In the mid-1970s, physicians were puzzled after a cluster of children and adults in the town of Lyme, Connecticut, all developed mysterious, arthritis-like symptoms. They complained of recurrent bouts of pain and swelling in their joints; some developed fevers and rashes, others had unusual skin lesions. While doctors initially suspected that a virus might be the cause of the ailments, when a group of Yale scientists started to look closer, they discovered that the symptoms were caused by a bacteria transmitted by tick bites. The illness is now known as Lyme disease.

At first, most people didn’t see the disease as cause for widespread concern. After all, it only affected a few people, most of whom were presumed to be affluent Americans: the types who vacationed in Martha’s Vineyard or rode horses in the woods during their free time. But one scientist, named Sam Telford, was watching closely. The son of a World Health Organization parasitologist, Telford had grown up learning about all sorts of diseases that animals can spread and wanted to focus his career on preventing them. His colleagues at Harvard questioned why he was dedicating so much time to a medical problem that seemed insignificant, but as he continued his research, cases of Lyme began to rise, appearing in the grassy areas of Nantucket and around other parts of New England.

Telford’s persistence paid off. His research caught the attention of drug maker SmithKline Beecham, now GlaxoSmithKline, which asked him to work on a Lyme vaccine in response to the growing number of cases. In 1998, the US Food and Drug Administration approved the first-ever vaccine for Lyme disease, and within a year, as the disease spread to other regions of the US and into Canada, 1.5 million doses of LYMErix had been sold.

To Telford and others in the science community, the vaccine was a huge success. But the impact was short lived. Just one year after it hit the market, lawsuits started pouring in from patients who claimed the shot caused them harm. There was the New Jersey nurse who, after getting her second LYMErix vaccine in the late ’90s, complained of unbearable pain that escalated to a point where, she said, she could barely move when she woke in the morning; the mother who claimed that her daughter developed arthritis and lost peripheral vision in her left eye after the jab. In 2001, she told the Washington Post that getting her the shot was the “biggest mistake” of her life. One Philadelphia lawyer, who represented more than 350 plaintiffs, told the Guardian back in 2002, “We have people who got shots of this thing, and within days, they were in wheelchairs for the rest of their lives.” Even doctors at the time offered caution: in one New York Times article, an infectious-disease doctor and Lyme specialist said she’d recommend holding off on getting the vaccine for another year, until more questions were answered.

While the FDA found no evidence that the vaccine caused the adverse events that the claimants alleged—in fact, it was shown to be safe and about 75 percent effective in reducing the risk of infection during clinical trials—the damage was done. LYMErix’s public image was tarnished, and in 2002, after declining sales and waning public interest, GlaxoSmithKline pulled the vaccine off the shelves for good.

In the years since, no Lyme disease vaccine has been approved for human use, but that could change soon. In August, a new shot made by Pfizer and Valneva, called VLA15, entered the final stages of clinical trials. If it succeeds, it will be available to consumers in 2025. But, with the failure of LYMErix looming in the background, it’s become clear that companies, doctors, and governments have to adopt entirely new ways of communicating with the public if they want people to take it. These days, vaccine efficacy is just as much about language as it is about science.

“There have always been threads of trust and mistrust, particularly in health care. . . . But at the present moment, because of the ubiquity of social media and the diversification of where people get information, there is a much more manufactured effort to create that mistrust,” said Elvin H. Geng, an infectious-disease specialist, on an episode of Washington University’s Show Me the Science podcast. Better communication around vaccines, he adds, “may be one potential remedy for the afflicted social fabric of our times.”

In the years since Lyme was first discovered in Connecticut, it has spread to every one of Canada’s provinces. The disease is transmitted through ticks that carry a corkscrew-shaped bacteria called Borrelia burgdorferi. When an infected tick latches onto a human and bites—injecting a tiny bit of anesthetic with its small, hooked teeth so that its host doesn’t notice—it starts to pass bacteria into the bloodstream. Over time, that bacteria can cause multisystem, multistage inflammation in the body.

