Tipe 1 T-helper cells are of importance in development of multiple sclerosis (MS). Copaxone (TEVA, Israel) is one of the preventive drugs, which modifies T-helpers activity. Thirty-three patients with MS were treated by copaxone for 2 years and 13 patients--for 3 years. Clinical and immunological parameters were examined: amount of CD3+, CD4+, CD8+, CD16+, CD22+, CD95+, CD25+ lymphocytes, HLA-D+ cells, IgG, IgA, IgM and phagocytosis. During the treatment course, mean rate of relapses decreased from the pretreatment value from 1.26 +/- 0.11 to 0.59 +/- 0.11 in the first year and 0.28 +/- 0.07 in the second one. After 3 years no relapses were observed in 13 patients. Relapse rate was the highest in the first 3-6 months. But after 3 months there was an increase of CD22+ cells that persisted for all the period of the study. After a year of the treatment, a level of IgM, IgG, IgA and CD95+ cells has raised significantly, with decreasing of a number of CD4+ and CD8+ cells. The authors suggest that immunological shift is related to mechanism of copaxone action determining its positive effect i.e. reducing of frequency of MS relapses.