NEW YORK (CBSNewYork) —  While many are still weighing whether to get their first COVID-19 vaccination, millions have already lined up for a third dose.

Since the Centers for Disease Control and Prevention recommended booster shots in September, more than 25 million people have received theirs — with more than two million of those given out in the Tri-State Area.

READ MORE: With COVID Numbers Climbing Again Across Tri-State Area, Officials Again Push For People To Get Vaccinated

CBS2’s Dana Tyler visited one New Jersey county experiencing a booster boom.

Dr. Shereef Elnahal, president and CEO of University Hospital in Newark, knows boosters are vital. The hospital is calling patients and using social media platforms, like Facebook Live, to answer questions about how people can best protect themselves and their families from COVID.

“A booster is just basically a way to train your immune system to fight the coronavirus even better,” Dr. Elnahal told Tyler.

“So for Pfizer, it’s basically the same shot. For Moderna, it’s half the dose. And for Johnson & Johnson, it’s the same dose for adults,” he continued.

“The idea is that your immunity does not last forever when you get vaccinated. It certainly doesn’t last forever if you get the actual infection.”

James Eubanks, 67, works as a shuttle bus driver at Newark Liberty International Airport. He is in constant contact with strangers and didn’t hesitate to roll up his sleeve to get a Pfizer booster shot.

COVID VACCINE

But is one booster enough to keep breakthrough infections at bay?

“We don’t know what the ongoing frequency will be, though. So it may be the case that it’s every year, it may be the case that it’s every two years,” said Dr. Elnahal. “We won’t know until enough time elapses for the clinical trials to mature and for the epidemiological investigations to mature.”

READ MORE: As COVID Cases Climb In Tri-State Area, Pfizer Says Its Vaccine Booster Appears To Protect Against Omicron Variant

In Essex County, New Jersey, more than 2,800 people have died from COVID — the highest in the state. The county runs five vaccination sites.

“We’ve been pushing very, very hard here. We have a call center. I’ve been sending mailings out,” Essex County Executive Joseph DiVincenzo said. “We’re putting in 150% into this… It’s about life and death, especially in this county, the number of people that we’ve lost.”

At least 30,000 booster shots have already been administered in the county.

CORONAVIRUS PANDEMIC

For people with underlying health conditions, a booster shot is critical.

“So I have chromic lyme, and I see an infectious disease doctor, and he advised me that I would be a really good candidate for a booster,” said West Caldwell resident Maryann Venancio.

“I actually looked forward to it,” Mike Fleming, of South Orange, said. “I was waiting for Moderna to be approved, and here we are.”

“I want to get rid of this virus or reduce it to less than a pandemic status, and I want to do my part to make that happen,” West Orange resident John Vogt added.

With children ages 5 to 11 now eligible for COVID vaccines, will they also need additional doses?

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“I don’t know if children will need boosters. I think it’s way too early to tell,” said Dr. Elnahal.