A VACCINE CONSISTING OF RECOMBINANT BORRELIA-BURGDORFERI OUTER-SURFACE PROTEIN-A TO PREVENT LYME-DISEASE

Background Lyme disease is a multisystem inflammatory disease caused b y infection with the tick-borne spirochete Borrelia burgdorferi and is the most common vector-borne infection in the United States. We asses sed the efficacy of a recombinant vaccine consisting of outer-surface protein A (OspA) without adjuvant in subjects at risk for Lyme disease . Methods For this double-blind trial, 10,305 subjects 18 years of age or older were recruited at 14 sites in areas of the United States whe re Lyme disease was endemic; the subjects were randomly assigned to re ceive either placebo (5149 subjects) or 30 mu g of OspA vaccine (5156 subjects). The first two injections were administered 1 month apart, a nd 7515 subjects also received a booster dose at 12 months. The subjec ts were observed for two seasons during which the risk of transmission of Lyme disease was high. The primary end point was the number of new clinically and serologically confirmed cases of Lyme disease. Results The efficacy of the vaccine was 68 percent in the first year of the s tudy in the entire population and 92 percent in the second year among the 3745 subjects who received the third injection. The vaccine was we ll tolerated. There was a higher incidence of mild, self-limited local and systemic reactions in the vaccine group, but only during the seve n days after vaccination. There was no significant increase in the fre quency of arthritis or neurologic events in vaccine recipients. Conclu sions In this study, OspA vaccine was safe and effective in the preven tion of Lyme disease. (N Engl J Med 1998;339:216-22.) (C) 1998, Massac husetts Medical Society.