Analysis of Immunobiological Properties of Recombinant Streptococcus pneumoniae Pneumolysin.

We compared the immunogenicity of recombinant S. pneumoniae pneumolysin (rPly) when administered with and without Al(OH) adjuvant, and evaluated the protective properties of recombinant protein in the active defense experiment. It was shown that double immunization with rPly+Al(OH) increases the levels of IgG antibodies in comparison with the control (p<0.01), while triple immunization results in a more significant increase in IgG antibody levels (p<0.001). Double immunization with rPly without Al(OH) does not induce a significant increase in antibody levels in comparison with the control, while triple immunization results in a slight but significant increase in antibody levels (p<0.05). The active defense test proved the protective activity of rPly against S. pneumoniae serotype 3 at intranasal infection.