WASHINGTON (NYTIMES) - Almost daily, US President Donald Trump and leaders worldwide say they are racing to develop a coronavirus vaccine, in perhaps the most urgent mission in the history of medical science.
But the repeated assurances of near-miraculous speed are exacerbating a problem that has largely been overlooked and one that public health experts say must be addressed now: persuading people to actually get the shot.
A growing number of polls find so many people saying they would not get a coronavirus vaccine that its potential to shut down the pandemic could be in jeopardy.
Distrust of it is particularly pronounced in African American communities, which have been disproportionately devastated by the virus.
But even many staunch supporters of immunisation say they are wary of this vaccine.
"The bottom line is I have absolutely no faith in the FDA (Food and Drug Administration) and in the Trump administration," said Ms Joanne Barnes, a retired fourth-grade teacher from Fairbanks, Alaska, who said she was otherwise always scrupulously up to date on getting her shots, including those for shingles, flu and pneumonia.
"I just feel like there's a rush to get a vaccine out, so I'm very hesitant."
Mistrust of vaccines has been on the rise in the US in recent years, a sentiment that resists categorisation by political party, educational background or socioeconomic demographics.
It has been fanned by a handful of celebrities.
But now, anti-vaccine groups are attracting a new type of clientele altogether.
Ms Jackie Schlegel, founder of Texans for Vaccine Choice, which presses for school vaccine exemptions, said that her group's membership had skyrocketed since April.
"Our phones are ringing off the hook with people who are saying, 'I've got every vaccine, but I'm not getting this one,'" she said.
"'How do I opt out?'"
She said she often has to assure callers: "'They're not coming to your home to force-vax you.'"
The fastidious process to develop a safe, effective vaccine typically takes a decade; some have taken far longer.
But the administration of Mr Trump, himself once an outspoken vaccine sceptic, has been saying recently that a coronavirus vaccine could be ready this fall.
While it has removed certain conventional barriers, such as funding, many experts still believe that the proposed timeline could be unduly optimistic.
But whenever a coronavirus vaccine is approved, the assumption has been that initial demand would far outstrip supply.
The need to establish a bedrock of confidence in it has largely been overlooked and unaddressed.
Earlier this month, a nationwide task force of 23 epidemiologists and vaccine behaviour specialists released a detailed report - which itself got little attention - saying that such work was urgent.
Operation Warp Speed, the US$10 billion (S$13.8 billion) public-private partnership that is driving much of the vaccine research, they wrote, "rests upon the compelling yet unfounded presupposition that 'if we build it, they will come'".
In fact, "if poorly designed and executed, a Covid-19 vaccination campaign in the US could undermine the increasingly tenuous belief in vaccines and the public health authorities that recommend them - especially among people most at risk of Covid-19 impacts", wrote the group led by researchers at the Johns Hopkins Centre for Health Security and the Texas State University anthropology department.
The researchers noted that although billions of federal dollars were pouring into biomedical research for a vaccine, there seemed to be virtually no funding set aside for social scientists to investigate hesitancy around vaccines.
Focus groups to help pinpoint the most effective messaging to counter opposition, the authors said, should get under way immediately.
The current political and cultural turbulence, abetted by the Trump administration's frequent disregard for scientific expertise, is only amplifying the diverse underpinnings of vaccine-sceptic positions.
They include the terrible legacy of federal medical experiments on African Americans and other disadvantaged groups; a distrust of Big Pharma; resistance to government mandates like school immunisation requirements; adherence to homeopathy and other "natural" medicines; and a clutch of apocalyptic beliefs and conspiracy theories particularly around Covid-19, sometimes perpetuated by celebrities, most recently Kanye West.
"It's so many of our children that are being vaccinated and paralysed," he told Forbes this month.
"So when they say the way we're going to fix Covid is with a vaccine, I'm extremely cautious. That's the mark of the beast."
A poll in May by The Associated Press-Norc Centre for Public Affairs Research found that only about half of Americans said they would be willing to get a coronavirus vaccine.
One in five said they would refuse and 31 per cent were uncertain.
A poll in late June by researchers at the University of Miami found that 22 per cent of white and Latino respondents and 42 per cent of Black respondents said they agreed with this statement: "The coronavirus is being used to force a dangerous and unnecessary vaccine on Americans."