The disease can be cured with antibiotics, and stage-one symptoms like rash, headache, and chills will go away without causing long-lasting issues. But some patients—between 5 and 30 per cent—develop a condition called Post-Treatment Lyme Disease Syndrome (PTLDS), where symptoms like brain fog, arthritis, musculoskeletal pain, and even heart problems can become chronic—similar to what we’re starting to see with long COVID. A 2017 study out of Johns Hopkins University found that patients with PTLDS had poorer overall health and a lower quality of life than healthy subjects. But, because the symptoms of later-stage Lyme often overlap with other illnesses, it’s not uncommon for patients to struggle to get the correct treatment. As cases climb—and even more go undiagnosed—the burden falls not only on the patient but the health care system as a whole.

Today, Lyme is not only the most common tick-borne illness in both the US and Canada but also the fastest growing infectious disease in the US, according to the Centers for Disease Control and Prevention (CDC). One estimate by the Public Health Agency of Canada is that there could be as many as 10,000 new cases each year in the 2020s—almost three times the figure seen in 2021 (though the real number is likely much higher).

Lynora Saxinger, an infectious-disease specialist and professor of medicine at the University of Alberta, says the situation is poised to get worse. Ticks love humidity, and warmer temperatures caused by climate change are forcing them to head north. A 2017 government report found that, if current climate trends continue, Lyme-carrying blacklegged ticks will keep spreading, which makes the need for a solution all the more urgent. So why has it taken scientists so long to develop a new vaccine—especially when the technology already exists?

When LYMErix first hit the market, it was a novel development. The vaccine—administered in three doses and recommended for people ages fifteen to seventy—used the Borrelia burgdorferi surface protein to stimulate an immune response and create antibodies in a person’s bloodstream. Unlike traditional vaccines, which trigger a response after a host has already been infected, LYMErix attacked the disease directly in ticks. The acquired antibodies were essentially a Lyme elixir that could kill the bacteria in a tick’s gut before it could be transmitted.

Given the positive data that emerged from clinical trials, which included more than 10,000 people, coupled with the growing concerns of Lyme disease in endemic areas, like Connecticut and Massachusetts, drug makers and epidemiologists didn’t anticipate much controversy around the vaccine, says Robert Aronowitz, a professor of social sciences at the University of Pennsylvania who authored a paper on the fall of the Lyme vaccine. But, once LYMErix got FDA approval, the CDC’s Advisory Committee on Immunization Practices (ACIP), which recommends vaccines for clinical use, gave it a lukewarm review: a “should consider” recommendation for people at high risk and a “may be considered” recommendation for those exposed to areas where ticks live. As Aronowitz wrote in his paper, some scientists considered the shot to be a “yuppie vaccine” that was manufacturer and consumer driven. At the time, the assumption was that it was primarily of interest to anxious suburbanites who “will pay a lot of money for their Nikes and their Esprit and shop at L.L. Bean,” wrote Aronowitz. It wasn’t that the ACIP was questioning the science; they just didn’t see any urgent need for the vaccine.

“That kind of recommendation matters in terms of whether a vaccine could be reimbursable by an insurance company,” says Telford, now a professor at Tufts University’s Cummings School of Veterinary Medicine. In the US, where the shot was being developed, that reception mattered even more. “This vaccine was not reimbursable by insurance; it was an elected vaccine.”

Telford says that the weak recommendations led to concerns around limited interest—something researchers had already been grappling with, since Lyme is a treatable disease and was, therefore, viewed as less serious. This created a self-fulfilling prophecy for SmithKline Beecham, which, with its misdirected marketing efforts, alienated many of those who were interested in the vaccine. Instead of trying to sell the vaccine to health care providers, the pharmaceutical company advertised directly to consumers, like gardeners, golfers, and even people who barbeque outdoors. It seemed like their strategy was to try to make people more worried about being exposed to Lyme. One TV ad at the time included the line “I never thought I was a target for Lyme disease . . . until I found out you can get it in your local park, in your own backyard, or even mowing the lawn.”

