Carriage of Streptococcus pneumoniae 3 years after start of vaccination program, the Netherlands

• Published in: Emerging infectious diseases Vol. 17; no. 4; pp. 584 - 591
• Main Authors: Spijkerman, Judith, van Gils, Elske J M, Veenhoven, Reinier H, Hak, Eelko, Yzerman, Ed P F, van der Ende, Arie, Wijmenga-Monsuur, Alienke J, van den Dobbelsteen, Germie P J M, Sanders, Elisabeth A M
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01.04.2011; Centers for Disease Control and Prevention
• Subjects: Adult; Care and treatment; Carrier State - microbiology; Child, Preschool; Cross-Sectional Studies; Female; Health aspects; Humans; Infant; Male; Nasopharynx - microbiology; Netherlands - epidemiology; Pneumococcal infections; Pneumococcal Infections - epidemiology; Pneumococcal Infections - microbiology; Pneumococcal Infections - prevention & control; Pneumococcal vaccine; Pneumococcal Vaccines - standards; Prevalence; Prevention; Risk factors; Serotyping; Streptococcus pneumoniae; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - physiology; Vaccination; Netherlands
• ISSN: 1080-6040; 1080-6059
• DOI: 10.3201/eid1704101115

To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) program, we conducted a cross-sectional observational study on nasopharyngeal carriage of Streptococcus pneumoniae 3 years after implementation of the program in the Netherlands. We compared pneumococcal serotypes in 329 prebooster 11-month-old children, 330 fully vaccinated 24-month-old children, and 324 parents with age-matched pre-PCV7 (unvaccinated) controls (ages 12 and 24 months, n = 319 and n = 321, respectively) and 296 of their parents. PCV7 serotype prevalences before and after PCV7 implementation, respectively, were 38% and 8% among 11-month-old children, 36% and 4% among 24-month-old children, and 8% and 1% among parents. Non-PCV7 serotype prevalences were 29% and 39% among 11-month-old children, 30% and 45% among 24-month-old children, and 8% and 15% among parents, respectively; serotypes 11A and 19A were most frequently isolated. PCV7 serotypes were largely replaced by non-PCV7 serotypes. Disappearance of PCV7 serotypes in parents suggests strong transmission reduction through vaccination.