Federal health authorities are investigating whether some people who received the vaccine against Lyme disease later developed severe cases of arthritis and even Lyme disease itself as a result.

The Food and Drug Administration has received reports of such problems, mainly from doctors and researchers in the Northeast. The vaccine, made by SmithKline Beecham Biologicals, a subsidiary of the British pharmaceutical giant SmithKline Beecham, was approved by the drug agency two years ago, and about 440,000 Americans have received it. SmithKline Beecham defends it as safe.

Dr. Susan S. Ellenberg, director of biostatistics and epidemiology at the F.D.A., said the agency, working with the Centers for Disease Control and Prevention, would investigate the reports ''to find out what the cases really are, to get more information.'' Dr. Ellenberg and Dr. Walter A. Orenstein, assistant surgeon general and director of the centers' national immunization program, said it remained to be determined whether the vaccine was the cause of the reported illnesses.

Article Here- http://www.nytimes.com/2000/11/21/science/concerns-grow-over-reactions-to-lyme-shots.html?pagewanted=all&src=pm