"The trust issues are just tremendous in the Black community," said Ms Edith Perry, a member of the Maryland Community Research Advisory Board, which seeks to ensure that the benefits of health research encompass Black and Latino communities.
The solution, she said, is not just to employ the conventional strategy of meeting with black church congregations, especially if the government and vaccine producers want to reach millennials.
"The pharmaceutical industry would have to convince some of the young people in Black Lives Matter to get on board," Ms Perry said.
"Throw up your hands and say, 'I apologise. I know we did it wrong and I need your help to get it right.' Because we need a vaccine and we need black and Hispanic participation."
The chatter at The Shop Spa, a large barbershop with a Black and Latino clientele in Hyattsville, Maryland, underscores the challenges.
Mr Mike Brown, the manager, whose staff members have been trained to talk up wellness with clients, referred to the notorious Tuskegee experiments, and said: "I hope they don't sabotage us again."
His clients and their families are still leery of drug companies, he said.
"It's hard to trust that they're looking out for our well-being," he continued.
"Me, I'm very sceptical about that shot. I have my popcorn and my soda and I'm just watching it very carefully."
The new report on vaccine confidence includes input from epidemiologists and experts in health inequities and communication.
The overarching recommendation is that public health agencies should listen to community concerns early in the process, rather than issuing them directives from on high after the fact.
They should seek out trusted community leaders to convey people's uncertainties around research transparency, access, allocation and cost.
Those representatives could, in turn, become respected purveyors of updates, to combat what the World Health Organisation calls the "infodemic" of vaccine misinformation.
The strongest recommendations were about communities of colour.
The authors urged that vaccines be provided for free and made available at easy access neighbourhood locales: churches, pharmacies, barbershops, schools.
Noting that the vaccine would be emerging at a time when protests about systemic racism, not least in health care, have been erupting, the researchers cautioned that if accessibility was perceived to be unfair, the vaccine could become a flash point of continuing unrest.
And that perception could heighten mistrust of the vaccine.
At a recent Senate hearing, Dr Robert Redfield, director of the Centres for Disease Control and Prevention, was asked repeatedly about plans to address surging vaccine hesitation.
He replied that discussions had been under way for "10 to 12 weeks".
A spokesman for the CDC declined to elaborate after being asked repeatedly by The New York Times to do so.
Associate Professor Emily Brunson, a medical anthropologist at Texas State University, said that the myriad number of reasons people may be sceptical of this vaccine, combined with the vast, unsparing reach of Covid-19 itself, meant that creating a campaign for the vaccine's acceptance would be far more difficult than one for a more narrowly defined group - shingles vaccine for older people, HPV vaccine for pre-teens.
The researchers said that a national promotional strategy should be in the planning stages as soon as possible.
Overall, the worry that is consistently invoked by those hesitant about this vaccine is haste.
When the health authorities repeatedly tout the rapidity of development - an idea underscored by the name Operation Warp Speed - they inadvertently aggravate the public's safety concerns.
"If you're smart, you're worried we won't have a vaccine, and if you're smart, you're worried that maybe we've moved so fast that we'll accept a level of risk that we might not ordinarily accept," said Professor Sandra Crouse Quinn, a public health expert at the University of Maryland.
Health communication experts say that those trying to persuade the vaccine-hesitant to be immunised should not dismiss them as "anti-vaxxers", which has become an insult and shuts down conversations.
"You always have to listen to their concerns," said Prof Quinn, the senior associate director of the Maryland Centre for Health Equity, who studies issues around healthcare trust in communities of colour.
Last week, a non-profit public health initiative, the Public Good Projects, introduced Stronger, a campaign to combat vaccine misinformation, with a plethora of tips, including lists of established scientists to follow on Twitter.
One path toward increasing the acceptance of the vaccine, Prof Quinn said, is to appeal to people's innate altruism. "That getting a vaccine, when it's available, is not just about you. It's about protecting your grandmother who has diabetes and Uncle Sean, who is immune-compromised," she said.
And when people respond by listing their objections to the vaccine, ask them, she said: "If that's what you think, then how do you protect your community?"