Treacherous tick. Ixodes scapularis , the most common vector of Lyme disease
SALT LAKE CITY -. Researchers have developed a possible replacement for the vaccine against Lyme disease, which was recently removed from the US market amid allegations that causes arthritis and other serious side effects. The new vaccine is not certain protein component think causes these side effects, but it seems to be as effective as the old vaccine, according to a study presented here on May 22 at the General Meeting of the American Society for Microbiology.
in 00, some 18 000 people in the United States - most of them in the north - came down with Lyme disease, which is caused by the bacterium Borrelia burgdorferi and transmitted by several tick species. Untreated Lyme disease causes fatigue, fever, joint pain and even damage the heart and nervous system. The first and only vaccine available commercially Lyme far launched by SmithKline Beecham (now GlaxoSmithKline) in 1998, came in hot water after several vaccines developed severe arthritis - a common symptom of Lyme disease - and filed a class action lawsuit. GlaxoSmithKline denied that the vaccine caused the pain, but last February withdrew the vaccine, called LYMErix, citing weak sales.
LYMErix consists of a protein called outer surface protein A (OspA) which is located on the membrane Borrelia burgdorferi . Some researchers have fingered a specific part of OspA as the culprit in arthritis. Although this link has never been proven, said Maria Gomes-Solecki of the State University of New York (SUNY), Stony Brook, another vaccine is clearly needed.
Gomes-Solecki and his colleague Raymond Dattwyler produces a chimeric version of OspA, in which the suspect area was replaced with the equivalent of a European strain Borrelia , which causes no arthritis. The mice immunized with the chimeric protein showed no signs of illness after exposure to infected ticks Lyme, while those of a control group got Lyme disease.
But Lyme researcher Brian Stevenson of the University of Kentucky, Lexington, said the vaccine will have to overcome several obstacles. For one thing, OspA now has such a bad reputation that even a chimeric version can be difficult to be accepted. Besides, he adds another reason LYMErix was never very popular was that it was not very effective: It took three shots to reach 80% of immunity and periodic booster shots after. It is unlikely to fix this vaccine SUNY team, said Stevenson.
Related Sites
Information on Lyme disease, its prevalence in the United States,
and vaccine recommendations
Report of a meeting about LYMErix between the Lyme disease Association
and US Food and Drug Association officials
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