Impact of the pneumococcal conjugate vaccines on invasive pneumococcal disease in France, 2001-2012.

CONTEXT AND AIMS: Vaccination with the 7-valent pneumococcal conjugate vaccine (PCV7) was recommended in France in 2003 for children <2 years. The 13-valent conjugate vaccine (PCV13) replaced PCV7 in 2010. We assessed the impact of PCVs vaccination on the incidence of invasive pneumococcal diseases (IPD) in French children (0-15 years) and adults (>15 years).

METHODS: IPD rates were calculated using cases reported from 2001 to 2012 to Epibac, a laboratory network. The distribution of serotypes was assessed from invasive isolates serotyped at the National reference Centre for Pneumococci. IPD incidence rates were compared between the pre-PCV7 (2001-2002), late PCV7 (2008-2009) and post PCV13 (2012) periods.

RESULTS: The PCVs coverage increased from 56% in the 2004 birth-cohort to 94% in the 2008 and following birth-cohorts. Following PCV7 introduction, IPD incidence decreased by 19% between 2001-2002 and 2008-2009 in children <2 years, but increased in children aged 2-15 years and adults, despite a sharp decline in PCV7-IPD in all age-groups. After PCV13 introduction, IPD incidence decreased by 34% in children <5 years, by 50% in those aged 5-15 years and 15% in adults from 2008-2009 to 2012. The incidence of PCV13-Non PCV7-IPD decreased by 74% in children <5 years and by 60% in those aged 5-15 years.

CONCLUSIONS: Vaccination with PCV13 was rapidly followed by a decrease in the incidence of all-type IPD in children, in relation with a sharp decrease in the incidence of PCV13-Non PCV7-IPD. Moreover, all-type IPD decreased after PCV13 introduction in older non-vaccinated age-groups, with a shift in the distribution of serotypes. Considering the whole 2001-2012 period, the vaccination with PCV7 and PCV13 resulted in a decline in the incidence of IPD in children up to the age of 5 but not in older children and adults.