In April, more than 1,000 vaccine experts gathered in Washington, D.C. for the first time since the pandemic began. Over four days, scientists, doctors and drugmakers pored over cutting-edge research and tackled some of the most pressing questions in the world of vaccines.
Talk of Covid-19 vaccines was, of course, unavoidable. But high on the agenda at the World Vaccine Congress was a vaccine for another mysterious illness that could strike at any moment: Disease X.
Disease X is not any particular virus, bacteria or other germ, but a term used as a stand-in for whatever pathogen will sweep the globe in the next pandemic. And there will indeed be a next pandemic, experts say.
For the vaccine experts, one thing is clear: No matter the form Disease X takes, they'll be called on to get to work and develop the vaccine.
Such a task could feel insurmountable, given the vast unknowns. Should they focus on particular viruses now to get a head start? Should they look at pathogens that so far are found only in animals, but could someday spill over into humans and cause widespread disease, like Covid did?
Big and important questions, yes, but simple enough for this group of vaccine researchers and developers. They know the science. They understand how viruses evolve and spread. They know how to make safe and effective vaccines against them.
But — as has become evident more than a year and a half into the U.S. vaccination campaign — one essential piece of information is missing: How to convince hesitant people to be vaccinated.
"There's something about human behavior that we're still not really understanding," Dr. Nicole Lurie, U.S. director of the Coalition for Epidemic Preparedness Innovations, told the World Vaccine Congress.
Since the first shots went into arms in December 2020, just over 66 percent of the U.S. population is now fully vaccinated, according to the Centers for Disease Control and Prevention.
"There's all this emphasis on science and labs. It's one thing to do that, but it's a whole other thing to get what you develop in the lab into people's arms," said Richard Carpiano, a public health scientist who studies issues surrounding vaccine uptake at the University of California, Riverside.
Scientists at the World Vaccine Congress acknowledged that, for all of their education and training, one issue has remained frustratingly hard to overcome: the growing anti-vaccine movement.
U.S. Surgeon General Vivek Murthy told NBC News that there is no doubt that vaccine misinformation is harming Americans, and could be detrimental in years to come.
"It's certainly one of the issues we must address to prepare for the next pandemic, whenever that may come," he said. "This is absolutely critical from an emergency preparedness standpoint."
If people are refusing vaccines in the face of an ongoing pandemic, widespread deaths will occur in future pandemics, warned Dr. Julie Morita, executive vice president of the Robert Wood Johnson Foundation.
"If we continue to have poor acceptance of vaccines, we will see millions of lives lost in the case of another pandemic as big as this one," she said.
Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children's Hospital and dean of the National School of Tropical Medicine at the Baylor College of Medicine in Houston, addressed conference attendees, saying, "If you really want to save lives, it's not only about making vaccines."
"We continue to underestimate what I call anti-vaccine, anti-science aggression," he said, adding that until it's met head-on, "this will continue to haunt us."
The World Health Organization named vaccine hesitancy one of the top 10 threats to global health in January 2019 — nearly a year before whispers of a mysterious illness in Wuhan, China. The reasons why people may be reluctant or refuse vaccines are complex, the WHO wrote, but include complacency and a lack of confidence in the shots or their health officials. The agency estimated that 1.5 million lives could be saved globally if vaccines were more widely accepted.
What's happened in the U.S. during the Covid pandemic is a prime example of the deadly toll that can occur that can accompany vaccine hesitancy. The Kaiser Family Foundation estimates that nearly a quarter million Covid deaths from June 2021 through March 2022 were among the unvaccinated. This represents 60 percent of Covid deaths reported in that time period.
But vaccine hesitancy is not new. People have been questioning vaccines since they were first introduced in the 18th century to combat smallpox, which, at the time, was killing up to half a million people a year in Europe alone.
In 1910, Canadian physician Dr. William Osler wrote that he remained resolute in the benefits of smallpox vaccinations, despite anti-vaccine sentiments of the time.
"I do not see how anyone who has gone through epidemics as I have, or who is familiar with the history of the subject, and who has any capacity left for clear judgment, can doubt its value," Osler wrote. The New England Journal of Medicine later published his writings.
He went a step further and offered to take 20 people — half of them vaccinated and the other half unvaccinated — into a smallpox outbreak, predicting that half of those who refused the vaccines would ultimately die. "I will make this promise — neither to jeer nor to jibe when they catch the disease, but to look after them as brothers," Osler wrote. "And for the four or five who are certain to die, I will try to arrange the funerals with all the pomp and ceremony of an antivaccination demonstration." (It's unclear, however, whether anyone took Osler up on his offer.)
