Doctors and nurses, coping with the daily risk of coronavirus exposure, are expected to get top priority to receive vaccines that could become available as soon as next month. But it’s an open question how many will seize their place at the front of the line.

Large health systems, medical societies and the federal government are launching an effort to persuade front-line health-care providers to take novel vaccines that were developed, and are likely to be granted emergency approval, in record time.

In Boston, major teaching hospitals are rolling out educational videos aimed at assuring medical staff the process of developing coronavirus vaccines will result in safe and effective shots. At New York’s Mount Sinai Health System, a leading infectious-disease doctor said he probably will distribute photos of himself getting a shot in a bid to build confidence among front-line staff.

Hospitals in urban areas are taking additional measures to make sure ethnic and racial minority members, who form a large percentage of their front-line nursing and support staffs, receive rapid information about the safety and effectiveness of the new vaccines.

Winning buy-in from doctors and nurses is crucial to gaining broader public support for the vaccines, based on the high degree of trust placed in them by patients. The hesitancy of some health-care workers is attracting attention as the first two vaccines, from Pfizer and Moderna, near deployment. Pfizer and its partner, BioNTech, filed their Food and Drug Administration application for emergency use on Friday.

Polling last month showed that 58 percent of U.S. adults were willing to get vaccinated against the coronavirus. A Pew Research Center poll in September found 51 percent of Americans said they would definitely or probably get a coronavirus vaccine.

Medical experts said attitudes among doctors, nurses and the public could shift quickly as new data are revealed. But government, academic, and health-care officials say that significant numbers of providers want more data about the vaccine before it is deployed. Some of the information is expected to be released next month by the FDA.

A report released Thursday by the University of California at Los Angeles researchers said that 66 percent of Los Angeles health-care workers who responded to an online questionnaire (not a randomized sample) said they would delay taking a vaccine. The American Nurses Association, a national professional organization, said one-third of its members do not intend to take the vaccine, and an additional third are undecided.

New Jersey said last week that its data showed that 66 percent of the state’s doctors planned to receive the vaccine. Among professionals contacted by the state, “some did not want to be in the first round, so they could wait and see if there are potential side effects,” New Jersey Health Commissioner Judith M. Persichilli said at a Nov. 9 news briefing.

“Of those who said they would not take the vaccine, many said they would be more than willing to get the vaccine at a later date, when more data is available,” she said.

The hesitancy among doctors and nurses is not the same as the anti-vaccine movement, which medical experts consider a fringe trend fueled by misinformation and conspiracy theories on social media. Health professionals tend to be advocates of vaccines, including seasonal flu shots, shingles vaccines, and childhood inoculations for measles, mumps and rubella.

But in the case of the coronavirus shots, health-care leaders say President Trump’s frequent promises about vaccines have raised doubts about the objectivity of agency reviews, as have the speed of the manufacturers’ clinical trials, and unfamiliarity with the novel techniques used by the Pfizer and Moderna vaccines to trigger natural antibodies.

“We are vaccines’ greatest champions, but this is the first time that a new vaccine has been developed at a rapid pace in the middle of a pandemic, as opposed to a much longer timeline,” Susan Bailey, a physician in Fort Worth and president of the American Medical Association, said in an interview.

“What I hear from physicians is some of the same concerns that are expressed by everyone. They worry the process has been politicized. They are concerned because they haven’t seen any published data yet. And they don’t feel comfortable making the decision one way or another until they see the evidence,” Bailey said.

Medical professionals are “the most trusted source for health information,” the Centers for Disease Control and Prevention said late last month during a meeting to discuss national distribution plans. “Concerns among health-care providers is a risk for overall vaccine confidence.” The CDC did not respond to a request for comment.

After the fastest development ever, the FDA could grant emergency authorization for the two vaccines as soon as next month. That would begin an immediate push to vaccinate 20 million people before the end of the year and hundreds of millions in 2021.

Health professionals must quickly learn the science behind a pair of mRNA vaccines that work differently from traditional vaccines and will need to help convince the public that the vaccines are safe and effective, said Howard Koh, a professor at the Harvard T.H. Chan School of Public Health and a U.S. assistant secretary of health during the Obama administration.

