading: Raymond James Stadium not only is site of Super Bowl 55, but also a symbol of the pandemic.

CDC chief: New cases, hospitalizations in a ‘consistent downward trajectory’

New infections and hospital admissions continue to decrease and the U.S. now appears to be in a consistent downward trajectory “for both to these important outcomes,” Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Wednesday. But she warned that the proliferation of variants could reverse those trends. Walensky also acknowledged that daily deaths continue to edge higher.

“While deaths have continued to increase, the pace appears to be slowing,” she said. “The recent decline in hospitalizations gives us hope that the number of deaths should start to decrease in coming weeks.”

For the first time since Nov. 13, the United States has reported fewer than 1 million new coronavirus cases over a seven-day period. The weekly total peaked at more than 1.7 million a few weeks ago. Johns Hopkins University data shows 989,974 new cases in the seven-day period ending Tuesday. Still, at that pace 98 Americans were reported positive very minute.

Dr. Fauci won’t be attending your Super Bowl party

Dr. Anthony Fauci is warning America to “just lay low” rather than gathering for Super Bowl parties on Sunday. President Joe Biden’s chief medical adviser said during TV interviews Wednesday that now isn’t the time to host watch parties because of the possibility that guests could be infected with the coronavirus and could sicken others. The NFL has capped attendance for the game in Tampa at 22,000, citing the pandemic and citywide coronavirus mandates. Fauci says the best thing people can do is watch the game on TV at home with the people in your household.

“You don’t want parties with people that you haven’t had much contact with,” he told NBC’s “Today” show. “You just don’t know if they’re infected, so as difficult as that is, at least this time around, just lay low and cool it.”

People who smoke are prioritized to get the COVID-19 vaccine

As more Americans anxiously wait their turn to get the COVID-19 vaccine, people are discovering that smokers are one of the priority groups for vaccination. The revelation has drawn frustrations on social media, but a study published last week in the peer-reviewed journal JAMA Internal Medicine found that people who smoke or who have smoked in the past are more likely to be hospitalized or die from COVID-19.

“I could see why people would feel as if that would be unfair,” said Dr. Samuel Kim, a thoracic surgeon at Northwestern Medicine in Chicago. “But people who are smokers are in general at higher risk for getting sicker when they develop COVID-19.” Read more here.

– Adrianna Rodriguez

LAPD threatens arrests if protesters again disrupt mass vaccination site

After protesters disrupted drive-in COVID-19 vaccinations at Dodger Stadium in Los Angeles last week, local police said Tuesday that any further protests would prompt “immediate and swift” arrests.

“It’s my expectation and direction that … individuals will be arrested, they’ll be cited, and their actions will be caused to be ceased,” said Police Chief Michel Moore during a virtual meeting of the Police Commission, according to the Los Angeles Times. “This going forward is a means of ensuring that the lines will stay open, that the vaccine sites will be unhindered.”

The stadium, one of the largest vaccination sites in the country, was temporarily shut down Saturday because dozen of protesters blocked the entrance. However, no vaccination appointments were canceled and the site was not shut down permanently, according to Moore.

NYC mayoral candidate Andrew Yang tests positive for COVID-19

Andrew Yang, the entrepreneur turned presidential candidate who is now running for New York City mayor, has tested positive for COVID-19, he announced Tuesday. Yang said he had tested negative as recently as this weekend but then received a rapid test that had a positive result, he tweeted on Tuesday. “I’m experiencing mild symptoms, but am otherwise feeling well & in good spirits,” Yang tweeted.

Yang said he was quarantining. Among New York City mayoral candidates, he has been among the most prolific in-person campaigners in a race that has been otherwise forced online because of the pandemic.

– Ryan W Miller

Contributing: The Associated Press