Meningococcal meningitis is a severe, life-threatening infection for which no adequate vaccine exists. Current vaccines, based on the group-specific capsular polysaccharides, provide short-term protection in adults against serogroups A and C but are ineffective in infants and do not induce protection against group B strains, the predominant cause of infection in western countries, because the p...

Children with sickle cell disease were immunized with either 2 doses of 7-valent pneumococcal conjugate vaccine followed by 1 dose of 23-valent pneumococcal polysaccharide vaccine or a single dose of 23-valent vaccine. Functional antibodies to 7 vaccine serotypes were measured by a flow cytometric opsonophagocytic assay (OPA) and compared with IgG anticapsular polysaccharide antibody concentrat...

To the Editor—Richmond et al. [1] reported that the immune response to meningococcal polysaccharide vaccine (MPV) for serogroup C is suppressed in adults who have been previously immunized with the vaccine. The immune response to MPV for serogroup C has been shown to be suppressed in children !2 years old who had received a primary series of this vaccine [2, 3]. However, the vaccine is not lice...

The effect of immunization of mothers on the antibody response of their young to pneumococcal type 19F polysaccharide was studied. When 2-week-old BALB/c mice from mothers immunized with 23-valent pneumococcal vaccine during gestation were given an additional dose of the same vaccine, mouse pneumococcal antiserum, or both, they produced higher titers of antibodies to the 19F polysaccharide (1.8...

BACKGROUND The efficacy of protein-conjugated pneumococcal polysaccharide vaccines has been well characterized for children. The level of protection conferred by unconjugated polysaccharide vaccines remains less clear, particularly for elderly individuals who have had prior antigenic experience through immunization with unconjugated polysaccharide vaccines or natural exposure to Streptococcus p...

During the large epidemic of serogroups A and C meningococcal disease in Brazil, we studied the immunologic response to meningococcal polysaccharide vaccine in infants born to women vaccinated during pregnancy. Radioimmunoassay serum levels against serogroups A and C polysaccharide were more than threefold higher in vaccinated than in unvaccinated women at delivery. Cord blood levels were also ...

Streptococcus pneumoniae remains a major cause of disease worldwide; the emergence of antibiotic-resistant strains emphasizes the importance of disease prevention by use of vaccines. Recent studies have provided information that is useful for the evaluation of current vaccine recommendations. Recommendations target most people who are at high risk for invasive pneumococcal disease. However, hig...

Streptococcus pneumoniae is a pathogen that causes serious invasive infections, such as septicemia, meningitis and pneumonia in addition to mild upper respiratory tract infections. Protection from pneumococcal diseases is thought to be mediated mainly by serotype-specific antibodies to capsular antigens. Pneumococcal conjugate vaccine consists of sugars (polysaccharides) from the capsule of the...

The Hib vaccine has undergone several developments over the years. Initially an Hib polysaccharide (PRP) vacccine was developed. However, the immunological response to this vaccine was age dependent (as with other polysaccharide vaccines) with a poor response among those aged less than 2 years. Further development was undertaken; the Hib polysaccharide was conjugated to a carrier protein and th...

An immunization campaign with meningococcal ACYW135 polysaccharide vaccine was conducted in 2003 by the Saudi Arabian Ministry of Health and included a study to evaluate the immune responses in children under 5 years of age in the Al Qassim region of Saudi Arabia. Children who were >/=24 months old were given one dose of tetravalent polysaccharide vaccine, while younger children were given two ...