TY - JOUR T1 - Prompt effect of replacing the 7-valent pneumococcal conjugate vaccine with the 13-valent vaccine on the epidemiology of invasive pneumococcal disease in Norway. AU - Steens,Anneke, AU - Bergsaker,Marianne A Riise, AU - Aaberge,Ingeborg S, AU - Rønning,Karin, AU - Vestrheim,Didrik F, Y1 - 2013/10/29/ PY - 2013/06/12/received PY - 2013/09/27/revised PY - 2013/10/08/accepted PY - 2013/11/2/entrez PY - 2013/11/2/pubmed PY - 2014/7/16/medline KW - 13-Valent pneumococcal conjugate vaccine KW - 13-valent pneumococcal conjugate vaccine KW - 23-valent polysaccharide vaccine KW - 7-Valent pneumococcal conjugate vaccine KW - 7-valent pneumococcal conjugate vaccine KW - Childhood immunisation programme KW - Epidemiology KW - IPD KW - Indirect protection KW - MSIS KW - NIPH KW - NVT KW - Norwegian Immunisation Registry KW - Norwegian Institute of Public Health KW - Norwegian Surveillance System for Communicable Diseases KW - PCV13 KW - PCV13-7 KW - PCV7 KW - PPV23 KW - SYSVAK KW - Serotype replacement KW - Simpson's index of diversity KW - Streptococcus pneumoniae KW - VT KW - invasive pneumococcal disease KW - non-vaccine serotypes KW - nonPCV13 KW - nonPCV7 KW - serotypes not included in PCV13 KW - serotypes not included in PCV7 KW - six additional serotypes that are in PCV13 but not in PCV7 KW - vaccine serotypes SP - 6232 EP - 8 JF - Vaccine JO - Vaccine VL - 31 IS - 52 N2 - The introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the childhood immunisation programme in Norway in 2006 substantially decreased the incidence of vaccine-type (VT) invasive pneumococcal disease (IPD) in all age groups. Additionally, a slight increase in the non-vaccine (NVT) serotype IPD incidence (serotype replacement) was observed. After replacing PCV7 with PCV13 in 2011, a further decrease in IPD incidence is expected. However, the protection by the six additional serotypes opens new nasopharyngeal niches for colonisation, which favours conditions for serotype replacement. Close monitoring of IPD therefore remains important in order to quickly detect changes. In this observational retrospective population-based cohort study we used data notified nationally between 1 January 2004 and 31 December 2012 to determine the VT- and NVT-IPD incidences. The diversity in serotype distribution per year was analysed using the Simpson's index of diversity. Immunisation history of young children was obtained from the Norwegian Vaccination Registry to determine vaccine failure. The incidence of VT-IPD decreased in the targeted (<5 years) and non-targeted (≥5) age groups since PCV7 introduction and further decreased after the replacement with PCV13. Only two cases of vaccine failure were identified. This indicates very high effectiveness of the 2+1 schedules with PCV7 or PCV13 and suggests that non-vaccinated individuals profit through indirect protection. The decrease in incidence of PCV7-IPD in non-targeted age groups became larger in later years, indicating a lag phase for the indirect effects, and suggests that the indirect protection of PCV13 will increase in coming years. The incidence of some NVT, specifically serotypes 23B and 15A, increased after PCV13 introduction. This coincided with an increased Simpson's index of diversity in the targeted age group. As this suggests that serotype replacement is again occurring, continues monitoring of IPD is important so that adaptations to vaccine recommendations can be promptly issued. SN - 1873-2518 UR - https://www.unboundmedicine.com/medline/citation/24176490/Prompt_effect_of_replacing_the_7_valent_pneumococcal_conjugate_vaccine_with_the_13_valent_vaccine_on_the_epidemiology_of_invasive_pneumococcal_disease_in_Norway_ DB - PRIME DP - Unbound Medicine ER -