Human interferon-gamma protects rhesus monkeys against sporozoite-induced Plasmodium cynomolgi malaria infection.

Earlier we reported that prophylactic treatment with recombinant human interferon gamma (rHuIFN-gamma) for a prolonged duration completely suppressed experimental infection with Plasmodium cynomolgi B sporozoites in rhesus monkeys. We now show that reducing the rHuIFN-gamma treatment to three administrations given close to the time (on days -1, 0, and +1) of infection was sufficient for complete protection. Animals initially protected by rHuIFN-gamma treatment are susceptible to reinfection. Studies are in progress to understand the precise mechanism of protection afforded by HuIFN-gamma against sporozoite-induced malaria infection.