Around the same time, anti-Lyme vaccine sentiment was bolstered by citizen-advocacy groups concerned with raising Lyme “awareness.” While there was initial interest in the vaccine, some members claimed that, in clinical trials, scientists used narrow, objective criteria for what constitutes a Lyme disease diagnosis by including symptoms like rashes, headaches, neck stiffness, and neurological problems. For those who believed chronic Lyme symptoms were often misunderstood or ignored, this meant that many suffering patients were now essentially being told that they needed to meet specific criteria to be diagnosed, which might prevent them from getting the treatment they needed. In response, these groups began to lobby decision makers like the National Institutes of Health. Their aim was to influence not only how much money should be devoted to their cause but also to sway what exactly researchers should be studying. Tension was brewing between scientists and Lyme advocates. In a 1997 op-ed for the New York Times, scientist Alan Barbour wrote, “Basing their arguments on anecdotes and unsubstantiated information, they want to be coaches as well as boosters. Yet they are not qualified to call the plays. . . . Is this really how we want science to be conducted? Those who suffer from Lyme disease are better served by letting scientists do their jobs.”

Bad press continued to plague the vaccine after a string of lawsuits were filed against the LYMErix maker in the early 2000s that alleged the vaccine did not mention the possibility of developing arthritis. Early studies showed that when the surface protein—the same one used in the vaccine—was injected into the joints of hamsters, they could develop arthritis. In humans, however, this was never proven to be a real threat. Lawyers argued that, regardless of what the science showed, people should have still been warned of the theoretical risks. In other words, the suits had little to do with any real adverse reactions but, instead, with the wording around them. “In the hearings, a lot of people claimed that they got something like Lyme disease from the vaccine, and even though clinical trials did not show much in the way of unusual, rare reactions, individuals’ claims in the hearings coalesced with an antipathy to the vaccine,” Aronowitz explains. Research has shown that the rare stories about someone suffering an adverse reaction are more “sticky” than real-world data. In other words, one bad headline can often be enough to convince people that a vaccine is too dangerous, even if there’s overwhelming research showing otherwise—which is exactly what happened with LYMErix.

With its reputation in a shambles, the vaccine’s sales dropped to around 10,000 doses in 2002 from 1.5 million in 1999. Connaught Laboratories, which was working on developing another Lyme disease vaccine at that time, saw what happened with LYMErix and voluntarily withdrew its project. Trying to convince people that it was safe, they decided, would be too difficult. That sentiment persisted through the following years, and no vaccine ever hit the market.

North America’s rejection of the Lyme disease vaccine is hardly unique. As early as the end of the eighteenth century, after the smallpox pandemic killed millions of people, scientists were met with skepticism after creating one of the first-ever vaccines to fight the disease. While times were different and the technology was new, the reasons for the pushback overlap with the same arguments vaccine skeptics make today: a refusal due to religious beliefs, anger over vaccine mandates (the UK mandated smallpox shots for all children in 1853), and a general distrust of medical authorities.

Public perception of vaccines went on to create a slate of problems for the DTP—diphtheria, pertussis (whooping cough), and tetanus—vaccine in the 1970s and ’80s. After a 1974 report from a UK hospital alleged that children who had been vaccinated against DTP suffered neurological conditions, such as convulsions and muscle weakness, people began to doubt whether the vaccine was really safe. TV reports highlighting the controversy emerged alongside noisy parent anti-vax groups, leading to confusion over the vaccine’s benefits. Despite the fact that the risk of the disease was far more dangerous than the shot itself, the media made many parents believe that it was too risky, and they refused to get their kids immunized. Vaccine uptake slowed, and soon after, there were “near-epidemic outbreaks” of whooping cough in several parts of the US and Europe.

