As the delta variant of the coronavirus spreads, especially among the unvaccinated, the Biden administration is gearing up for a new push to vaccinate the so-called "movable middle"—and some public health experts say FDA could advance that goal by fully approving Covid-19 vaccines.

Should you mandate a Covid-19 vaccine for your staff? Ask these 5 questions first.

Analysis reveals toll of US Covid-19 deaths among unvaccinated patients

According to an analysis by the Associated Press, nearly all recent Covid-19 deaths have occurred in unvaccinated individuals.

The AP analysis is based on data from CDC, although CDC has not itself released estimates of the share of Covid-19 deaths among unvaccinated patients.

According to the AP analysis, just 0.8% of Covid-19 deaths in May were among the fully vaccinated. Meanwhile, the share of hospitalized patients who were fully vaccinated was just 0.1% in May, with fewer than 1,200 fully vaccinated people hospitalized out of more than 853,000 hospitalizations.

Meanwhile, according to CDC, 54% of the U.S. population, including 66% of American adults, have received at least one dose of a Covid-19 vaccine, while 46.1% of the total population and 56.8% of American adults have received all required doses.

Biden administration pushes to reach the 'movable middle'

As the delta variant spreads, the Biden administration has begun a new push to reach Americans who are not yet vaccinated but who are open to persuasion—a group of roughly 55 million Americans health officials refer to as "the movable middle."

"We're not just going to do the mass vaccination sites," HHS Secretary Xavier Becerra said. "It's door to door. It's mobile clinics. We're doing vaccinations at church, the PTA meeting, the barber shop, the grocery store."

Three senior administration officials told Politico the administration had considered pushing mayors and governors in states where the delta variant is quickly spreading to reinstitute mask mandates, but determined those resisting vaccination are also those who have resisted mask mandates.

Instead, the officials said the administration plans to work with local leaders and community members to encourage people to get vaccinated. The officials told Politico the Biden administration intends to put more responsibility for getting people vaccinated on local leaders, who can then pass that responsibility on to trusted community leaders.

Cynthia Finch is one of those community leaders, and she said she's been encountering skepticism, especially in minority communities who have had a long history of receiving poor health care. She said she tries to listen to people's concerns and respond with factual information.

"When you start telling them things they can relate to, it kind of calms them down," she said.

Calls for FDA to approve Covid-19 vaccines increase

Meanwhile, some health experts are ramping up calls for FDA to fully approve the Covid-19 vaccines that are currently being distributed under an emergency use authorization.

Writing on Twitter, Ashish Jha, dean of the Brown University School of Public Health, suggested that for some unvaccinated Americans, the fact that vaccines aren't yet fully approved could be a "hindrance" to seeking vaccination. "One thing that might help? An FDA full approval," he wrote.

Jha added, "Data is in. Vaccines are safe and effective. It's time for full approval."

Gigi Gronvall, a senior scholar at Johns Hopkins Center for Health Security, said there shouldn't be "political pressure" on FDA, but added she would "be interested in knowing what the holdup is."

"It could have a big impact on people getting (vaccinated) if it is FDA approved," she said. "I think it's worth asking why it hasn't happened yet."

Arkansas Gov. Asa Hutchinson (R) also said he believes an approval from FDA will lead to more people getting vaccinated and a drop in Covid-19 hospitalizations.

"Whenever they see emergency use authorization, then they say, well, they haven't made a final approval, they haven't got all the research completed that is needed on there. They want to do more study. And so it was approved as emergency use," he said. "And so for that reason, you can't mandate it. We don't mandate it in Arkansas. We have to rely upon the education."

However, Jesse Goodman, a former chief scientist at FDA, said if the agency rushed approval "that will actually have the opposite effect. I think that would really undermine confidence."

Goodman said he believes FDA is doing the right thing with approval so far. "They're moving quickly but they're requiring a careful review," he said, adding that he believes the review could be done within "three or four months" (Lonas, The Hill, 6/25; Banco/Lim, Politico, 6/26; Reyes, Axios, 6/27; Alonso-Zaldivar, Associated Press, 6/27; Johnson/Stobbe, Associated Press, 6/24; Sullivan, The Hill, 6/27; Quinn, CBS News, 6/27).