Dr. Anthony Fauci, Health and Human Services Secretary Alex Azar and National Institutes of Health Director Francis Collins were vaccinated Tuesday with the newly authorized Moderna vaccine, which the NIH helped develop.

Azar said to the NIH staff, “This is one of your finest accomplishments.”

Hours before getting vaccinated, Dr. Anthony Fauci told ABC News' "Good Morning America" Tuesday, “I want to symbolize to people the importance that everyone gets vaccinated who can get vaccinated.”

Fauci will receive the Moderna vaccine, which the National Institutes of Health helped develop. Fauci is director of the National Institute of Allergy and Infectious Diseases, which is part of the NIH.

Fauci said the general population will likely start receiving vaccines at the end of March or beginning of April -- but it’s unclear how long that process will take.

“It may take two, three, four months or more before you get everyone vaccinated that wants to be vaccinated,” Fauci said.

In the wake of an uptick in cases in England linked to a new COVID-19 variant, Fauci said he “would not be surprised” if the variant is in the U.S.

“When you have this amount of spread within a place like the U.K., you really need to assume that it’s here already. And certainly is not the dominant strain, but I would not be surprised at all if it’s already here," he said.

The reproduction rate of the new variant is 0.4 higher than other known strains, Dr. Maria Van Kerkhove, the World Health Organization’s COVID-19 technical lead, said Monday. That means the number of people an infected individual transmits to increases from 1.1 to 1.5 with the new variant.

There’s "zero evidence" that the new variant causes more severe disease, said Dr. Mike Ryan, executive director of the WHO’s Health Emergencies Programme.

BioNTech CEO Ugur Sahin is confident that the pharmaceutical company's coronavirus vaccine will work against the new U.K. variant of the virus.

"We don't know at the moment if our vaccine is also able to provide protection against this new variant," Sahin told a news conference Tuesday, after the vaccine was approved for use in the European Union. "But scientifically, it is highly likely that the immune response by this vaccine also can deal with the new virus variants."

He explained that the proteins on the U.K. variant are 99% the same as the ones on the original strain, so BioNTech has "scientific confidence" that its vaccine will be effective on the variant as well.

Still, more studies need to be done.

"But we will know it only if the experiment is done and we will need about two weeks from now to get the data," Sahin said. "The likelihood that our vaccine works ... is relatively high."

Los Angeles officials arrested over 60 people involved in underground parties over the weekend.

In a statement, the Los Angeles County Sheriff’s Department said the parties were considered superspreader events, as they violated COVID-19 health protocols.

Around 10:45 p.m. Saturday, the Los Angeles Police Department responded to an underground party event in Los Angeles and found two people shot. One of the victims was pronounced dead at the scene, according to a statement from the LASD.

Then, at around 12:30 a.m. Sunday, officers responded to another underground party in Compton, where they arrested 67 people: 61 adults and six juveniles. One firearm was recovered.

A third underground party, located in Los Angeles, was shut down by the LAPD after a shooting took place.

"Sheriff Alex Villanueva has made it clear he will seek out and take law enforcement action against all underground party events occurring anywhere within Los Angeles County, who fall under the Health Orders of the County’s Department of Public Health," the LASD said in their statement. "The goal of these enforcement actions is to reduce the spread of COVID-19 and the risk to our vulnerable populations."

The New York City health care provider under investigation for allegedly misappropriating the Moderna coronavirus vaccine, told ABC News it will return its vials to the state Health Department.

The New York State Department of Health is currently probing ParCare, which has offices in Brooklyn, to determine if it misused what was an approved allocation toward members of the public not yet prioritized under current New York guidelines.

Under the current state rules, only medical workers, first responders and nursing home staff members are allowed to receive any coronavirus vaccine. Other groups will follow in future rounds.

ParCare touted the vaccine on its social media pages with a flyer that claimed the vaccines would be available on a "first come, first serve basis."

"We have set up a special system where you can reserve your slot. This will enable you to receive the vaccine as soon as it arrives to the center," the flyer said.

The flyer also claimed that the vaccines were only for people who were "elderly," "high risk" or "underlying conditions."

New York state police and other investigators were at the ParCare location in Borough Park on Saturday night.

A spokesman for ParCare told ABC News Sunday evening that it is cooperating with the state investigation and will return its unused vials.

ParCare received 2,300 doses of the Moderna vaccine, and 869 of those doses have already been administered, according to the spokesperson.

"ParCare followed all NYS DOH procedures for obtaining the Moderna vaccine and was approved by NYS DOH for distribution and by CDC as a network site. As a result, we have properly received the vaccines and have provided the documentation regarding the proper receipt of the vaccines to the NYS DOH," the spokesperson told ABC News.

With regards to the patients who received their first shot, ParCare said it will be "working with the state to ensure that we provide the second dose for our patients."

-ABC News' Sasha Pezenik and Aaron Katersky contributed to this report