Erin N. Marcus is a professor of clinical medicine at the University of Miami Miller School of Medicine and a Public Voices fellow.

In January, when covid-19 seemed like a distant threat, I had a patient with the flu. The infection hit her hard; she had to be put on a ventilator and was given intravenous steroids. I took care of her during her long hospital stay after she was released from intensive care. Each day, the resident physicians and I would ask her: “Any thought about getting the vaccines we discussed?”

Every day, the answer was the same: No. We told her that we got the flu shot every year, that her recent illness would have been prevented by the vaccine, that her asthma and other medical problems put her at risk for serious complications from another bout of influenza. It didn’t matter. “I don’t trust shots,” she told us.

I’ve been thinking about this patient a lot recently. She’s the reason I worried when I saw the recent announcement from the Centers for Disease Control and Prevention advising state health departments to plan for distributing a coronavirus vaccine by Nov. 1, less than two months from now. More than a third of people surveyed in a recent Gallup poll said they would refuse a free coronavirus vaccine, even though covid-19 has killed more than 184,000 Americans and caused long-term complications in countless others. A perceived rush by the federal government may only solidify their skepticism — and make it harder to defeat the pandemic.

It’s important to appreciate just how accelerated America’s vaccine timeline is. On average, developing a vaccine takes 10 years. The Trump administration’s “Operation Warp Speed,” by contrast, aims to deliver 300 million doses of a safe, effective covid-19 vaccine by January, only a year after the disease became apparent. While researchers around the world have made heroic efforts to swiftly tame the virus, Phase 3 trials — where vaccine candidates are given to thousands of people to test safety and efficacy — only began in the United States about five weeks ago. It’s unlikely scientists will have adequate results from those trials for vaccine distribution to begin in eight weeks.

And the dangers of moving ahead without sufficient evidence are real. I’m old enough to remember learning about cases of Guillain-Barré syndrome, a debilitating paralysis, that occurred in some people who received the swine flu vaccine in the 1970s. Subsequent versions of the flu vaccine were far safer and, as it turns out, flu infection itself can cause Guillain-Barré. But for decades, many doctors and nurses hesitated to give people flu shots, fearful of the risk. Even now, I find I have to work harder to convince patients to get the flu vaccine compared to shots for tetanus and other diseases.

This is why it’s imperative that the approval process for the covid-19 vaccine be guided by science, not politics or profit. The fact that Peter Marks, the FDA official in charge of vaccine evaluation, has said he’d resign rather than allow an ineffective or unsafe vaccine to be approved is reassuring. But he will likely face an unprecedented amount of pressure from an administration that has frequently avoided putting science first in making policy decisions about the pandemic.

Only a timeline supported by robust medical evidence, combined with transparency about what is happening during Phase 3 trials, can help the government win over the constituency it needs most: health-care providers. Doctors’ recommendations are among the most important factors in people’s decisions to get immunized — and our first obligation is to patients, not politicians. When people ask us whether they should get the covid-19 vaccine, we need to be confident about why we’re answering “yes.”

Even once there is a vaccine that we’re confident is safe and effective, our job convincing patients to get it won’t be easy. This is another area where government can help: messaging tactics. Public-health officials should help guide physicians and nurses on how to communicate effectively about the vaccine, prioritizing emotionally powerful stories about the suffering covid-19 can cause over a fire hose of statistics, which can actually backfire. Language, too, is important: Health workers should avoid “herd immunity,” which conjures up visions of cattle, and instead use “community immunity,” which conveys that we’re all facing this pandemic together.

Officials can also help by modeling good behavior. To engender trust in the vaccine, we need to see our political leaders and their family members rolling up their own sleeves to get it. It will be a disaster if leaders twist receiving — or refusing — the vaccine into a political statement, as was done with mask-wearing.

Achieving mass vaccination against covid-19 will require overcoming barriers that are not just scientific, but also social and psychological. Rushing to “get something done” before Election Day, in the absence of a coherent communications strategy, will just reinforce all three. Honesty, clarity and a responsible timetable are the only ways government can win over health-care providers — not to mention the skeptical patients we’ll need to persuade.

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