Combined protective effect of an immunostimulatory bacterial preparation and rimantadine in experimental influenza A virus infection.

The protective effect of an immunostimulatory bacterial preparation, cytoplasmic membranes of Escherichia coli WF stable protoplast type L-forms (CM) alone and in combination with the selective antiviral drug rimantadine was evaluated in experimental influenza A/Aichi/2/68 (H3N2) virus infection in mice. In sublethal infection, CM administered intraperitoneally (i.p.) 7 days before virus exposure in a single dose of 25 mg/kg did not reduce significantly the virus lung titers. In lethal infection, CM applied in the same way weakly reduced the mortality rate. The combined application of CM with rimantadine resulted in synergistically increased protection, determined on the basis of virus lung titers, lung consolidation, mortality rates, protective indices, and survival times.