Even as early as 2019, months before the first cases of COVID-19 emerged, the WHO listed vaccine hesitancy among the top ten threats to global health—a concern that was only amplified by the pandemic. Vaccines have protected millions of people from severe disease, hospitalization, and death, but mis- and disinformation around their side effects—including things that have been debunked, like mRNA technology having the ability to alter DNA—slowed uptake. “[Anti-vaxers] can be very vocal and very compelling and can influence a lot of people,” says the University of Alberta’s Saxinger.

While the spread of dis- and misinformation has played a major role in shaping the narrative, some researchers say that it’s actually a lack of information that’s causing problems. That’s where the LYMErix vaccine failed; that’s where COVID vaccines failed; and it’s where future vaccines will fail unless health care institutions start communicating more effectively with the public.

After a 2022 independent review of the CDC found that ambitious reforms were needed in order to adapt to the current moment, director Rochelle Walensky told PBS News Hour that, “prior to this pandemic, CDC was talking to scientific experts. They were talking to public health experts. . . . [But] it has become very clear that we’re now talking to the people. We need to distill the science that we’re learning to people so it’s actionable, and it’s implementable, it’s understandable and accessible.”

That same sentiment applies across the health care spectrum. In a 2015 paper on health communication and vaccine hesitancy, published in the journal Vaccine, researchers recommended that a communication strategy be integrated into the planning of an immunization program from its inception. “Lack of communication at the outset can lead to serious problems with implementation of the programme, and leaves open the space for communication by people and organizations with vested anti-vaccine interests,” they wrote. Now, with a slew of new Lyme vaccines in the works, drug companies need to be mindful of that crucial last step of the process: vaccine development starts with the science but ends with the pitch.

Last November, scientists at Yale University published results from their mRNA vaccine that showed protection against Lyme disease in guinea pigs. The vaccine, which uses the same technology as COVID shots, causes a “quick response” in the skin to the tick’s saliva, limiting the amount of time that the tick has to feed on the blood of the host and reducing the chances of infection. Over at the University of Massachusetts medical school’s MassBiologics, a nonprofit, FDA-licensed vaccine maker, researchers are working on a preventative shot called Lyme PrEP. And Pfizer, riding high on its COVID-vaccine success, and Valneva SE, a French biotechnology company, might actually see their product on the market soon. Their vaccine, which completed phase-two clinical trials in April 2022, uses the same technology as the original LYMErix. With phase three now underway, Pfizer says it has plans to enrol approximately 6,000 participants over five years and at fifty sites—including Finland, Germany, Sweden, and the US—where Lyme disease is highly endemic.

Speaking to the Associated Press, Annaliesa Anderson, Pfizer’s vaccine chief, said that when the last vaccine was pulled from the market, “there wasn’t such a recognition, I think, of the severity of Lyme disease.” The drug maker has consistently said in statements about its vaccine that the increase in the global rates of Lyme disease means it’s crucial that people have an option to protect themselves. Trial participants also seem to be keen. One woman who received the shot on Martha’s Vineyard told a local paper she was “thrilled” to be vaccinated. Such responses may not yet be commonplace, but there’s hope that they might reflect a larger shift in consumer demand.

“At a moment when pessimism is the zeitgeist, I think that optimism in an optimistic story helps us regain some energy, some brightness, some minor moment of, sort of, inspiration,” Geng said of the future of vaccines on Show Me the Science. “And I think that helps us . . . feel a little bit better and see a little bit of a way forward.”

Laura Hensley
Laura Hensley (@LolaHensley) is a Toronto-based lifestyle journalist. Her work has appeared on Global News and MTV and in Refinery29, Flare, Toronto Life, Chatelaine, the National Post, and Fashion.
Leah Kwak
Leah Kwak ( is a Korean Canadian illustrator from the GTA, working for clients such as the University of Toronto and the City of Mississauga.