Trial of BCG Vaccines in South India for Tuberculosis Prevention

Tuberculosis Prevention Trial, Madras (1980) Trial of BCG Vaccines in South India for Tuberculosis Prevention. Indian Journal of Medical Research, 72(Su) (Jul). pp. 1-74. ISSN 0971-5916

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Abstract

The protective effect of BCG vaccination in man has been evaluated in a number of controlled trials. In these trials, the protection observed varied from none to 80 per cent. In view of these conflicting results, a large scale BCG trial was planned in India and the protective effect of BCG vaccinatiou evaluated in a controlled, double-blind, community trial near Madras in south India in a population of about 360,000 persons, In this trial, all individuals aged 1 yr and above were tested with 3 IU of PPD-S and 10 units of PPD-B, and simultaneously, BCG vaccines and placebo were allocated randomly to all those aged 1 mo and above. All individuals aged 10 yr and above were X-rayed, and from such persons whose photoftuorograllls were interpreted as abnormal two specimens of sputum were collected and bacteriologically examined. Intensive efforts were made, by means of regular follow-up surveys every 21/2 yr and more frequently, by selective case-finding among suspects and further by maintaining permauent diagnostic services for symptomatics, to identify all new cases of tuberculosis occurring in the community. Mutually exclusive random samples of the population were retested with tuberculin at 21/2 mo, 21/2; and 4 yr after the intake in order to evaluate the tuberculin sensitivity over time in the study population. The study population was charaterised by a high prevalence of tuberculous infection nd disease as also by a very high prevalence of uonspecific sensitivity. This report presents findings of the first 71/2 yr of follow-up. The, tuberculin sensitivity induced by BCG vaccination was highly satisfactory at 21/2 mo but waned considerably between 21/2 mo and 21/2 yr with no further waning in sensitivity thereafter. Incidence of infection was high in the study population. However, incidence of bacillary disease was more frequent among iuitial tuberculin reactors, especially among the older persons, than among uon-reactors of whom the majority were in the younger age groups. The distribution of new cases of pulmonary tuberculosis among those not infected at intake did not show any evidence of a protective effect of BCG. Certain hypotheses that may explain the findings have been discussed.

Item Type:	Article
Additional Information:	Study Paper
Subjects:	Tuberculosis > Clinical Research
Divisions:	Clinical Research
Depositing User:	Dr. Rathinasabapati R
Date Deposited:	04 Apr 2014 09:43
Last Modified:	11 Mar 2016 10:17
URI:	http://eprints.nirt.res.in/id/eprint/845

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