IN 1908, after 15 yr. of careful research, Calmette and Guérin produced a completely attenuated suspension of living tubercle bacilli, which was named BCG.1 This suspension, when injected as a vaccine, produced a relative immunity which would give a certain degree of resistance to virulent tubercle bacilli. However, if an acquired resistance to virulent tubercle bacilli could be combined with a BCG vaccination, the immunity following the BCG vaccination could be converted into a more fixed immunity.2
The original BCG vaccine was so attenuated that it could not in itself cause progressive disease in experimental animals.3 The cultures have been handed down from the original production, and, so far as is known, all the strains of the vaccine now in use have been derived from the attenuated culture produced by Calmette and Guérin.
Gradually, over the years, the value of BCG as a preventive of tuberculosis became
LINHART WO. INDUCED OCULAR TUBERCULOSISReport of a Probable Case. AMA Arch Ophthalmol. 1951;46(3):271-276. doi:10.1001/archopht.1951.01700020278004