ABSTRACT
The frequent experience in the tropics of poor results of BCG vaccination is sometimes explained by a non-specific tuberculin sensitivity. The author has attempted to verify the grounds for this hypothesis and has analyzed the data collected in a course of WHO/UNICEF BCG vaccination programs in Indonesia, Burma, the Philippines, Cambodia, and Viet-Nam
Schoolchildren were tested with 5TU of the PPD preparation of RT 19-20-21. Children not reacting with an induration of at least 8-13 mm in diameter (according to the region concerned) were revaccinated and at the same time given a second tuberculin test 20 times stronger (100 TU)
Finally a further 5 TU test was given one to three months later
The findings of the last two tests were arranged in tables illustrating the correlation between them. They show that children who reacted weakly or not at all to the 100 TU before vaccination have, if anything, slightly weaker post-vaccination allergy than those who reacted strongly to 100 TU before vaccination. It therefore appears unlikely that the low-grade sensitivity can be blamed for any possible tendency for post-vaccination allergy to be weaker in tropical populations. After examining other possible causes of the phenomenon -for example, the use of vaccine attenuated by storage at too high temperatures- the author is led to the conclusion that a considerable amount of further research is needed ...(AU)
Subject(s)
Tuberculin/adverse effects , BCG Vaccine/therapy , Immunization , Tropical Climate , Hypersensitivity, Delayed , Indonesia , Myanmar , VietnamABSTRACT
The frequent experience in the tropics of poor results of BCG vaccination is sometimes explained by a non-specific tuberculin sensitivity. The author has attempted to verify the grounds for this hypothesis and has analyzed the data collected in a course of WHO/UNICEF BCG vaccination programs in Indonesia, Burma, the Philippines, Cambodia, and Viet-Nam
Schoolchildren were tested with 5TU of the PPD preparation of RT 19-20-21. Children not reacting with an induration of at least 8-13 mm in diameter (according to the region concerned) were revaccinated and at the same time given a second tuberculin test 20 times stronger (100 TU)
The findings of the last two tests were arranged in tables illustrating the correlation between them. They show that children who reacted weakly or not at all to the 100 TU before vaccination have, if anything, slightly weaker post-vaccination allergy than those who reacted strongly to 100 TU before vaccination. It therefore appears unlikely that the low-grade sensitivity can be blamed for any possible tendency for post-vaccination allergy to be weaker in tropical populations. After examining other possible causes of the phenomenon -for example, the use of vaccine attenuated by storage at too high temperatures- the author is led to the conclusion that a considerable amount of further research is needed ...(AU)
Publicado en inglés en el Bulletin World Health Organization 35(4):479-482, 1966
Finally a further 5 TU test was given one to three months later
