Sequential immunization procedure against Group B arboviruses using living attenuated 17D yellow fever virus, living attenuated Langat E5 virus, and living attenuated dengue 2 virus (New Guinea C isolate).

Abstract

Spider monkeys immunized sequentially with living 17D yellow fever virus, living attenuated Langat E5 virus, and living attenuated dengue 2 virus (New Guinea C isolate) responded with high hemagglutinating-inhibition antibody titers against 21 Group B arbovirus antigens that were tested. Such monkeys also responded with neutralizing antibodies against 20 Group B arboviruses that were tested. These vaccinated monkeys were protected against subcutaneous challenges with dengue serotypes 1, 2, 3 or 4, Russian spring-summer encephalitis virus, Kyasanur Forest Disease virus, Omsk hemorrhagic fever virus, Japanese encephalitis virus, Murray Valley encephalitis virus, West Nile virus, and Kadam virus. The protection against these viruses was based on a much lower viremia, or absence of histologic lesions in the central nervous system, or absence of an antibody booster response. The 3-virus sequential immunized spider monkeys were also protected against Modoc virus as determined by viremia studies, in spite of the fact that no detectable serum neutralizing antibodies were found in these animals at the time of challenge. The development of the sequential immunization procedure is discussed.