The Current and Future State of Vaccines for Lyme Disease.

Lyme disease is caused by Borrelia species that are transmitted by Ixodes ticks prevalent in parts of the United States and Europe. A Lyme vaccine containing the outer surface protein A (OspA) antigens from the single Borrelia species most prevalent in the United States was marketed in the 1990s, but was withdrawn because of unproven concerns about safety, which led to insufficient sales. Since then, the incidence of Lyme disease has increased in the United States owing to the geographical spread of infected ticks. Lyme disease due to multiple different species of Borrelia is also widely prevalent in many European countries. New Lyme vaccines, using OspA antigens from multiple species of American and European Borrelia, are in advanced clinical development, and one such vaccine is in phase 3 trials. When licensed, new vaccines are likely to have an impact in preventing Lyme disease, although the need for periodic boosters remains to be defined.