Pneumococcal Serotypes in 4 European Countries | CDC EID

EID Journal Home > Volume 16, Number 9–September 2010

Volume 16, Number 9–September 2010
Research
Pediatric Pneumococcal Serotypes in 4 European Countries
Germaine Hanquet,1 Esther Kissling, Asuncion Fenoll, Robert George, Agnes Lepoutre, Tinne Lernout, David Tarragó, Emmanuelle Varon, and Jan Verhaegen
Author affiliations: Scientific Institute of Public Health, Brussels, Belgium (G. Hanquet, E. Kissling, T. Lernout); Belgian Knowledge Centre, Brussels (G. Hanquet); Instituto de Salud Carlos III, Madrid, Spain (A. Fenoll, D. Tarragó,); Health Protection Agency, London, UK (R. George); Institut de Veille Sanitaire, Saint Maurice, France (A. Lepoutre); Hôpital Europβen G. Pompidou, Paris, France (E. Varon); and Katholieke Universiteit Leuven Pneumococcus Reference Laboratory, Leuven, Belgium (J. Verhaegen)
Belgian Healthcare Agency, Brussels, Belgium.

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Abstract
After heptavalent pneumococcal conjugate vaccine (PCV7) was marketed in France, Spain, Belgium, and England and Wales (United Kingdom), invasive disease from non-PCV7 serotypes (NVT) increased. Adjusted serotype-specific incidences among children <15 years of age were compared between 1999–2002 (prevaccine) and 2005–2006 (postmarketing). Vaccine coverage increased to ≈32%–48% in France, Spain, and Belgium but remained <1% in England and Wales. Serotype 1 incidence rose in all age groups and countries (incidence rate ratio [IRR] 1.3–4.2; p<0.004), independently of PCV7 use, but incidence of serotypes 7F and 19A increased most in France, Spain, and Belgium (IRR 1.9–16.9 in children <5 years; p<0.001), where PCV7 coverage was greater. Vaccine-induced replacement of PCV7 serotypes possibly contributed to NVT increases, as did secular trends. New vaccines targeting these serotypes are available, but serotype dynamics needs further exploration that accounts for underreporting and prevaccine trends.

Streptococcus pneumoniae is a leading cause of meningitis and septicemia worldwide. More than 90 serotypes have been identified for S. pneumoniae, but serotype distribution differs by area and changes over time (1–3). The heptavalent pneumococcal conjugate vaccine (PCV7) targets the 7 serotypes–4, 6B, 9V, 14, 18C, 19F, and 23F–that most commonly caused pediatric invasive pneumococcal disease (IPD) in the United States. Widespread PCV7 use in the United States since 2000 led to rapid and dramatic decreases in vaccine serotypes and an overall decrease of IPD incidence (4).
In Europe, PCV7 was licensed for pediatric use in 2001 and marketed in Spain and France in 2001, England and Wales in 2002, and Belgium in 2004; the 7 serotypes accounted for 68%–77% of IPD cases in children <2 or <5 years of age (5–8). Vaccination policies from marketing to introduction of PCV7 into the universal vaccination schedule differed among countries. In Spain, Belgium, and France, vaccination aimed to reach a progressively increasing proportion of children <2 years of age, resulting in low but increasing vaccine coverage (36%–50% of young children in 2005–2006) because PCV7 was not free for all of them (6,7). In England and Wales, until late 2006 PCV7 was recommended only for medical risk groups, and population-level vaccine coverage was negligible. PCV7 was introduced in the national universal program and delivered free in France and England and Wales in 2006 and Belgium in 2007. In Spain, free universal vaccination was limited to the Madrid region beginning in 2006.

Several PCV7 postlicensure studies in the United States and European countries have described substantial increases in non-PCV7 vaccine serotypes (NVTs) (6,7,10–13). These findings raised concern that vaccine use could lead to replacement of PCV7 serotypes by NVTs, as occurred with pneumococcal carriage (14).

In Spain, Belgium, France, and England and Wales, NVT disease increased substantially between marketing and introduction of PCV7 into the universal schedule, when vaccine use was moderate in Spain, Belgium, and France and negligible in England and Wales. Considering that a 10-valent vaccine and a 13-valent conjugate vaccine are licensed in the European Union (EU), a better understanding of the dynamics of the additional serotypes is needed to help decision making on future vaccine strategies. This study describes and compares temporal trends of PCV7 serotypes and NVTs among children in 4 European countries, taking into account the levels of PCV7 use. We focused on the emergence of serotypes 1, 7F, and 19A because they were responsible for most of the NVT increase.

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