WASHINGTON (NewsNation Now) — With the Biden administration sending a flood of vaccines to the states, getting enough people vaccinated to reach herd immunity is closer than ever.

The nation’s top infectious diseases expert, Dr. Anthony Fauci, said herd immunity may require vaccination rates approaching as high as 90%. About 64.42 million people, or 19.4% of the U.S. population, have been fully inoculated with COVID-19 vaccines made by Pfizer Inc/ BioNTech SE, Moderna Inc and Johnson & Johnson, according to CDC data.

The United States is now leading the world in vaccine distribution, averaging more than 3 million shots a day but some groups are resisting more than others, specifically evangelical Christians, according to a new poll.

Lauri Armstrong is a wife, mother, nutritionist and Christian in Texas. “I think it’s a really personal choice,” said Armstrong. “My decision to not vaccinate has a lot to do with science and my faith.”

Only 54% of white evangelical Christians say they will get a vaccine, making them the religious group least likely to get vaccinated, according to data compiled by the Pew Research Center.

With resistance threatening to delay the moment when life returns to normal, some evangelical leaders are pushing back, framing the vaccine in terms that may appeal to the devout.

“This vaccine is an opportunity to love our neighbors,” said Kent Annan Co-Director of the Humanitarian Disaster Institute.

They say the question of whether to get a vaccine breaks along familiar political lines.

“It’s becoming almost a sign of tribalism in the same way that there was this divide of, well if you wear a mask or you don’t wear a mask, this must be the group that you belong to,” said Jamie Aten, founder and director of the Humanitarian Disaster Institute. “And I think we’re seeing some of that play out now with the vaccine as well.”

Not all Republicans are hesitant. The party’s top elected official, Senate Minority Leader Mitch McConnell, is urging his base to get the shot.

“I’m a Republican man and I took it soon as I was eligible,” McConnell said. “Whatever you have seen on social media, whatever rumors you may have heard, the facts are: these vaccines work.”

Congress and the Biden administration will spend $10 billion dollars on better access to vaccines and building confidence around them. House Speaker Nancy Pelosi Wednesday said it’s “imperative” Americans know the vaccine is safe and backed by science.