Updated at 4:30 p.m. Dec. 30

The city of Boston is adding two walk-in COVID vaccination clinics to the array of First Night festivities slated for New Year's Eve, Mayor Michelle Wu announced at a press conference Thursday.

From noon to 7 p.m., when the city's fireworks event begins, vaccine doses will be offered outdoors in Copley Square by representatives of the Whittier Street Health Center. After the fireworks conclude, shots will be offered until 11 p.m. inside the Central Library branch of the Boston Public Library, 700 Boylston St., administered by the Boston Public Health Commission.

Both clinics will offer first doses, second doses or boosters of the Pfizer vaccine. The daytime clinic will be open to individuals 5 and older, and the second clinic will be open to individuals 12 and older.

"This is really important.," Wu said. "So we want to make sure people who are coming, visiting Boston, coming into the city to enjoy the time with your family and friends remember that there will be a vaccination and booster clinic right on site. And we hope you take advantage of it."

In addition, the Whittier Street Health Center will be distributing 1,000 rapid antigen tests in Copley Square on Dec. 31.

Wu also noted that indoor events sponsored by the city have been moved outside to limit the spread of the coronavirus as the omicron variant spikes in Massachusetts and elsewhere.

"As we come together to celebrate community, our joy, and a fresh start in 2022, we must also recognize the moment that we still very much are in," Wu said. "We are in a winter surge, driven by the omicron variant, and we need to take action to protect ourselves, our families, and our communities at large. "

As of midday Thursday, the First Night schedule still included indoor events controlled by two local churches.

Dr. Bisola Ojikutu, the head of the Boston Public Health Commission, urged people who are feeling sick, who've recently been in close contact with someone who tested positive for the coronavirus, or who are awaiting the results of a test to not attend First Night or any other New Year's gatherings.

Ojikutu also said that, in the coming weeks, Boston will release details about several new testing sites.

"Please be aware that we are deeply concerned about the limited availability of testing in many parts of our city," Ojikutu said.

Ojikutu also touted increased access to vaccines with new walk-in sites at City Hall, Madison Park High School, Melnea Cass Recreational Complex, and locations affiliated with the Boston Public Schools.

Wu also urged people attending the event to take public transit, rather than drive. MBTA services will be free after 8 p.m., with trains, buses and commuter rail running on an augmented schedule.

"I've been on the T every single week since taking office, and have had a great experience with fellow passengers there — although no one talks to me, but it's OK," Wu said.

"If a train car is looking like it's already full, or getting crowded, you can wait for the next one," she added. "Because they will be coming more frequently."

This story was updated to clarify details about the new walk-in sites in Boston, separate from the First Night events.