Appointments for COVID-19 booster vaccines are filling up across the Hudson Valley due to concerns about the omicron variant.

Estella Crespin got a Pfizer booster vaccine at the National Guard Armory in Yonkers on Monday. She says the omicron variant is at the forefront of her mind.

"It’s necessary to be protected. There are too many people not vaccinated,” she says. “I don't know how much the booster vaccine will protect me, but either way I'm getting the vaccine."

Booster vaccine appointments are becoming hard to come by, with many vaccine locations now booked a week or more out. Scientists are racing to determine if existing vaccines adequately protect against the new variant.

Experts say the vaccine is the best defense against omicron, which is emerging as the most contagious variant yet.

"This is going to spread like wildfire everywhere throughout the world,” says Dr. Harish Moorjani, an infectious disease consultant at Phelp's Hospital.

All New Yorkers 18 and older are now eligible for COVID-19 vaccine boosters, but there are some restrictions.

Those who’ve had Pfizer of Moderna vaccines have to wait at least six months since their last dose. Those who had the Johnson & Johnson, the waiting period is two months.

“All of us are going to meet COVID somewhere, sometime. The question is – are we going to meet it prepared with vaccinations or…are we going to meet it unprepared,” Moorjani says.

For more information on where you can get your COVID-19 vaccine, click here.