Americans have made no secret of their skepticism about Covid-19 vaccines, with fears of political interference and a "warp speed" timeline blunting confidence in the shots. As recently as September, nearly half of U.S. adults said they didn't intend to be inoculated.
But with two promising vaccines primed for release, likely within weeks, experts in ethics and immunization behavior say they expect attitudes to shift quickly from widespread hesitancy to urgent, even heated demand.
"People talk about the anti-vaccine people being able to kind of squelch uptake. I don't see that happening," Dr. Paul Offit, a vaccinologist with Children's Hospital of Philadelphia, told viewers of a recent JAMA Network webinar. "This, to me, is more like the Beanie Baby phenomenon — the attractiveness of a limited edition."
Reports that vaccines produced by the drugmakers Pfizer and BioNTech and Moderna appear to be safe and effective, along with the deliberate emphasis on science-based guidance from the incoming Biden administration, are likely to reverse uncertainty in a big way, said Arthur Caplan, director of the division of medical ethics at New York University School of Medicine.
"I think that's going to flip the trust issue," he said.
Full coverage of the coronavirus outbreak
The shift is already apparent. A new poll by the Pew Research Center found that by the end of November, 60 percent of Americans said they would get a vaccine for the coronavirus. This month, even as a federal advisory group met to hash out guidelines for vaccine distribution, a long list of advocacy groups — representing home-based health workers and community health centers to patients with kidney disease — were lobbying state and federal officials in hope that their constituents would be prioritized for the first scarce doses.
"As we get closer to the vaccine being a reality, there's a lot of jockeying, to be sure," said Katie Smith Sloan, chief executive of LeadingAge, a nonprofit organization pushing for staff members and patients at long-term care centers to be in the highest-priority category.
We're going to have some fights about high-risk groups.
Certainly, some consumers remain wary, said Rupali Limaye, a social and behavioral health scientist at the Johns Hopkins Bloomberg School of Public Health. Fears that drugmakers and regulators might cut corners to speed a vaccine linger, even as details of the trials become public and the review process is made more transparent. Some health care workers, who are at the front of the line for the shots, aren't eager to go first.
"There will be people who will say, 'I will wait a little bit more for safety data,'" Limaye said.
But the doubts likely will recede once the vaccines are approved for use and begin to circulate broadly, said Offit, who is on the Food and Drug Administration advisory panel that is set to review the requests for emergency authorization that Pfizer and Moderna have submitted.
'How can I get the vaccine?'
Offit predicted that demand for the vaccines could rival the clamor for flu shots in 2004, when production problems caused a severe shortage just as influenza season began. That led to long lines, rationed doses and ethical debates about distribution.
"That was a highly desired vaccine," Offit said. "I think in many ways that might happen here."
Initially, vaccine supplies will be tight. Federal officials plan to ship 6.4 million doses within 24 hours of FDA authorization and up to 40 million doses by the end of the year. A panel of the Centers for Disease Control and Prevention recommended that the first shots go to the 21 million health care workers in the U.S. and to 3 million nursing home staff members and residents before it is rolled out to other groups based on a hierarchy of risk factors.
Even before any vaccine is available, some people are trying to boost their chances of access, said Dr. Allison Kempe, an expert in vaccine dissemination who is a professor of pediatrics at the University of Colorado School of Medicine. "People have called me and said, 'How can I get the vaccine?'" she said. "I think that not everyone will be happy to wait, that's for sure. I don't think there will be rioting in the streets, but there may be pressure brought to bear."
That is likely to include emotional debates over how, when and to whom the next doses should be distributed, Caplan said. Under the CDC recommendations, those next in line include 87 million workers whose jobs are deemed "essential" — a broad and ill-defined category — as well as 53 million adults ages 65 and older.
"We're going to have some fights about high-risk groups," Caplan said.
Download the NBC News app for full coverage of the coronavirus outbreak
The conversations will be complicated. Should prisoners, who have little control over their Covid-19 exposure, get priority? How about professional sports teams, whose performances could bolster society's overall morale? And what about residents of facilities providing care for people with intellectual and developmental disabilities, who are three times more likely to die from Covid-19 than the general population?
Control over allocating vaccines rests with the states, so that's where the biggest conflicts will occur, Caplan said. "It's a short fight, I hope, in the sense in which it gets done in a few months, but I think it will be pretty vocal."
Once supplies become more plentiful, perhaps by May or June, another consideration is sure to boost demand: requirements for proof of vaccination for work and travel.
"It's inevitable that you're going to see immunity passports or that you're required to show a certificate on the train, airplane, bus or subway," Caplan said. "Probably also to enter certain hospitals, probably to enter certain restaurants and government facilities."
But with a grueling winter surge ahead and new predictions that Covid-19 will kill as many as 450,000 people in the U.S. by February, the tragic reality of the disease will no doubt fuel ample demand for vaccination.
"People now know someone who has gotten Covid, who has been hospitalized or has unfortunately died," Limaye said.
Kempe said: "We're all seeing this now. Even deniers are beginning to see what this illness can do."
Follow NBC HEALTH on Twitter & Facebook