In 1998, the LYMErix vaccine was rolled out by SmithKline Beecham (now GlaxoSmithKline). It was a three-part vaccine that was found to be about 76% effective against Borrelia burgdorferi, a corkscrew-shaped spirochete bacterium that causes Lyme disease. It was intended for people 15 to 70 years old living or working in areas with high rates of Lyme disease.
The LYMErix vaccine caused the immune system to generate antibodies against B. burgdorferi—specifically, against a protein on the outer surface of the bacteria called outer surface protein A (OspA). These Lyme-killing antibodies worked in a unique way: When a tick bit a vaccinated person, it ingested the person’s blood and antibodies, which traveled into the tick’s gut, where the antibodies destroyed the bacteria before it ever entered the human body.
So what was the problem? Soon after the vaccine was introduced, reports began trickling in about pretty intense side effects, including arthritis, neurologic symptoms, and cognitive issues. And in 1999, a class action lawsuit was filed against SmithKline Beecham (SKB) by 121 people who had received the vaccine. They claimed that SKB knew and failed to adequately warn doctors and patients that certain people may be genetically predisposed to developing autoimmune arthritis in response to the vaccine, and they wanted SKB to update the vaccine’s safety warnings to mention arthritis.
Lyme disease itself can cause arthritis, so the claims about LYMErix raised a lot of questions. While the vaccine did not contain live bacteria, and thus couldn’t cause Lyme disease, people began to worry about its approach to generating antibodies against OspA. Why? Around this same time, scientists discovered that people with a certain genetic variant (HLA type DR4+) were more likely to develop arthritis after getting Lyme disease. They were also more likely to generate autoantibodies (antibodies that mistakenly target your own cells) in response to OspA. Because of this Lyme-OspA-autoimmunity connection, experts considered the possibility that LYMErix might also cause arthritis in patients with the DR4+ variant.
But in 2001, an FDA advisory panel concluded that there wasn’t sufficient evidence to support claims that LYMErix caused adverse events, including arthritis. By that time, 1.4 million doses of the vaccine had been distributed and the Vaccine Adverse Events Reporting System (VAERS) database included only 59 reports of arthritis associated with the vaccine—a number that experts said was in line with the rates of arthritis in unvaccinated individuals. Even so, SKB pulled the vaccine from the market in 2002, citing low demand resulting from all of the unfavorable media coverage caused by the lawsuits.
To this day, the safety of LYMErix is debated. According to some, the downfall of LYMErix represents the loss of a powerful tool for Lyme disease prevention. But other medical experts aren’t so sure the vaccine was completely without fault or risk, especially since more definitive long-term safety studies were halted when the vaccine was pulled off the market. In his new book Chronic: The Hidden Cause of the Autoimmune Pandemic and How to Get Healthy Again, Steven Phillips, M.D., says he continues to hear from patients who say they still haven’t recovered from their LYMErix injuries nearly 20 years later. (Clearly, Lyme disease is a complicated matter.)