Lyme disease: is a solution on the way?

As a former martial arts world champion, who trained daily and enjoyed camping and hiking at weekends, Stephen Bullough had always prided himself on leading a healthy life.

Like most people, he thought very little when he was bitten by a tick on a camping holiday close to home in Wigan in 2014, never suspecting that this tiny bite would unleash an infection in his body that would one day leave him permanently incapacitated.

“He had a rash on his right arm, which we put down to ringworm, so we put a bit of cream on it and thought nothing of it,” remembers Angela, Stephen’s wife. “In 2015, he started to develop these cognitive problems, getting words wrong. We laughed about it at first, joking, ‘You’re getting old now.’”

But a year later, Bullough began to experience sudden seizures and muscle weakness, leaving him with severe difficulties walking. Over the past three years, his condition has rapidly deteriorated, leaving him unable to see, permanently bed-bound and often suffering multiple seizures at a time.

“Last May, he had a massive seizure and then his whole body was convulsing,” says Angela. “That’s the day he went blind and has never walked or seen since. He then started having back-to-back seizures; he’s in hospital once a month because they just won’t stop, regardless of how many drugs they give him. One weekend, he had 40 seizures.”

Bullough was eventually diagnosed with Lyme disease, an illness caused by various species of bacteria in the genus Borrelia that live in the guts of ticks. Once transmitted to humans, it can attack the immune system and lead to serious health complications such as arthritis, meningitis, neurological problems, even heart failure. While Lyme disease can sometimes be treated with antibiotics if detected early, not everyone responds and for patients such as Bullough who have developed chronic symptoms, there is currently no cure.

This is particularly concerning as Lyme disease appears to be on the rise, something scientists have attributed to climate change, creating conditions in which tick populations can thrive. While the disease is currently estimated to affect between 2,000 and 3,000 new people every year in the UK, the National Institute for Health and Care Excellence (Nice) suspects the real figure is far higher.

But for scientists, one of the most tragic aspects of Bullough’s story, as with those of many other patients, is that it could potentially have been avoided. In the late 1990s, the first preventive human vaccine, called LYMErix, was developed and 1.4m doses had been administered by the end of 2001. The data suggests it was highly effective, protecting against the disease in almost 90% of cases.

LYMErix wasn’t perfect. It was relatively expensive, did not work in young children, only protected against one strain of Lyme disease and was only available in the US. But it appeared to be the first step towards eradicating the disease for good. Anti-vaccine fear saw it vanish from the market, however, and with that, all scientific research and investment in the field ceased.

The death knell for LYMErix proved to be a theory that the vaccine could induce autoimmune reactions in humans. This was partially based on a study from 2000 that found the vaccine contributed to arthritis in hamsters, as well as entirely hypothetical concerns from the US Food and Drug Administration (FDA) panel, which approved LYMErix, that the immune system might overreact and begin to attack healthy tissue along with the Borrelia bacteria.

These ideas were subsequently disproved, but the fear continued to spread. In 1998, the now retracted Lancet study linking the MMR vaccine to autism had been published and the modern anti-vaccine movement was gathering momentum.

Class action lawsuits were filed against LYMErix’s manufacturer after several incidents of arthritis were reported. But while the evidence suggested that these incidents were unconnected to the vaccine, sales began to plummet and in 2002, the product was withdrawn altogether.

“The consequences have been that, until recently, no manufacturer has wanted to touch this,” says Gregory Poland, who is head of the Mayo Clinic’s Vaccine Research Group in Minnesota. “Some of the anti-vax campaigners had published a statement saying that no matter what kind of Lyme vaccine they develop, we will organise mass protests and lawsuits. In the US, it takes about 10 to 15 years of research and about a billion dollars to develop a vaccine and get it licensed. Since LYMErix, nobody’s been willing to risk that.”

One of the great ironies of the LYMErix story is that while human vaccine development was subsequently quashed, the situation for dogs has never been better. Effective canine Lyme disease vaccines have long been available in both the US and the UK and there are reports of desperate individuals in high-risk areas persuading their vets to administer it to them. Poland is even hoping to conduct a study looking at whether this vaccine has conferred any protection.

“It’s a very odd scenario,” he says. “You have a safe and effective vaccine licensed by the FDA and anti-vax campaigners reject it. But on the other hand, you have people so desperate for protection that they’re even willing to take a canine vaccine that has never been studied in humans.”

But there are signs that the situation may be changing. The increasing prevalence of Lyme disease, combined with growing awareness about the threat posed by tick-borne diseases, has attracted new windfalls of government funding, particularly in the US.

