We’ve all heard the advice about avoiding Lyme disease. If you walk through wooded or grassy areas where it’s prevalent, you should use insect repellent. Cover exposed skin. Check yourself thoroughly once you return home, and take a shower. If you see a tick, pluck it off your skin with tweezers. Look out for a bull’s eye-shaped rash and flulike symptoms in the summer.
About 30,000 cases of Lyme disease are reported to the Centers for Disease Control and Prevention each year, making it the most commonly reported vector-borne illness in the United States. That number has tripled over the last 20 years. And experts estimate that the actual number of cases — not just those that happen to be reported to the agency — is more like 300,000 per year.
If Lyme has become so common, why isn’t there a vaccine for it? Well, here’s something you may not know: There used to be one, but it was taken off the market more than 15 years ago. And there’s only one new vaccine candidate in the pipeline.
“Clearly, the problem is getting worse,” said Dr. Paul Mead, a top scientist at the C.D.C. “For years, we have been advocating that people use repellents, do tick checks, spray their yards. That remains good to do, but it’s not enough.”
Here are the basics
Lyme disease was first recognized in the mid-1970s, after a cluster of adults and children in Lyme, Conn., started experiencing symptoms of arthritis. Additional symptoms may include fever, headache, fatigue and rash.
The disease is mainly found in Northeastern and North-central states and Northern California, though a recent report found it had spread to all 50 states. It’s also found in parts of Canada, Europe and northern Asia.
Lyme disease is usually handled with a short course of antibiotics. But without treatment, infections can spread to the heart and nervous system and cause serious problems. Additionally, some patients experience symptoms even after taking antibiotics, what the C.D.C. refers to as “post-treatment Lyme disease syndrome.”
“Chronic Lyme” is also a term you may have heard. It is sometimes used to describe persistent symptoms of infection, even in people who have not received a diagnosis of Lyme. The C.D.C. and many other experts don’t support the use of the term because of that confusion.
‘A public health fiasco’
A vaccine for Lyme disease, called LYMErix, was released by SmithKline Beecham — now GlaxoSmithKline — in 1998. It was found to be 76 percent effective in adults after three doses.
But the company took it off the market less than four years later, citing low sales, amid lawsuits from patients who said the vaccine caused severe arthritis and other symptoms. Some claimed that the vaccine had provoked an autoimmune reaction.
Studies never showed a direct link between LYMErix and any chronic side effect or serious complication. But patients’ claims about it, and resulting media coverage, were sufficient to make doctors and patients wary.
Dr. Gregory Poland, a vaccinologist at the Mayo Clinic, has written that public concern, induced by anti-vaccine groups and class action lawsuits, resulted in LYMErix being withdrawn from the market.
“There’s a big difference between what’s claimed and what’s proven,” he said.
The high cost of the vaccine and confusion over who should get it and how many doses were needed didn’t help its prospects. Additionally, a vaccine was never intended to replace “personal protective measures” like tick checks. After all, ticks can carry a number of diseases besides Lyme.
Dr. Stanley A. Plotkin, an emeritus professor of pediatrics at the University of Pennsylvania, said that the loss of the vaccine was a “public health fiasco.” He and other researchers said that in the years since, public opposition prevented drug companies from investing in another vaccine that could fail on the market.
“It’s a situation that has never existed before,” he said. “You have a vaccine that works, you know it works, you know the disease is prevalent, but there’s no vaccine on the market, except for dogs.”