Persistence of Pneumococcal Antibodies in Human Subjects following Vaccination

AbstractAdult persons who were given a pneumococcal polysaccharide vaccine containing 50 μg each of 12 serotypes showed an average 10-fold increase in amount of antibody to the 12 antigens (range 6- to 20-fold) 1 month after vaccination and there was an approximate average 50% decline in antibody 31/2 years later. Children who were 2 to 12 years old at the time of vaccination showed about the same antibody response to the vaccine but this was less persistent and there was about a 55% decline, on the average, after only 21 months, The findings are discussed in the light of need for revaccination and of the nature of antibody responses to polysaccharide antigens.