LOS ANGELES — “That’s the magic juice,” said registered nurse Chantil Arrington as she held up a tiny vial of the Pfizer-BioNTech COVID-19 vaccine.

The vial is where the process starts, with staff members prepping the doses to prepare for walk-up patients. The visit ends under Arrington’s recovery tent, where she gives out water bottles and Tootsie Pops.

No one likes getting a shot, or two, or now a third, but Arringtton finds that candy helps ease the anxiety.

"If they know they’re going to get a lollipop afterwards, then they’re normally more accepting of getting a vaccine," she said.

And better yet if they know they are protected, especially now with the holidays around the corner.

“They want to travel, so then I think they are taking more precautions and getting boosters and things like that," she added.

Arrington works with one of the four mobile vaccine units run by St. John’s Well Child and Family Health Express. The buses go to different pop-up locations around the city and do outreach for the unhoused population. There are days when they’ve administered close to 400 shots in one day, and with the holidays, another variant and the booster now approved for 16- and 17-year-olds, Arrington says things are beginning to pick up steam.

“We’re going to see even more patients, I expect,” she said.

Patients include Silvia Chale and her mom. Chale isn’t due for her booster yet but brought her mom for the extra dose.

“We are preventing that she gets sick again,” she said.

As Chale explained, her mom was hit hard by COVID last year and had been unable to breathe. She spent a week in the hospital, and Chale and her brother were terrified of losing her, which is why they take the virus and preventative steps seriously. They’re even planning for yet another quiet holiday celebration with just the immediate family to limit possible exposure.

“It's hard,” Chale said.  “If she gets sick again, I don’t want that.”

According to the Los Angeles County Department of Public Health, many of the confirmed COVID cases have involved individuals who were fully vaccinated and showed either no symptoms or mild illness. And that isn’t a failure of the vaccine, it’s a success, says Mario Chavez, St. John’s director of government affairs and community outreach.

"That’s really what the COVID vaccine is meant to do, to prevent serious disease and, you know, hospitalization," he said.

While the pop-ups specifically target areas and communities with low vaccination rates — including Compton, East LA and Boyle Heights — Chavez and county health officials are concerned about another surge fueled by holiday festivities.

“I know most people feel like, oh well, COVID is a thing of the past, but COVID is still here,” he said. “It’s very important that you get your booster now so by the time we get to the family gatherings, we are as protected as can be.”

A filing tray at the registration table lists the different reasons someone might be coming to the clinic: first, shot, second, booster, pediatric. But no matter how many shots they’ve gotten, Arrington tells people not to let their guard down.

"Still hand-washing, social distancing, wearing a mask because you can still catch it," she said. "You probably won’t end up in the hospital or die from it, but you can still get it and you can still spread it."

To find a vaccination site, visit wellchild.org or myturn.ca.gov.