We have investigated efficacy of meglumine acridonacetate (Cycloferon) infrequently sick children (FSC) on the basis of serum proteomic profile dynamics; we have also studied epidemiologic efficacy of interferon inductor as a mean of non-specific immunoprophylaxis. FSC were subjects to follow up during 4-10 years. We have used recommended regimens of drug administration. Were analyzed: anamneses of FSC, clinical symptoms, infectious index calculation, stratification of children into 5 groups of FSC and separation of children with truly frequent recurrent respiratory viral diseases. On the basis of proteomic blood analyzes the following parameters of efficacy of treatment with meglumine acridonacetate were defined: expression intensity of Rho- and Ras-signaling pathways proteins. Epidemiologic efficacy of the drug was 2,9 (from 2,4 to 3,4), rate of protection--62,8% (58,5-67,1%).