Clinical studies of an interferon inducer, polyriboinosinic-polyribocytidylic acid [poly (I)-poly (C)], in children.

Fifteen children ranging in age from one and one-half to 14 years received intravenous polyriboinosinic-polyribocytidylic acid [poly (I)-poly (C)], an interferon inducer. The patients all had serious neurologic illness either directly or circumstatially related to viral infection. Peak titers of interferon in serum ranged from 8 to 500 units/ml in response to doses of poly (I)-poly (C) of 0.1-1.0 mg/kg. Serum interferon persisted for less than or equal to 24 hr after induction. Hyporesponsiveness to a second dose of poly (I)-poly (C) persisted for seven days after initial induction, after which time full response again occurred. The half-life of poly (I) poly (C) in plasma as measured in three patients was less than 30 min. poly (I-poly(C) appears to be safe when given intravenously, but the low titers of interferon induced may limit its clinical usefulness as an antiviral drug.