The purpose of the study was to determine the influence of the Bioimmuno administration in feed and/or immunisation with the 'Respisure' One vaccine against mycoplasmal pneumonia of swine on the development of non-specific immune response expressed by the level of acute phase proteins (APP). The study was performed on 28 piglets at the age of 4 weeks, divided into four equal groups. The biopreparations were administered according to the following pattern: group I - Bioimmuno (1 kg/50 kg of feedstuff) for 48 h and then vaccination with Respisure One (2 ml/animal i.m.), group II - Bioimmuno ( 1 kg/50 kg of feedstuff) for 48 h, group III - Respisure One (2 ml/animal i.m.), and group C (control) - PBS (2 ml/animal i.m.). Serum concentration of APP: C- reactive protein, haptoglobin, and ceruloplasmin were determined on days 0, 3, 7, 14, and 21 after immunomodulation and/or immunisation. The statistically significantly lower (P<0.05) levels of all determined APP in the experimental groups in comparison with the control group were demonstrated. This proves the protective value of the biopreparations applied in specific patterns, through their beneficial influence on the decrease in consequences of the respiratory system infections in pigs.