Over the ensuing century, doctors largely dismissed anti-vaxxers as extremists — even as small pockets of unvaccinated children began to emerge in the early 2000s in certain parts of the country, driven by misinformation about the measles, mumps and rubella, or MMR, vaccine.
It's only been in recent months, as hundreds of thousands of Americans have died of Covid — despite the availability of vaccines — that a growing number of physician scientists have become vocal about vaccine hesitancy, and acknowledged that they need to heed Osler's early warnings.
Dr. Francis Collins, the former head of the National Institutes of Health, admitted on MSNBC in late 2021 that he and other scientists "underestimated the vaccine hesitancy issue."
"We were so totally devoted to getting the best science brought forward and to make sure these vaccines were safe and effective," Collins said. He and other scientists were convinced that, despite some hesitations, people would "come around" especially as the benefits of vaccinations became clear.
It was a clear example of the disconnect between scientists and many laypeople.
"This is a very American thing, this idea that technology will always save us," Carpiano of UC Riverside said. "It's a very TED Talk, Silicon Valley, 21st century kind of way of thinking: just build this tech or invest in it, and our lives are going to be automatically made better."
Even a senior adviser to the Food and Drug Administration's division of vaccines, Dr. Kirk Prutzman, was caught off guard.
"I was genuinely shocked that there's been so much pushback," Prutzman told the World Vaccine Congress. He acknowledged that it's not enough for the FDA to simply make sure vaccines are safe and effective.
"One of the things that we're gonna have to deal with moving forward is the messaging after approval," he said, referring to how the FDA and other health authorities communicate vaccine effectiveness, and help them weigh the shots' risks and benefits.
Who isn't getting their shots?
Part of improving the messaging means knowing the audience.
The Kaiser Family Foundation has been surveying people about their vaccine stances throughout the pandemic, and has found that the biggest factor that determined whether a person would get vaccinated against Covid was politics, said Cynthia Cox, the organization's vice president. (Other factors included lack of access and fear, the latter of which was often influenced by misinformation.)
"A disproportionately large share of the people who are unvaccinated and the people who are dying live in very conservative parts of the country," Cox said.
NBC polling has shown similar results. As of last August, 91 percent of surveyed adults who voted for President Joe Biden in the 2020 election said they were vaccinated, compared with 50 percent who voted for former President Donald Trump.
Therein lies the uncomfortable part for these scientists who tend to prefer data over drama. Addressing vaccine hesitancy and refusal means getting "messy," Hotez said. "It means talking about Republicans and Democrats and liberals and conservatives."
Moving to stop misinformation
Last year, Surgeon General Murthy called on tech companies to do more to take on users spreading inaccurate and misleading vaccine information.
"Misinformation has been around for a long time. What's different now is the speed, the scale and the sophistication with which it is spreading," Murthy said.
Anti-vaccine groups are brilliant manipulators who use social media platforms to stoke fear, especially among parents. They spread graphic, visceral videos of children who seemingly go from happy and healthy to screaming in agony following, these unverified videos allege, an inoculation.
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Murthy formally requested that tech companies with major search engines and social media platforms provide detailed information about how widespread vaccine information is on their sites. The deadline for companies to submit the data was Monday.
Such work is critical to protect Americans against future pandemics, Murthy said.
"Addressing health misinformation is a core part of pandemic preparedness," he said. "If we don't address this crisis, we will be unable to effectively get the treatments and vaccines and help to people who need that help. And that will mean that there will be needless suffering and loss of life that we've sadly seen with Covid."
Other organizations are taking steps to learn more about how to work with people who have been victims of anti-vaccine misinformation.
The WHO released a toolkit for physicians to counter anti-vaccine sentiments, and to promote the safety and benefits of the shots. Johns Hopkins in Baltimore is also leading a national coalition of scientists to better understand why some people refuse to get vaccines.
Dr. Greg Poland, director of the Mayo Clinic Vaccine Research Group in Rochester, Minnesota, suggested that teaching people early in life about the scientific method should be a hallmark of such initiatives.
"We failed the anti-vaxxers," Poland said. "People are not taught probabilities. They're not taught about critical thinking. They've not really been taught biology."
Carpiano, the public health scientist at the University of California, Riverside, agreed. "The pandemic has really shown that there needs to be more efforts on public education around the scientific process — what scientists do, how science even works," he said.
"Changing and revising thoughts about something when new data comes in is not an indicator that we don't know what we're doing."