On a hot July afternoon in 2004, the anthropologist Heidi Larson perched on a low mud wall in Nigeria, talking with a group of mothers as livestock and children milled about. Public-health workers had been making progress vaccinating thousands of Nigerian children against polio, but rumors that the shots were laced with H.I.V. and infertility drugs had led to a vaccine boycott in several northern states. Larson, who was working for UNICEF’s Global Alliance for Vaccines and Immunization (now known as Gavi), spoke to the women through a Hausa interpreter. “Aside from the vaccine rumors, is there anything else you’re concerned about?” she asked.
Her question unleashed a torrent of answers. The women said they were frustrated by the government’s aggressive efforts on behalf of a single vaccine when their villages lacked reliable drinking water and electricity. They wondered why no one was knocking down their doors to rout diarrheal diseases, poverty, or starvation. They were infuriated by the condescending attitude of public-health officials toward their vaccine concerns; they were still haunted by a clinical trial for a meningitis drug, conducted by Pfizer, eight years earlier, which had left eleven Nigerian children dead and dozens disabled. Amid America’s “war on terror,” some found it entirely plausible that Western countries might be trying to sterilize Muslim children or infect them with H.I.V. Others were eager to vaccinate their kids but forbidden from doing so by their husbands. Larson found that there was no single explanation for their vaccine hesitancy. Instead, their attitudes were filtered through an intricate mix of rumors, mistrust, history, and facts on the ground.
Larson, a professor at the London School of Hygiene and Tropical Medicine, studies vaccine rumors—how they start, and why some flourish and others wither. Public-health experts often address vaccine hesitancy on an informational basis, by debunking rumors and misinformation. But, in her recent book, “Stuck: How Vaccine Rumors Start—and Why They Don’t Go Away,” Larson argues for a more expansive view of the problem. “We should look at rumors as an eco-system, not unlike a microbiome,” she writes. Tackling misperceptions individually is like eliminating a single microbial strain: when one germ is gone, another will bloom. Instead, the entire ecosystem must be rehabilitated.
In 2010, in London, Larson founded the Vaccine Confidence Project, with the goal of putting these ideas into practice. Its analysts—trained in digital media, political science, artificial intelligence, psychology, statistics, epidemiology, and computer science—monitor news sites and social media in more than a hundred languages, then strategize with local health groups about how to tackle the rumors they find. Larson describes the Vaccine Confidence Project as “investigating the global vaccine weather, while zooming in to local storms.” This year, the project has fielded requests for help from health officials in some fifty countries, including, in the few days before one of our phone calls, Sudan, Somalia, Turkey, and Iran. Her team works in an epidemiological spirit, hoping to contain outbreaks of misinformation swiftly, before they can spread.
Larson has also developed a tool for quantitatively mapping vaccine hesitancy: the Vaccine Confidence Index, a set of validated questions concise enough to reach vast populations. In 2015, she posed the questions to sixty-six thousand people in sixty-seven countries—the first time a rigorous survey of vaccine attitudes had been conducted at that scale. Larson’s results took many public-health experts by surprise. The lowest levels of vaccine confidence were found in countries with the highest education levels and the best health-care systems; seven of the ten most vaccine-hesitant countries were within the European Union. (France ranked first.) Global-health efforts tend to focus on poorer countries such as Nigeria, but the results suggested that the ability of vaccines to end pandemics might also be weak in wealthier countries—the same nations that export public-health expertise to the developing world.
Larson, who is sixty-four, has a calming, meditative demeanor that masks a restless intellect. Willowy, with no-nonsense straight hair, she has spent the coronavirus pandemic tracking vaccine attitudes from the home in North London she shares with her husband, the Belgian microbiologist Peter Piot, who helped discover and contain Ebola. Larson and Piot share a vast repository of global-health experience; in March, 2020, they shared the coronavirus. She experienced mild symptoms, but Piot fell seriously ill.
Over a video call this spring, Larson told me that the COVID vaccination effort “should remind everybody that you cannot have scientific advances and great global-health plans” without taking vaccine confidence into account. Five months into the vaccination effort, the share of the U.S. population who’ve received at least one dose of the vaccine has barely exceeded fifty per cent. After reaching a peak of more than four million doses per day in mid-April, the daily number of doses has been falling off, slipping under a million per day in June. Herd immunity through vaccination seems increasingly unlikely. But Larson is already thinking ahead to the next pandemic. Future outbreaks may well be deadlier and more contagious than COVID-19. What good will our high-tech vaccines be if not enough people will take them?
