This is our daily update of breaking COVID-19 news for Tuesday, January 5th, 2021. Previous daily updates can be found here, and up-to-date statistics are here.

New York City is in Phase 4 of reopening now, which includes zoos, botanical gardens, museums, and gyms. Citing rising hospitalization rates, Governor Andrew Cuomo suspended indoor dining in NYC starting Monday, December 14th. After being shut down for several weeks, NYC public schools partially reopened on December 7th for 3K-5th grade students, with students with special needs returning on December 10th. Certain parts of Staten Island remain under a zoned shutdown.

Get answers to questions you may have with our "Ask An Epidemiologist" series, or learn more about NYC COVID-19 testing options with our explainer. Here are some local and state hotlines for more information: NYC: 311; NY State Hotline: 888-364-3065; NJ State Hotline: 800-222-1222.

Here's the latest:

5 p.m. Facing mounting criticism over the slow vaccine rollout, Mayor Bill de Blasio on Tuesday announced that New York City will open five "mass vaccination" sites.

The sites, which will be at locations not yet been identified by the city, will operate 24 hours a day, seven days a week, according to the mayor.

Two of the sites are expected to be up and running this weekend.

As of Tuesday, more than 118,000 vaccines have been administered across the five boroughs, according to the city's vaccine tracker. That amounts to only a quarter of the total doses the city has received from the state and federal government.

The mayor's plan comes one day after Governor Andrew Cuomo pointed out that the city's public hospital system was among those which have used less than a third of its vaccine allocation. Hospital workers and nursing home residents and staff members were first in line to receive the vaccine, along with others in congregate settings.

This week, the pool of those eligible to receive the vaccine was expanded to include other frontline workers as well as other healthcare professionals.

The mayor has defended the city's rollout and has instead blamed the sluggish pace on the state and lack of clear federal guidance as well as a sufficient supply of vaccines.

On Tuesday, he called on Cuomo to allow the city to start vaccinating other essential workers and those over 75.

But the governor, at his own press briefing, pushed back on widening eligibility now, saying the number of people currently prioritized to receive vaccines outstrips the supply. The state has so far distributed 900,000 vaccines for 2.1 million health care workers.

"Obviously we don’t have enough," he said.

Part of the problem may stem from vaccine hesitancy, which city officials had not acknowledged until Tuesday.

Dr. Mitchell Katz, the head of the city's public hospital network, said that around 30% of public hospital workers had declined the vaccine.

In addition to the mass vaccination sites, the city also opened two pop-up sites in East Harlem and Lower Manhattan as part of a plan to open 250 vaccination clinics by the end of January.

The mayor said the city should have 160 of those open by the end of the week.

Cuomo has said the state would start fining hospitals that fail to use their vaccine doses, and redirect those supplies to other hospitals.

The mayor lashed out at the threat, saying, "Why don't we stop talking about fines and start talking about the freedom to vaccinate, letting the professionals do their jobs."

He added: "We are going to move with every conceivable speed, capacity, creativity, flexibility to do what we can do, but we need help from the state government."

Research Underway On Vaccines' Effectiveness Against South African Variant

11:38 a.m.: The COVID-19 variant that originated in South Africa has raised alarms for the UK health secretary as a "very, very significant problem," citing concerns that current vaccines may be less effective against it.

"I'm incredibly worried about the South African variant," the UK health secretary Matt Hancock said on BBC Radio, according to The Guardian.

Scientists caution that the vaccines' effectiveness on the South African variant is still being researched, and vaccines can be modified in a few months. But Hancock said, "This is a very, very significant problem." Health officials there have restricted all flights from South Africa.

Sir John Bell, regius professor of medicine at Oxford University, which developed a UK-permitted vaccine with AstraZeneca, said he is more concerned more about the variant from South Africa than the one spread in the UK. Both of the new strains have mutations.

"I think the vaccine will still be effective against the Kent [or UK] strain, and I don't know about the South African strain. There's a big question mark about that," Bell said.

Bell said on the UK's Times Radio that Oxford scientists are looking into whether the vaccines are effective against the strains. Scientists in South Africa are also testing to determine how effective vaccines are against the variant, the Associated Press reported.

"It's unlikely that these mutations will turn off the effective vaccines entirely," Bell added. And he said vaccines could be modified relatively quickly, echoing other scientists.

Dr. Julian W. Tang, a clinical virologist at the University of Leicester, said the strain from South Africa has more mutations than the UK variant, which "may interfere more with vaccine effectiveness."

"This does not mean that the existing COVID-19 vaccines will not work at all, just that the antibodies induced by the current vaccines may not bind and neutralise the South African variant as well as it would be the other circulating viruses—including the UK variant," Tang continued in his statement. She added vaccines "can be modified to be more close-fitting and effective against this variant in a few months."

A professor in computational systems biology at the University College London, Francois Balloux, added: "It's possible that new variants will affect the efficacy of the COVID vaccines, but we shouldn’t make that assumption yet about the South African one."

In New York State, the first case of the variant from the UK was announced Monday, with three more cases undergoing additional tests.