Impact of infant pneumococcal vaccination on invasive pneumococcal diseases in France, 2001-2006

Vaccination with the 7-valent pneumococcal conjugate vaccine (PCV) has been recommended in France since 2003 for children under the age of two years who are at risk due to medical or living conditions. From 2006, the recommendation has been extended to all children under two years. The impact of PCV introduction on the incidence of pneumococcal meningitis and bacteraemia and on the serotype distribution in French children and other age-groups was assessed using laboratory surveillance data. The coverage with three doses of PCV was 44% in children aged 6-12 months in 2006. From 2001/2002 to 2006, the incidence of pneumococcal meningitis decreased from 8.0 to 6.0 cases per 100,000, and the incidence of pneumococcal bacteraemia decreased from 21.8 to 17.5 cases per 100,000 in children under the age of two years. For the vaccine strains, the incidence of pneumococcal meningitis and bacteraemia decreased from 20,4 to 6.0 cases per 100,000, while the incidence of pneumococcal meningitis and bacteraemia due to non-vaccine strains increased from 9.4 to 17.5 cases per 100,000 in this time period. The incidence in older children and adults did not decrease. Further expansion of PCV coverage is expected to increase the impact of the vaccination in both children and adults. However, the fact that cases caused by vaccine serotypes have been partially substituted by cases of non-vaccine serotypes is likely to reduce the overall benefit of PCV in France, should this early observation be confirmed in the future.