Jean E. Groover

Reduction in Functional Antibody Activity Against Streptococcus pneumoniae in Vaccinated Elderly Individuals Highly Correlates with Decreased IgG Antibody Avidity

The pneumococcal polysaccharide vaccine is recommended as a means of preventing invasive disease in the elderly. We compared responses to the 23-valent polysaccharide vaccine in 46 previously unvaccinated, healthy, institutionalized elderly persons (mean age, 85.5 years) with those in 12 healthy younger adults (mean age, 37 years) by measuring prevaccination and postvaccination serum IgG antibody concentrations (by ELISA), functional antibody activity (by opsonophagocytosis), IgG antibody avidity, and passive protection in mice. Postvaccination IgG antibody concentrations for two serotypes (6B and 19F) of the five studied (4, 6B, 14, 19F, and 23F) were significantly lower in elderly than in younger adults; however, opsonophagocytic activity was significantly reduced for all serotypes in the elderly. Sera with reduced opsonophagocytic activity (titer, <64) correlated with low IgG antibody avidity and protected mice poorly against pneumococcal challenge. In elderly persons receiving polysaccharide vaccination, there was a significant reduction in the functionality of postvaccination antibodies, and this appeared to increase with advanced age.

IgG Responses to Protein-Conjugated Pneumococcal Capsular Polysaccharides in Persons Who Are Genetically Incapable of Responding to Unconjugated Polysaccharides

We have previously shown that the capacity to make IgG to pneumococcal capsular polysaccharides (PCPs) is inherited as an autosomal, mixed codominant trait. The purpose of this study was to determine whether this genetically determined unresponsiveness could be overcome by injection of protein-conjugated pneumococcal vaccines. Seven healthy adults who had failed to produce IgG to five or more of 10 representative PCPs after receiving pneumococcal vaccine and whose parents, siblings, and/or offspring had a similar lack of responsiveness received a series of protein-conjugated polysaccharide vaccines. Excellent IgG responses to most of the PCPs tested were eventually observed in five of the seven subjects after they received octavalent diphtheria toxoid-conjugated vaccine. Administration of certain protein-conjugated PCPs leads to IgG responses in some persons who lack the capacity to respond to unconjugated PCPs.

Pneumococcal vaccination for patients with spinal cord injury

Pneumococcal vaccination is recommended for persons with increased risk for pneumococcal disease or its complications. Even though recommendations for pneumococcal vaccination of the spinal cord injury (SCI) population have not been made to date, many SCI patients may qualify for vaccination. The purpose of this study was to examine the antibody response of SCI patients to polyvalent pneumococcal vaccine. Immunoglobulin G antibodies to five commonly infecting pneumococcal capsular polysaccharides were determined in 40 SCI patients and in an age-matched control of 40 able-bodied persons before and 4 to 6 weeks after vaccination. There were no significant differences in the mean antibody levels and the percentage of persons who responded to the five capsular polysaccharides in the SCI versus control groups. Among SCI patients, the antibody response was generally not affected by age, time since injury, or level of lesion. The antibody response to pneumococcal vaccination in SCI patients seems adequate.