Tags

Type your tag names separated by a space and hit enter

Changes in the composition of the pneumococcal population and in IPD incidence in The Netherlands after the implementation of the 7-valent pneumococcal conjugate vaccine.
Vaccine. 2012 Dec 14; 30(52):7644-51.V

Abstract

The implementation of nationwide pneumococcal vaccination may lead to alterations in the pneumococcal population due to selective pressure induced by the vaccine. To monitor such changes, pneumococcal isolates causing invasive pneumococcal disease (IPD) before (2004-2005, n=1154) and after (2008-2009, n=1190) the implementation of the 7-valent pneumococcal vaccine (PCV7) in 2006 in the national immunization program (NIP) of The Netherlands were characterized by molecular typing using multiple-locus variable number tandem repeat analysis (MLVA) and capsular sequence typing (CST). The IPD incidence after the implementation of PCV7 in children <5 years of age declined, mainly due to an impressive reduction of cases caused by vaccine serotypes. In the age group of patients ≥5 years of age, the overall IPD incidence remained constant, but the IPD incidence due to vaccine serotypes declined in this age cohort as well, indicating herd immunity. IPD incidence of non-vaccine serotypes 1 and 22F isolates increased significantly and a shift in genetic background of the isolates belonging to these serotypes was observed. In general the composition of the pneumococcal population remained similar after the introduction of PCV7. Both before and after introduction of the vaccine several possible capsular switch events were noticed. We found 4 isolates from the pre-vaccination period in which the serotype 19F capsular locus had been horizontally transferred to a different genetic background. Remarkably, none of the 5 post-vaccination isolates in which we observed possible capsule switch belonged to the 19F serotype, possibly due to vaccine induced pressure. In the post-vaccine implementation period we found no evidence for capsular switch of a vaccine serotype to a non-vaccine serotype, indicating that capsular switch is not the main driving force for replacement. This study provides insights into the effects of nationwide vaccination on the pneumococcal population causing IPD.

Authors+Show Affiliations

National Institute for Public Health and the Environment, Laboratory for Infectious Diseases and Perinatal Screening, Antonie van Leeuwenhoeklaan 9, 3721 MA, Bilthoven, The Netherlands. karin.elberse@rivm.nlNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

22521844

Citation

Elberse, Karin E M., et al. "Changes in the Composition of the Pneumococcal Population and in IPD Incidence in the Netherlands After the Implementation of the 7-valent Pneumococcal Conjugate Vaccine." Vaccine, vol. 30, no. 52, 2012, pp. 7644-51.
Elberse KE, van der Heide HG, Witteveen S, et al. Changes in the composition of the pneumococcal population and in IPD incidence in The Netherlands after the implementation of the 7-valent pneumococcal conjugate vaccine. Vaccine. 2012;30(52):7644-51.
Elberse, K. E., van der Heide, H. G., Witteveen, S., van de Pol, I., Schot, C. S., van der Ende, A., Berbers, G. A., & Schouls, L. M. (2012). Changes in the composition of the pneumococcal population and in IPD incidence in The Netherlands after the implementation of the 7-valent pneumococcal conjugate vaccine. Vaccine, 30(52), 7644-51. https://doi.org/10.1016/j.vaccine.2012.04.021
Elberse KE, et al. Changes in the Composition of the Pneumococcal Population and in IPD Incidence in the Netherlands After the Implementation of the 7-valent Pneumococcal Conjugate Vaccine. Vaccine. 2012 Dec 14;30(52):7644-51. PubMed PMID: 22521844.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Changes in the composition of the pneumococcal population and in IPD incidence in The Netherlands after the implementation of the 7-valent pneumococcal conjugate vaccine. AU - Elberse,Karin E M, AU - van der Heide,Han G J, AU - Witteveen,Sandra, AU - van de Pol,Ingrid, AU - Schot,Corrie S, AU - van der Ende,Arie, AU - Berbers,Guy A M, AU - Schouls,Leo M, Y1 - 2012/04/19/ PY - 2011/12/08/received PY - 2012/03/23/revised PY - 2012/04/03/accepted PY - 2012/4/24/entrez PY - 2012/4/24/pubmed PY - 2013/4/30/medline SP - 7644 EP - 51 JF - Vaccine JO - Vaccine VL - 30 IS - 52 N2 - The implementation of nationwide pneumococcal vaccination may lead to alterations in the pneumococcal population due to selective pressure induced by the vaccine. To monitor such changes, pneumococcal isolates causing invasive pneumococcal disease (IPD) before (2004-2005, n=1154) and after (2008-2009, n=1190) the implementation of the 7-valent pneumococcal vaccine (PCV7) in 2006 in the national immunization program (NIP) of The Netherlands were characterized by molecular typing using multiple-locus variable number tandem repeat analysis (MLVA) and capsular sequence typing (CST). The IPD incidence after the implementation of PCV7 in children <5 years of age declined, mainly due to an impressive reduction of cases caused by vaccine serotypes. In the age group of patients ≥5 years of age, the overall IPD incidence remained constant, but the IPD incidence due to vaccine serotypes declined in this age cohort as well, indicating herd immunity. IPD incidence of non-vaccine serotypes 1 and 22F isolates increased significantly and a shift in genetic background of the isolates belonging to these serotypes was observed. In general the composition of the pneumococcal population remained similar after the introduction of PCV7. Both before and after introduction of the vaccine several possible capsular switch events were noticed. We found 4 isolates from the pre-vaccination period in which the serotype 19F capsular locus had been horizontally transferred to a different genetic background. Remarkably, none of the 5 post-vaccination isolates in which we observed possible capsule switch belonged to the 19F serotype, possibly due to vaccine induced pressure. In the post-vaccine implementation period we found no evidence for capsular switch of a vaccine serotype to a non-vaccine serotype, indicating that capsular switch is not the main driving force for replacement. This study provides insights into the effects of nationwide vaccination on the pneumococcal population causing IPD. SN - 1873-2518 UR - https://www.unboundmedicine.com/medline/citation/22521844/Changes_in_the_composition_of_the_pneumococcal_population_and_in_IPD_incidence_in_The_Netherlands_after_the_implementation_of_the_7_valent_pneumococcal_conjugate_vaccine_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0264-410X(12)00543-9 DB - PRIME DP - Unbound Medicine ER -