The Neurovirulence of Human and Animal Rotaviruses in Cercopithecus Monkeys

Cercopithecus monkeys were inoculated according to the specifications of neurovirulence safety test for live rubella virus vaccine with RIT 4237, a rotavirus vaccine candidate. RIT 4237 is a high passage level of the Nebraska Calf Diarrhoea Virus (NCDV). The histological findings in the first test indicated some involvement of the central nervous system. The same test was therefore repeated with RIT 4237, with a lower passage level of the NCDV strain, and with the ‘Wa’ strain, a human virus grown in tissue culture. Clinical signs and histological findings were concordant and demonstrated that all the viruses were moderately neurovirulent. As in the poliovirus neurovirulence test, the histological lesions depended mainly upon a correct inoculation in the lumbar cord. RIT 4237 was found to have the same degree of neurovirulence as the low-passage NCDV or as the ‘Wa’ strain.