In 2018, the National Institutes of Health spent $23m on Lyme disease research much of it earmarked for vaccine development, and with this, private companies are starting to return to the scene. The current leader is Vienna-based biotech Valneva, which is developing a vaccine that can protect against all six strains of Lyme disease in the northern hemisphere, and is currently preparing for a Phase II clinical trial. If everything goes according to plan, this vaccine could be licensed commercially in five years.

But the ghost of LYMErix is still hovering over vaccine developers. Valneva will end up testing its vaccine on more than 15,000 people before applying for licensing, to try and convince the public that it is safe. Despite this, it remains to be seen whether the product will prove commercially successful, as patient groups remain suspicious.

“The Lyme vaccine was not successful in the past and it is our belief that not enough is understood about the illness to produce a second vaccine,” says Lyme Disease UK cofounder Natasha Metcalf. “We do not know enough about the unique ways in which Lyme interacts with the immune system. People who have had Lyme do not gain immunity from the disease and we do not have enough research available on the best way to treat the illness. When so little is known, a vaccine seems premature.”

Because of such widespread patient scepticism regarding the idea of a Lyme disease vaccine, some researchers have proposed ways of protecting people from becoming infected that do not involve human vaccination. Scientists at the University of Tennessee are looking to develop a vaccine that can be encased in food pellets for mice and other rodents that carry ticks. The idea is that the pellets would be widely distributed in the environment in areas where Lyme disease is particularly prevalent and the vaccine would then kill the Lyme disease bacteria inside the ticks feeding on the animals.

Not all patients are against the idea of vaccines per se. Some would rather see the money being invested in vaccine development spent on devising treatments for those who are already gravely ill with the disease, and have been left with no other options.

Many of these patients feel neglected by the medical community due to the controversy that has long surrounded what is known as chronic Lyme disease. Despite numerous studies which have emerged showing that large numbers of patients suffer from chronic or Post-treatment Lyme disease syndrome (PTLDS), with symptoms persisting and worsening despite initial antibiotic treatment, sectors of the medical community both in both the US and the UK have refused to accept that the condition exists. A recent opinion piece in the New York Times, which claimed that PTLDS was not a problem, provoked widespread outrage.

“One big challenge has been that a considerable part of the medical community does not believe there is a problem,” says Kim Lewis, professor of molecular microbiology at Northeastern University in Boston, Massachusetts. “Chronic Lyme is kind of a dirty word. But studies from Johns Hopkins University estimate that 10-20% of Lyme patients suffer from that condition.”

Angela Bullough says that years of seeing specialist neurologists who refused to accept that her husband had Lyme, or would offer treatment options that ignored his worsening condition, left him suicidal. “My husband was at one point last year contemplating committing suicide and I know there are quite a few people with Lyme disease that do, because of the fact you’re simply left,” she says. “Nobody believes you.”

As a result, most funding for research into new treatments comes from private foundations rather than government bodies. But there are signs of hope on the horizon. Scientists believe that one of the reasons chronic Lyme disease exists is because conventional antibiotics are not powerful enough to kill all traces of Borrelia within the body and the remaining microbes – known as persister cells – repopulate and spread to other tissues.

“You need to be able to eradicate the organism in order to cure the infection and the disease,” says Monica E Embers, assistant professor of parasitology at Tulane University in New Orleans. “Borrelia spreads through the body, develops antibiotic tolerance, so you need drugs with good tissue penetration that can get through the blood brain barrier. But it’s a bit like cancer: if you don’t get every last cell, you could get a resurgence of the infection.”

Scientists are hopeful that they have identified a compound that could eventually prove to be the first treatment for PTLDS. Studies screening thousands of drugs to see which might prove to be lethal to Borrelia and safe for human tissue identified disulfiram, a drug typically used to treat alcoholism, as being particularly fit for purpose.

“You add disulfiram to a population of Borrelia growing in a test tube and it wipes out and essentially sterilises that population,” Lewis says. “And then if you add it to human cells or another bacterial species, it has no effect.”

At the moment, Columbia University Medical School in New York is recruiting patients for the first clinical trial of disulfiram for PTLDS. If it proves successful, Lewis hopes that having an effective treatment will go some way to ending much of the stigma surrounding PTLDS in the medical world.

“When doctors are faced with a problem they cannot solve, it is human nature to sweep it under the rug, to argue it away, to say that the problem does not exist,” says Lewis. “Because doctors have a simple choice, to tell the patient we have no treatment for your condition or to say you don’t have any condition. But I think doctors will be persuaded after there is clinical data showing that some intervention actually helps this condition.”

For patients such as Stephen Bullough, any signs of hope are everything. “If you don’t have hope, you’ve got nothing, so we certainly are hoping that some kind of new treatment protocol will be developed,” says Angela Bullough. “People will try anything, because you’re that desperate.”