Serologic Distinctness of Eastern, Western, and Venezuelan Equine Encephalomyelitis Viruses.

Abstract

While the results of cross-active immunity tests recorded in the literature have suggested that some relationship may exist between the eastern, western and Venezuelan E.E. viruses, the results of intra-cerebral cross-neutralization tests, on the other hand, have indicated that these viruses are unrelated. It was considered not impossible that the discrepancy in the recorded findings by the 2 techniques may have been due to the severity and lack of sensitivity of the usual intracerebral neutralization tests, and that some inter-relationships might be found to exist if a more sensitive test were employed. Cross-neutralization tests were done in. 3-day-old mice by the subcut. route, using rabbit immune sera. Although the immune sera neutralized, millions of LD50 of their homologous virus, their neutralizing effect on the heterologous viruses was nil. Despite the high sensitivity of the test, there was no evidence, therefore, that these 3 viruses possess any antigenic components in common.