Does Vaccination of Splenectomized Patients against Pneumococci Induce Dextran-Reactive Antibodies?

Polyvalent pneumococcal vaccine containing polysaccharides from serotypes known to be cross-reactive with dextran was used for vaccination of 72 patients either shortly before or on the average 6.25 years after splenectomy. The titer of dextran-reactive antibodies was determined by passive hemagglutination before as well as 6 weeks and 6 months after vaccination. Already prior to vaccination the patients had moderately elevated titers of these antibodies and the titer was somewhat reduced during the study period. Small intergroup differences were observed but the titers of patients who had received cytostatic and/or radiation therapy did not appear to react differently to vaccination. It is concluded that this type of vaccine does not induce dextran-reactive antibodies when given to asplenic individuals.