Larson was born in 1957, and grew up in Boston. Her father was an Anglican priest, and her mother was a professor of German. The doors of home and church were unbolted and heavily trafficked, the church as likely to host Passover Seders as N.A.A.C.P. meetings. As a child, Larson spent hours in the basement darkroom with her father, who taught filmmaking and communications in addition to working as a priest; in the nineteen-sixties, those pursuits converged in the civil-rights movement, which he documented on film. The day after Martin Luther King, Jr., was assassinated, Larson’s father headed to Memphis with his camera. Larson, who was eleven at the time, remembers him warning her and her younger brother that he might end up in prison, but for a good cause. “I grew up understanding the power of belief,” she told me.
At Harvard, Larson started as a biomedical-engineering major, then switched to studying sociology and photography. For her senior thesis, she photographed children with Down syndrome who’d been mainstreamed into the public schools. After graduation, she spent a fellowship year in Israel, studying how Jewish and Arab children played together, then made a similar study among Muslim and Hindu children in India; later, as a graduate student in anthropology at the University of California, Berkeley, she worked with a Punjabi community in England that was predominantly Sikh, but changing under the influence of Muslim immigrants from Pakistan. Other researchers had warned her that it would be hard to gain the trust of people in such vulnerable communities; her solution, she recalled, was just to “be interested.”
One morning during her time at Berkeley, as she was driving down a coastal highway in the fog, her Volkswagen hatchback flipped over a cliff and into the Pacific Ocean. The car slammed roof first into the water, sinking until only its rear wheels broke the surface; Larson was trapped upside down in the car. Two elementary-school kids cutting through the redwoods on their way to school managed to contact rescuers, who pulled her from the car, unconscious, after forty-five minutes. Larson survived the crash with only a case of hypothermia and a ticket for driving with an out-of-state license. Her father had always stressed the importance of listening to those who are overlooked, and her rescue by children reinforced that lesson. “I’ve learned to pay close attention to people on their own terms,” she said.
In 1990, fresh out of grad school, Larson took a job at Apple Computer, studying how the presence of computers affected students and teachers in a series of Los Angeles classrooms. Later, she moved to Xerox PARC, where she observed office workers adjusting to new technologies, such as fax machines. Among other things, Xerox hoped to install a printer on every desk, but Larson found that workers preferred walking to the printing room. “It reminded me of women going to the well in Nepal,” she said—it was a detour with a social function. Xerox wanted to know how workers at an international company related to fax machines, and UNICEF, in New York, had recently splurged for two. Larson spent a year studying faxes in the organization, then took a job there and was sent to Fiji.
For six years, Larson worked to help South Pacific countries improve children’s welfare. Attending to people on their own terms turned out to be critical. Once, she obtained an audience with the King of Tonga, who preferred to hold forth about his slimming regimen. (He’d previously held the Guinness World Record for world’s heaviest monarch.) Larson talked with him about his cycling and his penchant for coconuts; the king eventually signed on to the United Nations Convention on the Rights of the Child.
It was impossible to ignore how H.I.V. was ripping through Asia. There was no vaccine or effective treatment. Although Larson had jettisoned pre-med as an undergrad, anthropology turned out to be the right specialty for the crisis. “The social, cultural, and human dimensions—that was all we had,” she said. She moved to Geneva to join the World Health Organization, focussing on the factors that shape behavior around infectious diseases. She crisscrossed the globe for the next two years, leading workshops, meeting government officials, collaborating with local health teams, and observing communities that were getting it right. Her mother, however, had died of ovarian cancer. Larson herself had contracted a host of illnesses—dengue fever, hepatitis E, amoebiasis, giardiasis, eosinophilic meningitis, and cerebral malaria—and wanted to move closer to her father. She returned to New York to work with UNICEF’s newly formed Gavi Alliance, in 2002.
The Nigerian vaccine boycott, which started two years into Larson’s tenure with Gavi, brought her face to face with an unsettling aspect of global health: even the most strenuously wrought achievements—ones that required years of painstaking logistical, financial, and diplomatic effort—could be gutted by the mere puff of rumor. The local strain of polio ultimately spread to twenty countries, as far afield as Yemen, Saudi Arabia, and Indonesia. Fifteen hundred children were paralyzed; it cost a half-billion dollars to contain the outbreak. The lesson, for Larson, was that global vaccination efforts would never succeed without a detailed understanding of rumor and a rigorous process for creating trust.
