Pneumococcal antibody concentrations and carriage of pneumococci more than 3 years after infant immunization with a pneumococcal conjugate vaccine.

Background: A 9-valent pneumococcal conjugate vaccine (PCV-9), given in a 3-dose schedule, protected Gambian children against pneumococcal disease and reduced nasopharyngeal carriage of pneumococci of vaccine serotypes. We have studied the effect of a booster or delayed primary dose of 7-valent conjugate vaccine (PCV-7) on antibody and nasopharyngeal carriage of pneumococci 3-4 years after primary vaccination.

Methodology/principal Findings: We recruited a subsample of children who had received 3 doses of either PCV-9 or placebo (controls) into this follow-up study.

Immunogenicity and safety of a meningococcal A conjugate vaccine in Africans.

Background: Group A meningococci are the source of major epidemics of meningitis in Africa. An affordable, highly immunogenic meningococcal A conjugate vaccine is needed.

Methods: We conducted two studies in Africa to evaluate a new MenA conjugate vaccine (PsA-TT).

Prospects and challenges with introduction of a mono-valent meningococcal conjugate vaccine in Africa.

Epidemic meningococcal meningitis is a priority disease for prevention and control in Africa. The current World Health Organization (WHO) approach to the control of meningitis epidemics is based on early detection of cases and emergency vaccination of the population at risk with meningococcal polysaccharide (PS) vaccines. But this is a tall order for the developing nations of Africa where experts operate from an ineffective health system.

Molecular epidemiology of pneumococci obtained from Gambian children aged 2-29 months with invasive pneumococcal disease during a trial of a 9-valent pneumococcal conjugate vaccine.

Background: The study describes the molecular epidemiology of Streptococcus pneumoniae causing invasive disease in Gambian children

Methods: One hundred and thirty-two S. pneumoniae isolates were recovered from children aged 2-29 months during the course of a pneumococcal conjugate vaccine trial conducted in The Gambia of which 131 were characterized by serotyping, antibiotic susceptibility, BOX-PCR and MLST.

Results: Twenty-nine different serotypes were identified; serotypes 14, 19A, 12F, 5, 23F, and 1 were common and accounted for 58.

Immunogenicity and serotype-specific efficacy of a 9-valent pneumococcal conjugate vaccine (PCV-9) determined during an efficacy trial in The Gambia.

This study aimed to determine the immunogenicity of a 9-valent pneumococcal conjugate vaccine (PCV-9) in a subgroup of Gambian children enrolled in a large vaccine efficacy trial. To place the antibody results in context, in this paper we also report previously unpublished data on serotype-specific clinical vaccine efficacy from the main trial. In the sub-study, a single 2-4 ml venous blood specimen was collected from 212 Gambian children 4-6 weeks after the administration of a third dose of PCV-9 or placebo.