Pneumococcal conjugate vaccine primes for polysaccharide-inducible IgG2 antibody response in children with recurrent otitis media acuta

Children with frequent recurrent episodes of otitis media may have a defici ent IgG2 antibody response to polysaccharide antigens, Five otitis-prone ch ildren were vaccinated with heptavalent pneumococcal conjugate vaccine. Whi le all had an IgG1 antibody response to all pneumococcal serotypes included in the conjugate vaccine, the IgG2 response, especially to serotypes 6B, 9 V, 19F, and 23F, was poor. However, vaccination with a 23-valent polysaccha ride vaccine 6 months after conjugate vaccination induced an 11.5- to 163-f old increase in IgG2 anti-polysaccharide antibody titers, Thus, an IgG2 pol ysaccharide antibody deficiency can be overcome by priming with a pneumococ cal conjugate vaccine followed by a booster with a polyvalent polysaccharid e vaccine.