Studied was the correlation between the acid-alkaline status and the antibody production in pigs treated with the VR-2 vaccine against swine erysipelas. A progressive growth of the values of the B-system indices was established as early as the 24th hour in correlation with the higher HCO3 and CO2 values. The latter substantiated a new profile of the acid-alkaline state, which persisted up to the 10th day. The subsidiary increase in the concentration of HCO3 from the 10th to the 15th day as well as of pCO2 on the 15th day was associated with the highest percent and absolute number of B lymphocytes and 'AOK' at 10(6). This confirmed the presence of a gradual correlation between the indices of the acid-alkaline state and the B system.