Lyme Disease Is Spreading. Why Don’t We Have Drugs to Stop It?

Q: Every three months, I give my dog a beef-flavored chew that kills any ticks that bite her. She has also been vaccinated against Lyme disease. Why don’t these options exist for people?

“It’s funny, in Lyme disease, animals have so many more options than humans do,” said Dr. Linden Hu, a professor of immunology at Tufts University School of Medicine. That includes several Lyme vaccines, as well as oral and topical tick-prevention medications.

Safety concerns and doubts about public acceptance have hindered the development of these types of drugs for people. But with rates of Lyme and other tick-borne illnesses increasing in recent years, researchers are exploring new (and old) options, and a few are now being tested in human clinical trials.

Vaccines

Between 1999 and 2002, there actually was a human vaccine for Lyme disease available in the United States. The drug, called Lymerix, was approved by the Food and Drug Administration in 1998 after clinical trials deemed it safe and effective for preventing infection with Lyme-causing bacteria. It was recommended for people between the ages of 15 and 70 who were living or working in areas where Lyme disease was common.

Shortly after people started receiving the shots, reports of side effects emerged, most notably symptoms of arthritis. Federal health officials “looked at it very carefully” and didn’t find evidence that the vaccine was unsafe, said Dr. Erol Fikrig, an infectious disease expert at the Yale School of Medicine, who was involved with developing the drug.

But the reputational damage had been done. Sales of the Lyme vaccine plummeted, and in 2002, GlaxoSmithKline, which manufactured the drug, pulled it from the market.