Abstract
Scrub typhus immunogens were prepared from Rickettsia tsutsugamushi strains Karp, Kato, Gilliam, Kostival, and Buie by exposing frozen infected yolk sac suspensions to 300 krad of gamma radiation. Mouse protection tests showed that each of the irradiated immunogens protected C3H/HeDub mice against high challenge levels of Karp and Gilliam, but that none of these single-strain immunogens were capable of protecting against all five of the challenge strains. Broad-spectrum protection was achieved by using combinations of three strains of irradiated rickettsiae in a vaccination regimen of three injections at 5-day intervals. A comparison of vaccination efficacy employing three such combinations (Karp-Gilliam-Kato, Karp-Kostival-Kato, and Buie-Kostival-Kato) indicated that both sequential administration of strains on successive vaccination days and multiple injections of trivalent mixtures produced protective responses superior to those obtained with single-strain immunogens. Trivalent mixtures of rickettsiae exhibited a striking synergistic effect on the immune response of C3H/HeDub mice and elicited a protective response against Kato challenge that could not be obtained with any single-strain immunogen. Mice vaccinated with the trivalent Karp-Gilliam-Kato immunogen resisted challenge with more than 10(3) 50% mouse lethal doses of Karp and Gilliam for 12 months, and were resistant to similar levels of challenge with Kato and Buie for 6 months.
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Selected References
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- Catanzaro P. J., Shirai A., Hilderbrandt P. K., Osterman J. V. Host defenses in experimental scrub typhus: histopathological correlates. Infect Immun. 1976 Mar;13(3):861–875. doi: 10.1128/iai.13.3.861-875.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg G. H., Jr, Osterman J. V. Experimental scrub typhus immunogens: gamma-irradiated and formalinized rickettsiae. Infect Immun. 1977 Jan;15(1):124–131. doi: 10.1128/iai.15.1.124-131.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eisenberg G. H., Jr, Osterman J. V. Gamma-irradiated scrub typhus immunogens: development and duration of immunity. Infect Immun. 1978 Oct;22(1):80–86. doi: 10.1128/iai.22.1.80-86.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Elisberg B. L., Sangkasuvana V., Campbell J. M., Bozeman F. M., Bodhidatta P. Physiogeographic distribution of scrub typhus in Thailand. Acta Med Biol (Niigata) 1967 Dec;15:61–67. [PubMed] [Google Scholar]
- Groves M. G., Osterman J. V. Host defenses in experimental scrub typhus: genetics of natural resistance to infection. Infect Immun. 1978 Feb;19(2):583–588. doi: 10.1128/iai.19.2.583-588.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Public Health Weekly Reports for DECEMBER 14, 1945. Public Health Rep. 1945 Dec 14;60(50):1483–1518. [PMC free article] [PubMed] [Google Scholar]
- Shirai A., Wisseman C. L., Jr Serologic classification of scrub typhus isolates from Pakistan. Am J Trop Med Hyg. 1975 Jan;24(1):145–153. doi: 10.4269/ajtmh.1975.24.145. [DOI] [PubMed] [Google Scholar]