“A doctor who can’t commit to a vaccine personally may find it difficult, if not impossible, to advise their patients to do so,” he said.

“Operation Warp Speed — just that name connotes urgency and timeliness, but could bring to mind for many a fear of the process being rushed,” Koh said. “And we have seen the administration contradicting their own top public health officials and trying to accelerate a process that we know has to be done with all deliberate speed.”

Pfizer and Moderna have provided data from their large-scale Phase 3 trials only via news releases, which contained the highly promising news that both vaccines were 90 percent effective or more and have not presented any serious safety concerns.

Bailey, Koh and other leaders said it is crucial for the companies to publish full trial results as soon as possible to win approval from physicians.

In coming weeks, the FDA and the companies will be analyzing data from the trials in more detail. The agency has said it will require two months of follow-up safety analysis in trial participants before it will consider issuing emergency-use authorizations — still much faster than the typical minimum follow-up of six months. An FDA committee of independent advisers also will review available efficacy and safety evidence in a public hearing before the EUA is issued. Pfizer did not respond to requests for comment. Moderna said it plans to release more data that should satisfy concerns.

“We believe that transparency with respect to mRNA-1273 scientific results (especially as increasing amounts of data become available) will be the strongest antidote over time to individual uncertainties or anxieties,” Ray Jordan, Moderna’s chief corporate affairs officer, said in an email. “We expect to publish results in peer-reviewed journals as data sufficiently mature over time, just as we have with the multiple evaluated outcomes from our Phase I trial.”

Bailey, the AMA president, said that as an allergist and immunologist, she frequently receives questions about the new vaccines.

“When my patients ask me, I say once I’ve seen the studies and feel confident that no corners have been cut, and no steps have been skipped, and we have a safe and effective vaccine, I’ll be the first in line,” she said.

In an AMA video released Nov. 2, Bailey said the number of physicians expressing hesitancy was “unprecedented” and said it posed “real risk” to public confidence in vaccines. Since the video was released, Trump was defeated in his bid for a second term, and Pfizer and Moderna reported that their vaccines worked in more than 90 percent of people who received them.

Once full data sets are available, if they show a sound safety profile, doctors will come around, Bailey said in an interview. “Most of us are not sitting around reading journals right now. We’re literally trying to save lives,” she said, “but when that data is available, I think the uptake will be quite rapid.”

At the Association of American Medical Colleges, Chief Scientific Officer Ross McKinney said many questions remain about the effectiveness of the vaccines, and how long immunity will last. But the promising Pfizer and Moderna results, plus the outcome of the presidential election, will rapidly shift the landscape, he predicted.

“We’re past November 3rd, and the perception that the vaccine was being force-fed for an election win is no longer an issue,” McKinney said. “I suspect you are going to see very different numbers on hesitancy. I think you are going to see a huge change in the perceived reluctance to get vaccinated.”

The CDC said 98 percent of doctors and 92 percent of nurses were vaccinated for influenza during last winter’s flu season. Many hospital systems mandate staff receive flu shots, but similar directives are not expected for coronavirus vaccines — at least not immediately — because they will still be considered experimental.

Introducing new vaccines is not easy during a global health emergency and a national political debate stoked by a president known to frequently distort, discredit and make false claims about science. The national pandemic response has been marked by emotional and confusing political battles.

In New York, Gov. Andrew M. Cuomo (D) formed his own panel of experts to review vaccines that are authorized by the FDA, saying in September, “I’m not going to trust the federal government’s opinion, and I wouldn’t recommend to New Yorkers based on the federal government’s opinion.” Trump responded by saying that the federal government will not send a coronavirus vaccine to New York when it becomes available.

The president repeatedly promised during his reelection campaign that a vaccine would be approved for the United States before the Nov. 3 election. That did not happen. Now, convincing Americans and the medical community that the first vaccines are safe and effective will fall to Trump’s lame-duck administration and then to President-elect Joe Biden.

“These mRNA vaccinations have never been approved before, so there is no reliable track record of safety. We should expect to set the bar higher for safety,” said Jeffrey A. Hirschfield, a pediatrician in St. Petersburg, Fla., who has discussed his reservations on Twitter. “It typically takes five to 10 years to successfully develop and vet vaccine candidates, especially those relying on new technologies.”

