Vaccination of guinea-pigs against tuberculosis with B.C.G / C.C. Okell and H.J. Parish.

  • Okell, C. C. (Charles Cyril), 1888-1939.
Date:
[1928?]
Catalogue details

Licence: In copyright

Credit: Vaccination of guinea-pigs against tuberculosis with B.C.G / C.C. Okell and H.J. Parish. Source: Wellcome Collection.

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    VACCINATION OF GUINEA-PIGS AGAINST TUBERCULOSIS WITH B.C.G. C. C. OKELL AND H. J. PARISH. From the Wellcome Physiological Research Laboratories, Beckenham, Kent. Received for publication January 16th, 1928. This communication deals with four experiments which have been carried out during the last three years in an endeavour to repeat Prof. Calmette’s work on the prophylaxis of tuberculosis in guinea-pigs with vaccine B.C.G. In each experiment a group of animals received one or more injections of the vaccine subcutaneously or intravenously ; after intervals of from 5 to 12 weeks to allow for the development of immunity, the vaccinated guinea-pigs and an approximately equal number of controls of similar weights were given an infecting dose of virulent B. tuberculosis. All the animals were observed regularly and weighed at weekly or fortnightly intervals. Post-mortem examinations were performed on all dead guinea-pigs. Those animals which died from intercurrent diseases too early in the experi¬ ment to develop tubercular lesions visible at autopsy as a result of the infecting dose were excluded from the comparison of the protected and unprotected groups. Experiment 1.—This experiment is to be regarded as a preliminary one only (Chart 1). Five guinea-pigs, which had received 20 mgm. of B.C.G. subcutaneously 12 weeks previously, were given an infecting dose of virulent organisms (human strain) contained in a suspension of triturated gland from a tubercular guinea-pig. Six guinea-pigs were injected with gland only as controls, and were all dead from generalized tuberculosis at the end of 16th week, the average period of survival being 11 weeks. When the last of the control guinea-pigs died, all the vaccinated guinea-pigs, apparently fit and well-nourished, were killed; at autopsy they all showed evidence of generalized tuberculosis, though the lesions they exhibited wTere less advanced than in the control animals which had died at an earlier date as a result of their infection. In later experiments great care was taken to select guinea-pigs of exactly comparable weight and physical condition for the two groups, but in the preliminary experiment the vaccinated animals were in rather better condition and slightly heavier than the controls at the time of infection with virulent organisms. Even when this was taken into consideration the results were of such promise that further experiments were arranged. Experi?nent 2.—In this experiment the vaccinated guinea-pigs were given the same dose of B.C.G. (20 mgm.) as in the previous experiment, but the infecting dose was 0'5 mgm. of the virulent human strain we use for the routine infection of guinea-pigs for the standardization of tuberculin. The interval between the injection of the living vaccine and the injection of 1