RESUMO
Vaccines prepared from attenuated virus can cause symptomatic viral infection of the central nervous system. In the present study, dengue-2 parental and its live attenuated viruses were tested by intrathalamic and intraspinal injections in rhesus monkeys. The dengue-2 viruses were found to be only very weakly neurovirulent when injected directly into the brain or spinal cord of rhesus monkeys.
Assuntos
Animais , Anticorpos Antivirais/análise , Encefalopatias/microbiologia , Dengue/patologia , Vírus da Dengue/imunologia , Macaca mulatta , Doenças da Medula Espinal/patologia , Vacinas Atenuadas/imunologia , Vacinas Virais/imunologiaRESUMO
The neurovirulent properties of attenuated dengue-2 and yellow fever (YF) vaccines, dengue-2 (DEN-2) and Japanese encephalitis (JE) viruses were studied in crab-eating monkeys (Macaca fascicularis). Number of central nervous system sites (as proportion affected) with neurovirulence (NV) lesions were compared. The results indicate that these monkeys reliably developed NV-lesion when inoculated with either JE or YF vaccine viruses (87%). NV-lesions occurred in a minority when inoculated with DEN-2 vaccine virus, were of minimal severity (9%), were probably biologically insignificant, and were of equal or less severity than lesions produced by its parental virus (10%).