Sequential Immunization of Spider Monkeys with Three Group B Arboviruses: Yellow Fever, Langat, and Dengue-2.
YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE
Pagination or Media Count:
Spider monkeys were sequentially vaccinated with yellow fever, Langat and dengue type 2 attenuated viruses three months later they and control monkeys which had been inoculated with the vaccine substrates but no virus were subcutaneously challenged with dengue type 4. Five vaccinated and 5 control monkeys were challenged with a small dose 6 vaccinated and 5 control animals were given a large dose. As anticipated none of the animals developed signs of illness. No protection was observed against the large dose of dengue 4 virus. With the small challenge, there was a suggestion of protection at the borderline of statistical significance when the numbers of vaccinated and control animals developing viremia were compared the difference between these two groups was highly significant when the total numbers of viremia-days were compared. In spite of the slightly favorable result observed with the spider monkeys given the small challenge dose of dengue 4 virus, it must be concluded at this time that, sequential immunization to achieve protection against a group B arbovirus not included in the vaccination has not been proved by our results to be an effective and practical measure.
- Medicine and Medical Research