[Experience of application of pneumococcus vaccines for studies of humoral immunity]

Evaluate possible use of Pneumo-23 pneumococcus polysaccharide vaccine and Prevenar-7 conjugated vaccine in EIA as antigens for determination of IgG levels against capsule polysaccharides.

Solid phase EIA method with sorption on polystyrol of commercial vaccines Penumo-23 and Prevenar-7 was used in the study. Blood sera of 41 children before immunization and sera of 8 children before and after vaccination with Pneumo-23 and Prevenar-7 were analyzed. IgG level was determined in standard units (u.).

Mean level of antibodies in groups of unimmunized children against antigens of both vaccines were in the range of 52.3-69.1 u. (p > 0.05). The number of children with diagnostically significant level of antibodies (114 - 120 u.) was 2.4% in the control group (1/41) when Pneumo-23 antigens were used and 7.3% (3/41) when Prevenar-7 antigens were used. After vaccination with Pneumo-23 the fraction of diagnostically significant level of antibodies against Pneumo-23 antigens was on average higher by 1.8 times than in pre-vaccination period in 62.5% of children, and against Prevenar-7 antigens - by 1.6 times higher in 75% of children. After immunization with Prevenar-7 vaccine the level of antibodies increased by 3-4 times against antigens of both vaccines and reached diagnostically significant in 100% of cases.

Pneumo-23 and Prevenar-7 pneumococcal vaccines may be used as antigens for determination of antibodies against capsule polysaccharides of Streptococcus pneumoniae in EIA. Higher sensitivity of EIA based on Prevenar-7 allows to recommend this test for studies of postvaccination immunity in immunized with both conjugated and non-conjugated polysaccharide pneumococcal vaccines.