United States of America. The Food and Drug Administration has approved the first vaccine to aid in the prevention of Lyme disease, which is transmitted to people through the bites of ticks infected with Borrelia burgdorferi. The new vaccine (Lymerix: SmithKline Beecham) is approved for use in people aged between 15 to 70 years who live or work in grassy wooded areas where the infected ticks are present.

Although Lymerix may provide protection for a majority of people, it does not prevent all cases of Lyme disease. Therefore, people should continue to take standard preventive measures against infection, including wearing protective clothing, using tick repellent and removing attached ticks.

Lymerix contains a genetically engineered protein from an outer surface protein of B.burgdorferi, the spiral shaped bacterium that is responsible for Lyme disease. The surface protein stimulates antibodies that appear to disable the bacterium’s ability to infect the individual.

Lyme disease, which is rarely fatal, typically causes a characteristic “bull’s eye” rash and flu-like symptoms in the early stages of infection and occasionally facial weakness and heart problems. In the later stages of the disease, months or years later, some patients may have chronic arthritis or neurologic problems.

The vaccine appeared to be more effective when vaccine doses were given between January and April, shortly before the peak tick season in the northeast United States. It is not currently known how long protection against Lyme disease lasts after vaccination, although in trials the protection rate was 78% in the second year after three doses.

Reference: HHS News P98-39, dated 21 December 1998.