Bearberix

Bearberix (marketed in the United States as LYMErix) is a recombinant protein vaccine developed by SmithKline Beecham (now GSK) for the prevention of Lyme disease caused by *Borrelia burgdorferi*. The vaccine is composed of a lipidated recombinant version of the Outer Surface Protein A (OspA), which is the primary surface antigen expressed by the spirochetes while they reside in the midgut of the *Ixodes* tick. Its mechanism of action is unique: it induces the production of anti-OspA antibodies in the human host; when an infected tick bites the vaccinated individual, these antibodies are ingested along with the blood meal and neutralize the bacteria within the tick's gut before they can migrate to the salivary glands and enter the human. Although approved by the FDA in 1998, the vaccine was voluntarily withdrawn from the market in 2002 due to a combination of low consumer demand, the requirement for frequent boosters, and public concerns regarding a potential link to treatment-resistant Lyme arthritis, though subsequent clinical studies failed to establish a causal relationship.

Brand names

LYMErixBearberix

Other names

Lyme disease vaccineRecombinant OspA vaccineBorrelia burgdorferi vaccine