Responses of Gibbons to Inoculation of Epstein-Barr Virus

Two gibbons (Hylobates lar) without antibodies to antigens related to Epstein-Barr virus (EBV) were inoculated with EBV by the intravenous route, and one of these also had EBV injected into both tonsils. A third animal without antibodies to EBV was injected intratonsillarly with its own leukocytes (obtained the preceding day and exposed to EBV in vitro overnight at 37 C). All three animals seroconverted after an incubation period of five weeks, and the two that had EBV injected intratonsillarly showed signs at that time of tonsillitis, which persisted for about two weeks. None of the animals developed heterophil antibody responses. These results tend to support the idea that EBV is the cause of infectious mononucleosis.