B C G

1. SYNOPSIS OF HISTORY I HAVE been asked to speak to you this evening on the subject of B C G vaccination against tuberculosis. For the benefit of those of you who are not familiar with the story, I thought I would give a brief outline of the history of the development of the vaccine. 'T'he vaccine is named after Calmette and Gu-erin, the two pioneer workers in this field of medical research. In 1908 Calmnette started to grow this particular strain of bovine tubercle bacillus oin special culture media. 'T'he research continued for many years, using different experimental animals to determine first, the harmlessness of the vaccine and second, to test its immunizing powers. Finally, in 1923, the plunge was taken and the vaccine was given by Weill Halle to newborn infants in Paris. At this period it was given by mouth dissolved in milk. 'I'hese years of experiment were required in order to produce a vaccine that is stable in virulenice and potency, one that is incapable of producing a progressive tuberculous disease and at the same time has the power of conjuring up the protective mechanisms of the body, so that a possible future virulent infection will be successfully resisted. The vaccine used in every country is grown from the original strain of Calmette bacillus obtained from the Pasteur Institute in Paris, but the subsequent methods of culture vary in different countries as do the technique of vaccination and the dosage prescribed. In France the organism, originally cultured on bile potato, is now grown on Sauton potato in Roux tubes, and it is administered in the main by the scarification method. In Russia the vaccine is still largly given by the oral route, while in Norway, the multiple puncture method of administration is favoured by some workers. The administration of the vaccine commenced in Scandinavia in 1925 and about a year later Heimbech of Norway was the first to try giving the vaccine by subcutaneous injection, but this method was soon abandoned, as it gave too high a proportion of local abscesses. In 1928, Dr. Wallgren of Sweden introduced the intradermal techniique for B C G innoculation, which is now the standard method used in the Scandinavian countries and the one which has been adopted here in Northern Ireland.