ANTIBODY FORMATION IN MEN FOLLOWING INJECTION OF FOUR TYPE-SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS

IMPROVED METHODS FOR THE PREPARATION OF THE SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS

The specific polysaccharides of Types I and V pneumococcus give sharp equivalence zones and show maximal precipitation with homologous rabbit antisera only when carefully prepared from cultures which have not been neutralized with alkali. The precipitating power of S V toward homologous rabbit antiserum falls off in 0.1 N NaOH even more rapidly than that of S I, dropping to 7 per cent of the original value in 6 days at room temperature. The alkaline solution develops a large absorption peak at 270 mµ. Directions are given for the preparation of S VII and S XII.

A quantitative antibody response of man to infection or vaccination with Pasteurella tularensis

A polysaccharide antigen, prepared from a virulent strain of Past. tularensis by phenol extraction, was employed in assaying the antibody in sera from persons recovered from infection with, or vaccinated with Past. tularensis, using the serological technique of quantitative precipitation. Antibody levels in sera of individuals vaccinated with or recovered from infection with Past. tularensis were found to resemble those observed in similar studies by other investigators, such as the antibody response to pneumococcal antigen, meningococcal polysaccharide, and blood group substances. It is suggested that the value of actively or of passively acquired antibody to an individual exposed to tularemia is dependent not on the amount of antibody alone, but also on the amount of antigen with which the antibody is capable of combining.

Pneumococcal polysaccharide vaccines: indications, efficacy and recommendations

Streptococcus pneumoniae is the primary cause of community-acquired pneumonia, meningitis in adults and otitis media in infants and children and the third cause of meningitis in infants and children. Despite the availability of effective therapeutic agents against this pathogen, mortality has remained high, particularly for infections complicated by bacteremia. For many years, there has been a plea for vaccination. The first steps, using whole bacterial vaccines, were taken during the early decades of this century in the gold mining camps of South Africa, where pneumonia was endemic. The efficacy of purified pneumococcal polysaccharide vaccines has since been demonstrated in young adults, such as gold miners and military recruits, as well as for several other groups at risk, such as institutionalized elderly, patients with sickle cell anemia or those who have undergone a splenectomy, and elderly patients with underlying conditions such as chronic obstructive pulmonary disease and chronic cardiovascular disease, but not in infants and severely immunocompromised patients. Serological studies on the immune response to inoculation of pneumococcal polysaccharide antigens have demonstrated a severely impaired antibody response in the last two groups. Therefore, development of more highly immunogenic vaccines, e.g. by linking pneumococcal polysaccharides or parts of them to protein carriers, should be continued in an attempt to offer adequate protection to those who are insufficiently protected by the current 23-valent polysaccharide vaccine. Opportunities to immunize other patients who are at risk for pneumococcal infection and are capable of responding to the current vaccine should not be missed.