Quantitation of IgG antibody to Streptococcus pneumoniae vaccine by ELISA and FAST-ELISA using tyraminated antigen.

We examined two ELISA methods for measuring antibodies to Streptococcus pneumoniae using tyraminated S. pneumoniae polysaccharide types 3, 7N, 9F and 14 as antigens. The ELISA has the usual format with a relatively long incubation time whereas the FAST-ELISA has a short incubation time and employs a different solid-phase configuration. We showed that both techniques can be used for the detection of antibodies to S. pneumoniae polysaccharides. Although its analytical sensitivity is about 1/10 of that of the ELISA, the FAST-ELISA is sufficiently sensitive to distinguish protective from unprotective levels of antibodies to the types of S. pneumoniae studied. In studying pre- and post-immunization response, we showed that type 3 is the most immunogenic.