BACKGROUND We recently showed that vaccination with a 7-valent pneumococcal conjugate vaccine (PCV7) followed by a 23-valent pneumococcal polysaccharide vaccine (PPSV23) failed to prevent new episodes of acute otitis media (AOM) in previously unvaccinated toddlers and children with a history of recurrent AOM. We describe in detail the impact of pneumococcal vaccinations on nasopharyngeal carria...

BACKGROUND Group A Neisseria meningitidis has been a major cause of bacterial meningitis in the sub-Saharan region of Africa in the meningitis belt. Neisseria meningitidis is an encapsulated pathogen, and antibodies against the capsular polysaccharide are protective. Polysaccharide-protein conjugate vaccines have proven to be highly effective against several different encapsulated bacterial pat...

Background: Pneumococcal vaccine provides protection against invasive pneumococcal disease in population at risk. This study was conducted to compare the antibody response to 13-valent pneumococcal conjugate vaccine and 23-valent pneumococcal polysaccharide vaccine in patients with thalassemia major. Methods: A randomized cross-over clinical trial was performed on 50 asplenic patients with t...

To estimate the effectiveness of pneumococcal polysaccharide vaccine, we serotyped isolates submitted to the Pneumococcal Sentinel Surveillance System from 1984 to 1996 from 48 vaccinated and 125 unvaccinated children 2 to 5 years of age. Effectiveness against invasive disease caused by serotypes included in the vaccine was 63%. Effectiveness against serotypes in the polysaccharide vaccine but ...

BACKGROUND Polysaccharide pneumococcal vaccine is recommended for use in HIV-infected adults in Brazil but there is uncertainty about its effectiveness in this patient population. The main objective of this study was to assess the effectiveness of the 23-valent polysaccharide pneumococcal vaccine against invasive pneumococcal infection among HIV-infected adult patients in São Paulo, Brazil. M...

The polysaccharide capsule that surrounds S. pneumoniae protects the bacteria from destruction by white blood cells and therefore is important in its ability to produce disease. There are about 90 serotypes of S. pneumoniae, classified on the basis of their antigenic differences in the capsular polysaccharide. The currently licensed polysaccharide vaccine contains 23 serotypes, but children und...

The polysaccharide capsule of serogroup C Neisseria meningitidis (MenC) has been integral to vaccine development. Licensed MenC vaccines contain the O-acetylated (OAc+) form of polysaccharide. Some MenC strains have de-O-acetylated (OAc-) polysaccharide, which may affect antibody specificity and functional activity when used in a vaccine. We evaluated an OAc-MenC conjugate-tetanus toxoid conjug...

Neisseria meningitidis (meningococcus) is a Gram-negative human pathogen that causes meningococcal diseases, such as meningococcal meningitis and meningococcal septicemia. Based on the surface capsular oligosaccharides of the organism, 13 serogroups of N. meningitidis have been identified, among which A, B, C, Y, and W135 are the major pathogenic strains. Serogroup A is the pathogen most often ...

Antibodies to a modified group B meningococcal polysaccharide vaccine were examined for antigenic and functional specificities. Bactericidal determinants were investigated by using immunoaffinity columns and competitive inhibition of bactericidal activity in an in vitro killing assay. We conclude that nearly all of the vaccine-induced bactericidal activity is specific for the native polysacchar...

The vaccine of whole cells inactivated by heat and phenol that has been used in Cuba since 1983 is highly reactogenic and has shown little epidemiological impact. A technology was developed to substitute this vaccine for a Vi Polysaccharide of new generation, competitive with those existing in the international market. The technology developed is characterized by a new medium that maximizes the...