Protection of monkeys against Machupo virus by the passive administration of Bolivian haemorrhagic fever immunoglobulin (human origin).

Bolivian haemorrhagic fever immunoglobulin of human origin, given either prior to or shortly after experimental infection with Machupo virus, protected rhesus and cynomolgus monkeys against initial clinical illness. Some survivors developed severe neurological signs 30-47 days after virus inoculation and died 4-6 days later. Results from one of the experiments suggested that the development of neurological signs was associated more frequently with high doses of immunoglobulin than with intermediate or low doses.