Clinical and Laboratory Investigations of Monovalent and Combined Meningococcal Polysaccharide Vaccines, Groups A and C

SummaryPurified group A and C me-ningococcal polysaccharide vaccines prepared in these laboratories caused remarkably little local or systemic reaction and were highly effective in stimulating serum bactericidal antibody in studies carried out in adults. There was no measurable reduction in immunogenicity or increase in toxic reaction when the two vaccines were given in combined form in a single dose. Maximal antibody response was obtained following a single dose of vaccine and there was no increase in titer when additional doses were given 1 and 6 months later. Both vaccines retained their immunogenic potency on storage at 4° for at least 1 year and there was no reduction in immunogenicity on storage for up to 2 weeks at 4° following rehydration in thimerosal preservative solution.The authors are greatly indebted to Joan Goshow and Joan Staub for valuable technical assistance. We wish also to acknowledge the medical assistance of Drs. Frank D. Gray, George A. Starkweather, and W. Stuart Warren, and the n...