What’s big and blue and could save hundreds of lives?

What’s big and blue and could save hundreds of lives? The big blue vans that the New Jersey Health Department is rolling out to deliver Covid-19 vaccines to the residents who have been the hardest to reach.

With infection rates rising again across the state — especially in crowded areas like Hudson County, where many people have been unable to schedule shot appointments online and don’t have cars to get to the vaccination centers — Gov. Phil Murphy has used federal funds to buy three customized vehicles to bring the vaccines to the people.

“They just arrived — three vans that will be outfitted with a full staff to go deep into communities and vaccinate individuals in about three weeks,” New Jersey Health Commissioner Judith Persichilli said Friday. “So we’re working with major health care systems in New Jersey to license those vans as acute care centers. … So look for big blue vans going into communities. We’re going to put one out quickly for testing so people get used to seeing the vans.”

They’re hard to miss. In addition to their color and size, they have the words “Rapid Mobile Response Team” in big letters on the side.

Inside, the vans have partitions where shots can be administered and are customized with special refrigerators so the vaccines can be transported safely, said Donna Leusner, the state Health Department’s chief spokeswoman.

“Three mobile units will be placed in the northern, central and southern parts of the state and will go into underserved communities including congregate settings, such as high-rise senior centers,” Leusner said in an email to NBC News.

Vaccination vans similar to these are also being used in Connecticut, California, New Mexico, South Carolina and Virginia to get shots into the arms of hard-to-reach populations. And in Tennessee, the First Tennessee Development District Foundation is using more than $500,000 in grant money to buy and customize three vaccination vans similar to the ones in New Jersey.

While the Tennessee vaccination vans will likely serve a mostly rural population, a large proportion of the people New Jersey health officials are targeting live in the crowded cities that sit across the Hudson River from New York City.

And they’re in a race against time.

Public health experts have warned that New Jersey could see a third wave of infections even as it has been ramping up its vaccination programs.

“If there’s a sustained 7- and 14-day trends of case increases and a commensurate increase in positivity rate, you’re pretty much in another wave,” Shereef Elnahal, CEO of University Hospital in Newark, New Jersey, told WNYC radio.

New Jersey currently leads the nation in case rate, with nearly 46 per 100,000 residents, according to the Covid Act Now vaccine and risk tracker.

Nearly 16 percent of New Jersey residents have been fully vaccinated, according to Becker’s Hospital Review.

But the proportion of Black and Hispanic residents who have gotten their shots is much lower in New Jersey and in other states, according to research compiled by the Kaiser Family Foundation.

The problem is especially acute in Hudson County, “which is the most diverse county in the state,” Hudson County spokesman Jim Kennelly said.

Currently, Hudson County has the lowest vaccination rate of any county in the state with 16 doses administered per 100 people. And that has not gone unnoticed by New Jersey Sen. Robert Menendez, who has urged Murphy to take more steps to get residents there vaccinated.

“With 672,000 residents, Hudson is the fourth-most populous county in the State, yet is tenth in the total number of vaccine doses administered,” Menendez wrote in a letter to Murphy on Monday. “Other counties have a rate as high as 33 doses administered per 100 residents. I am deeply concerned that Hudson County residents do not have equitable access to covid-19 vaccinations.”