Marie Ritacco, a longtime nurse at St. Vincent Hospital in Worcester, Mass., and vice president of a state nurses union, said many nurses will continue to rely on personal protective equipment and strict anti-infection procedures rather than be in the first wave of health-care workers receiving coronavirus vaccines.

“I’m not an anti-vaxxer. I believe in vaccinations. But I’ve never seen a process this fast,” she said. “I don’t think we have enough data to show that it is safe, will not cause harm and will be highly effective. We drive all these decisions on data, and the data is just not there yet.”

Vaccines that use mRNA, or messenger RNA, work by carrying a genetic message into the body that signals cells to produce the novel coronavirus’s distinctive spike protein, triggering an immune response that creates specific antibodies. Traditional vaccines depend on inactivated virus to accomplish that mission, or some use a viral vector such as a harmless cold virus engineered to contain the genetic instructions for the spike protein.

Health systems nationwide are preparing to distribute the vaccine, and some are beginning to prepare their workforces.

Marci Drees, the infection prevention officer and hospital epidemiologist at ChristianaCare, a hospital system based in Wilmington, Del., said rank-and-file workers will need to be reassured about the safety and efficacy of a vaccine from within their own systems. Guidance from the CDC and the FDA will be helpful, but faith in government reviews has been shaken and cannot be the sole source of information, she said.

“A lot of it will be on the ground level, because there has been so much distrust in general,” Drees said. “Being very transparent about what we know, and what we don’t know, is really important.”

She said she receives frequent questions from ChristianaCare medical staff about the two-month safety follow-up window that the FDA is relying on to assess the risk of adverse events.

“We are not going to have long-term safety data on these vaccines, but we do know that most side effects occur within the first few weeks after vaccination,” so the FDA’s two-month threshold should give people confidence, Drees said.

In Boston, the large Mass General Brigham health system, which encompasses large academic medical centers including Massachusetts General Hospital and Brigham and Women’s Hospital, as well as community hospitals, has produced videos for its 80,000 employees.

The videos feature assurances from some of the system’s physicians that a vaccine will not be released unless it is known to be safe after thorough reviews by FDA scientists, as well as those outside the government who serve on independent advisory committees.

“We know there are concerns about whether politics played a role in vaccine approval, and we wanted to clearly communicate that there are independent groups that participate in the process that we trust and respect,” said Paul Biddinger, a Mass General physician and the director of emergency preparedness for the broader Mass General Brigham system.

Academic medical centers are expected to be the earliest sites for distribution of mRNA vaccines because they have enough of the ultracold freezers required for their storage, as well as research scientists who can help interpret clinical trial data for their communities.

It is vital that physicians and nurses at these institutions show that they are willing to take the vaccines first, not just to reduce the spread of the coronavirus in a high-risk environment, but also to demonstrate to the community that they stand behind the vaccines, Biddinger said.

That is especially true for vulnerable groups that have been hit hardest by the coronavirus, including African Americans, he said, who may mistrust the U.S. health-care system, given historical examples of unethical medical experiments that targeted Black people and caused harm.

Initial scarcity of supply will result in a gradual escalation of experience with the vaccines. By the time hundreds of millions of doses are available for everyone in the nation, Biddinger said, health systems should be ready to strongly recommend they be used more broadly.

“We think it will snowball with increasing availability of product,” he said, “and people can look back, and we can say we have vaccinated hundreds of thousands, millions of people, and we have not seen adverse events, and therefore we should do this because we want to save lives and get us out of the pandemic.”

At Mount Sinai in New York, Bernard Camins, an infectious-disease doctor who is Mount Sinai’s director of prevention and is helping coordinate the hospital system’s vaccine distribution, said the coronavirus vaccination for medical workers will be modeled on efforts to push the annual influenza vaccine.

“I’m surprised considering how bad this pandemic has been that [vaccine hesitancy] is equivalent to 50 percent” among Mount Sinai health care staff, Camins said during a webinar Thursday sponsored by national health-care provider EHE Health, calling that a “pessimistic” estimate based on his anecdotal conversations. “Unfortunately, it’s the mixed messages they have gotten.”

Correction: An earlier version of this story incorrectly described the American Nurses Association as a union. It is a professional organization. The story has been updated.