Vaccination for TB

Among the many mysteries of tuberculosis, none is greater than the inability of doctors on opposite sides of the Atlantic to agree on the value of BCG vaccine (TIME, Dec. 25, 1950) as a TB preventive. Medical men in Europe, and especially Scandinavia, look at the reports on their BCG programs and see "proof" that the vaccine is effective in conferring immunity. Doctors in the U.S. look at the same reports (supposedly scientific, and therefore objective) and sneer: it's no good. In this crossfire the British stayed neutral for years, finally started a searching BCG test of their own. Their conclusion, after five years of a continuing study: BCG is at least effective in preventing TB among teenagers (the most susceptible group) in industrial England.

The British test was as elaborate as the famed U.S. Salk vaccine trials in 1954, though not as extensive. In London, Birmingham and Manchester 56,700 high school children of 14 to 15 1/2 took part: 13,300, who reacted negative to the tuberculin test, were left unvaccinated as controls; 14,100 more received BCG vaccine; 6,700 got another type of vaccine, vole bacillus.* Another 22,600 children, all of whom showed positive in tuberculin tests, were left unvaccinated as a second group of controls for comparison.

For 2 1/2 years all participants in the test were checked with examinations and X rays. There were no deaths from TB, but 165 cases cropped up. Of these. 64 were in the negative-unvaccinated group, for an annual rate of 1.94 cases per 1,000; 13 were in the BCG group, a rate of .37 per 1,000, and seven were in the vole bacillus group, for a rate of .44. Of particular importance: not one of the TB cases in the vaccinated groups was of the especially dangerous meningeal (brain covering) or miliary (throughout the body) variety. There were 81 cases among children with positive tuberculin reactions -- a significantly higher rate than among the vaccinated. Said London's Lancet: "The results are unequivocal."

* Made from an organism found in voles (British field mice). This bacillus (Mycobacterium muris) is a close kin to the human-type tubercle bacillus, but does not cause disease in man. The question before this test was whether it could confer immunity against TB (as cowpox does against smallpox).

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