Effect of storage at 37°C on immunizing power of dried BCG vaccine

摘要

Experiments were carried out to determine the effect of storage at 37°C on the immunizing power of dried BCG vaccine. Vaccines were prepared with sodium glutamate and with sucrose, and were preserved for 6 months at 5°C and at 37°C. The preserved vaccines were then injected into four groups of 12 tuberculin-negative guinea-pigs; a fifth group of 12 non-vaccinated animals acted as controls. Six weeks after inoculation, all surviving animals were given a challenge dose of virulent human tubercle bacilli. After a further six weeks the guinea-pigs were killed, and an examination was made of the macroscopic and histological changes produced in the lymph-nodes and viscera.No significant difference in the tuberculous changes induced by the challenge infection was observed among three of the groups of vaccinated animals—namely, the two inoculated with the sodium glutamate vaccines and the one inoculated with the sucrose vaccine preserved at 5°C. The fourth vaccinated group showed greater changes than the other three, indicating that the immunizing power of the sucrose vaccine had decreased markedly during storage for 6 months at 37°C. The non-vaccinated control group, however, showed the most conspicuous changes of all the five groups.