A line started to grow outside the Worcester YMCA well before sunrise.

The first person in line Saturday morning, vying to get a one-shot Johnson & Johnson COVID-19 vaccine as a part of a walk-up equity clinic in Worcester, lined up around 2:30 a.m., officials said. The next person came at 3 a.m.

By 9 a.m., the scheduled start time for the clinic, hundreds were waiting on the sidewalk. The line snaked down Main Street and curled through the YMCA’s parking lot. Some residents brought folding chairs, anticipating a long wait.

But that wait was worth it to residents who wanted to feel safe during the ongoing pandemic.

“Knowing that you’ve got the vaccine is a big relief because you never know where [the virus] is coming from,” resident Joe Rivera said while waiting in line outside the YMCA. He was a little worried about the vaccine shot hurting, but those worries were dwarfed by the risk of getting the virus.

Some people in line said they were scared of the coronavirus. Others wanted to get vaccinated so they can feel safe at work, or so they can safely travel.

Valerie Diaz said she’s planning a trip to see her family in Puerto Rico, so she made Saturday’s clinic a priority. She lined up outside around 6:15 a.m.

“I wanted to be safe because of how everything is right now,” Diaz said. “I wanted to be safe, my family to be safe.”

Because Diaz lined up so early, there was no traffic in the Main South neighborhood on her way to the YMCA. Later in the morning, the streets were busy as more residents went to line up for the clinic.

“I’m really satisfied with how everything is going,” Diaz said while sitting in the Y’s gym, waiting a few minutes after her shot just in case of any side effects.

The shot hurt only a little, she said. Just a pinch.

In Worcester, 7,706 vaccine doses have been administered to more than 5,391 people through the mobile vaccination sites as of April 9, according to officials. That includes 3,623 first doses, 2,315 second doses and 1,768 of the single-shot J&J vaccine.

There have been 64 mobile vaccination clinics in Worcester so far, including the event at the YMCA on Saturday.

During the city’s weekly COVID-19 briefing on Thursday, City Manager Edward Augustus said that overall, 29% of the city’s population has received at least one dose of the vaccine while 16% are fully vaccinated. Both numbers grew by 4% from last week.

Outside the YMCA on Saturday, Augustus said the crowd at the clinic was a good sign, particularly given worries about vaccine hesitancy.

“We’re all concerned about hesitancy, but at this stage of the game, we’re seeing a lot of interest in getting the vaccine as quickly as folks are eligible and it’s a great thing,” Augustus said.

Augustus said vaccine supply has started to pick up and that the city had received an influx of the Johnson & Johnson single shot, which was being administered Saturday. The city had about 2,000 doses to give out and the manager was optimistic they could vaccinate everyone who lined up.

“For these equity clinics that are not appointment-based, the J&J is a perfect tool,” he said. This was the city’s first walk-up clinic.

Given the turnout Saturday, Augustus said he expects the city may have more walk-up clinics. The YMCA is an ideal spot because of its capacity with its gym, but Augustus said the city will move through the city with other mobile clinics.

“We’re dedicated to this issue,” Mayor Joseph Petty said. “We have a good distribution of communities of color in this line here. I think if the vaccine’s there, the majority of people will be vaccinated.”

Worcester Health Commissioner Dr. Matilde Castiel said that through all the mobile clinics in the city so far, she has not seen any major adverse reactions to the vaccine.

“I’m very comfortable that this is safe and effective, just like Moderna, just like Pfizer,” Castiel said of the Johnson & Johnson shot.

Planning a mobile clinic like Saturday’s takes a city effort, Castiel said.

“This is something that the community wants and they don’t have access and this is a way to be able to have access,” she said. “Hopefully what we’re trying to do is making sure that everybody does get a vaccine as long as they’re all [eligible].”

Worcester District 4 City Councilor Sarai Rivera, who represents the Main South community where the YMCA is located, noted that Latino and Black residents have been disproportionately affected by the pandemic. And then there were language, accessibility and technology barriers in trying to get an appointment once vaccine doses were available.

“This is fighting the barriers of being able to access the vaccine,” Rivera said. “As great as the Worcester State University [vaccination site] is, for the public in general, we saw through the equity task force that we don’t even have proper bus route [there.]”

Rivera said efforts to spread the word about Saturday’s clinic included radio and TV ads, door-knocking and social media.

National Grid volunteers were on-site Saturday. The company has helped Worcester by transporting vaccination-related supplies to various sites across the city and has donated supplies, including water and alcohol wipes.