Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

The winter season and cold weather forcing people to socialize and work indoors, as well as travel and family gatherings associated with the holiday season, will likely amount to a “terrible” situation in January, the veteran immunologist said as the global COVID-19 death toll exceeded 1.9 million.

“We want to get it to 1 million vaccinations per day,” he added. “The idea about having everyone for at least 100 days — at least — wear a mask. Everyone uniformly, so we don’t have disparities where some people are adhering to public-health measures, and others are not.”

As of Thursday morning, 5.9 million people in the U.S. had received their first vaccine dose and 21.4 million doses had been distributed in total, according to the CDC.

“And then also a greater interaction, cooperation between the federal government and the states, instead of letting the states in some respects do things on their own — to help them not only with plans, but with resources,” Fauci added in the interview.

However, Fauci noted that people have COVID-19 fatigue and a national lockdown is not feasible. “I don’t think this is something that we’re ready for on a countrywide basis. But, you know, you have to keep your eye on everything that’s going on and always keep all options open.”

“As the months go by, I would expect by the time we get to April, it will be what we call open season on vaccines,” he added. “Everyone will be able to get a vaccine. So I think by the end of the summer, if we get 70% to 85% of the population vaccinated and get a good herd immunity.”

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Fauci has previously warned that Americans are facing a “dark time” and the potential surge over the holidays could lead to a dark January, “This may be even more compounded because it’s a longer holiday,” he told CNN last month. Infections have exceeded 89.2 million worldwide.

The U.S. set a record for COVID-19-related hospitalizations this month with more than 131,889 patients, and the number of people with the virus in ICUs has surpassed 23,866. The U.S. had 21.9 million cases and 369,830 fatalities as of Saturday, according to Johns Hopkins University.

The U.S. lost at least 4,111 lives on Thursday from COVID-19, the most in a 24-hour period since the start of the pandemic, according to a New York Times tracker, and reported a record 280,028 new cases. Those do not, for the most part, include those who are asymptomatic.

Pfizer PFE, +2.00% and German partner BioNTech SE BNTX, +2.00% have said that a final analysis of their vaccine candidate showed 95% efficacy. Meanwhile, Moderna MRNA, +12.20% said its vaccine candidate was about 94% effective.

On Friday, BioNTech and Pfizer said an in vitro study found that their COVID-19 vaccine neutralizes the two new highly infectious variants that have emerged in the U.K. and South Africa. The results were published on the preprint service bioRxiv and have not yet been peer-reviewed.

A vaccine candidate from AstraZeneca AZN, +1.43% and the University of Oxford is safe and effective and showed an average efficacy of 70% in a pooled analysis of interim data, according to a recently published peer-reviewed study.