[Influence of a complex of poly(I). poly(C) and poly-l-lysine on the course of vaccinia in monkeys]

Experiments of 22 Macaca rhesus monkeys were carried out to study the interferon-inducing and antiviral activity of poly(I) - poly(C) and of its complex with poly-l-lysine. The complexed double-stranded polyribonucleotide induced active production of serum interferon and markedly protected the monkeys inoculated intradermally with vaccinia virus (10 monkey ID50 by intradermal inoculation). The effectiveness of the protective effect depended on the schedule and routes of administration of the preparation. The greatest prophylactic and therapeutic effect was achieved by local administration of the complex in a dose of 1 mg/1 kg of body weight. This also prolonged the incubation period by 2-3 times and reduced the duration of persistence of skin lesions approximately by half. By the intravenous route, the best protection was achieved by 2 injections of 2 mg/kg at an interval of 96 hours. Four daily injections of the complex exerted virtually no effect on the course of vaccinia infection. The animals receiving the complexed poly(I) - poly(C) developed virus-neutralizing antibody to the same titres as control animals and were resistant to reinfection with vaccinia virus. A second injection of the complexed poly(I)-poly(C) 96 hours after the primary inoculation induced the same interferon production as the initial administration of the preparation. The monkeys inoculated intravenously with 2 mg/kg poly(I) - poly(C) showed no interferon in their blood serum and were also poorly protected against vaccinia virus infection.