Impact of Haemophilus influenzae type b vaccination on the incidence of invasive Haemophilus influenzae disease in France, 15 years after its introduction

We assessed the impact of Haemophilus influenzae type b (Hib) vaccination, introduced in France in early 1993, on the incidence of invasive Haemophilus influenzae (Hi) disease up to 2008. The incidence of Hi meningitis fell from 0.9/100000 in 1991-1992 to 0.09/100 000 in 1996-2008, with a marked decline (96%) in children aged <5 years, including infants aged <3 months, from 12 to 0.4/100 000. The incidence of invasive Hi disease also decreased in children aged <15 years from 6 to 0.7/100 000, remained stable in the 15 64 years age group at about 0.5/100 000, and increased slightly from 2.0 to 2.4/100 000 in persons aged >64 years. No emergence of non-encapsulated or encapsulated non-vaccine serotypes was observed. These findings confirm the major direct impact of Hib vaccination on the incidence of Hi invasive disease in children and the indirect benefit of vaccination for infants too young to be vaccinated.