Immunogenicity and safety of a pneumococcal conjugate 7-valent vaccine in infants with sickle cell disease.

OBJECTIVES: To evaluate safety and immunogenicity of the pneumococcal 7-valent conjugate vaccine (PCV7) when administered to infants with sickle cell disease (SCD) at 2, 3, and 4 months of age with a booster dose of a 23-valent pneumococcal polysaccharide vaccine (PS-23) at 15 to 18 months of age. METHODS: This open-label multicenter study in France enrolled 2-month-old infants with SCD. Blood samples for the determination of antibody concentrations to vaccine serotypes were obtained immediately before and 1 month after the primary immunization, and before and 1 month after the PS-23 booster. Local and systemic reactions were recorded on diary cards. RESULTS: Of the 51 infants enrolled, 49 received primary immunization and 46 received the booster dose. After primary immunization > or =95% of the subjects had antibody titers > or =0.35 microg/mL for the 7 serotypes. After boosting, geometric mean concentrations were high for all serotypes, ranging from 6.32 microg/mL (serotype 18C) to 29.49 microg/mL (serotype 4). Except for 1 case after administration of the booster dose, all fevers reported were less than 39 degrees C. No vaccine-related serious adverse events were reported. CONCLUSIONS: PCV7 administered at 2, 3, and 4 months of age in infants with SCD was well-tolerated, highly immunogenic, and primed for immune memory as indicated by the dramatic response to the PS-23 dose administered at 15-18 months in this study. However, the current recommended schedule is to boost with the PCV7 at 12-15 months of age and for these high-risk children, to enlarge the protection with a subsequent PS-23 dose at 2 years of age.

Impact of pneumococcal conjugate vaccine and of reduction of antibiotic use on nasopharyngeal carriage of nonsusceptible pneumococci in children with acute otitis media.

BACKGROUND: Penicillin resistance among pneumococci has increased in the past 15 years. The implementation of widespread vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) and the reduction of inappropriate antibiotic use could help reduce antibiotic resistance. METHODS: Between September 2001 and June 2004, 89 pediatricians distributed throughout France took part in this prospective study. We obtained 1906 nasopharyngeal swabs for culture from children aged 6 to 24 months with acute otitis media (AOM). At the same time as PCV7 was introduced into the routine immunization schedule, a plan to promote judicious antibiotic use was established. We recorded the frequency of antibiotic use, as well as the dates of immunization with PCV7. RESULTS: The proportion of PCV7-vaccinated children (> or =1 dose) increased from 8.2% (year 1) to 61.4% (year 3). The proportion of children who received antibiotics within 3 months before enrollment decreased from 51.8% in year 1 to 40.9% in year 3 (P < 0.001). Overall pneumococcal carriage and carriage of PCV7 serotypes decreased during the 3-year period by 16% (P < 0.001) and 35% (P < 0.001), respectively. Rates of highly penicillin resistant strains (PRP) decreased yearly: 15.4%, 10.6%, 6.7% (P < 0.001), respectively. Risks for PRP carriage were 4.2% for immunized children who had not received antibiotics, 8.6% for those vaccinated who also had received antibiotics, 10.3% for unimmunized children who had not received antibiotics, and 16.2% for unimmunized children who had received antibiotics (P < 0.001). CONCLUSION: Implementation of PCV7, combined with a reduction in antibiotic use, in a country with a high prevalence of antibiotic-resistant pneumococci appears to have a strong impact on the carriage of penicillin nonsusceptible pneumococci in children with AOM.

Time to recommend pneumococcal vaccination for all children in Europe: experience in France.

UNLABELLED: The French decision-making processes for recommendation and introduction of infant vaccination with Prevenar reflect a public health-based dialogue between the Direction Générale de la Santé and Wyeth (Paris-La Défense, France) nurtured by open and ongoing exchanges. Three surveillance programmes are being discussed: (1) to ascertain the future impact of large-scale Prevenar vaccination on invasive pneumococcal disease incidence, (2) to follow the evolution and carriage of pneumococcus and (3) to look at the possibilities to establish an epidemiological surveillance and active "vaccinovigilance" in France (to estimate the number of adverse events that might be expected among the population targeted by the vaccination recommendation). CONCLUSION: in this way, the Direction Générale de la Santé and Wyeth are working towards the implementation of a broad-scale vaccine introduction.