Vaccines: Safety in Numbers

Right from the start of the first field tests, doctors and parents alike were troubled by the new measles vaccines. A single dose of the attenuated (weakened but live) virus vaccine produced nearly 100% immunity to the disease and its possibly serious aftereffects, but it also caused fevers and rashes all too similar to symptoms of the natural disease. The killed virus vaccine was almost reactionfree, but it might not provide as long-lasting immunity as the live virus. Even with a double inoculation-a shot of live virus in one arm, a shot of gamma globulin containing measles antibody in the other-every fifth child still ran a disturbing fever.

After a two-year study among 601 children, Dr. Samuel Karelitz and a medical team at Long Island Jewish Hospital have reported in the A.M.A. Journal on "simple, safe and effective" alternatives using both vaccines. The doctors found that the killed virus provides 100% immunity if given in three monthly doses. It can also be used to stimulate the formation of protective antibody before a child gets a shot of the more potent live virus. In either case, side effects are slight and infrequent. The investigators gave the live virus vaccine to 296 children who had already had one dose of the killed virus, and only 15% of the subjects developed a fever; 3% got a mild rash. For those who had two doses of killed virus before getting live virus shots, reactions were reduced by half. Of 75 given three killed virus shots, only one ran a fever and one developed a rash after an injection of the live virus vaccine.