The cooperative effect of interferon-α and ribavirin on subacute sclerosing panencephalitis (SSPE) virus infections, in vitro and in vivo

We studied the effects of two antiviral agents, human interferon-α (IFN-α) and ribavirin, on subacute sclerosing panencephalitis (SSPE) virus infections in hamsters. By intracranial administration, IFN-α alone improved the survival of infected hamsters by 20% at a dose of 6×104 IU/kg every other day for 10 days. When the dose of IFN-α was increased incrementally to 6×106 IU/kg, the survival rate increased by 70% in a dose-dependent manner. The combination of IFN-α and ribavirin had a synergic inhibitory effect on the replication of SSPE virus in cell culture. Combination of IFN-α (at a dose of 6×105 IU/kg) with ribavirin (at a dose of 1 mg/kg) completely prevented mortality. This was significantly better than either IFN-α or ribavirin monotherapy (p<0.05). Under the conditions used, IFN-α did not enhance the toxicity of ribavirin in hamsters. Intraventricular administration of high dose IFN-α and ribavirin may have potential usefulness in the treatment of patients with SSPE.