Aim: To examine the impact of Haemophilus influenzae type b (Hib) vaccine on the burden of Haemophilus influenzae (Hi) disease in New Zealand children aged under five years (under-5s).
Methods: Analysis of national mortality, hospitalisation, laboratory, and notification data.
Results: The introduction of Hib vaccine in 1994 led to a 92% decline (95%CI = 89 94%) in the hospitalisation rate of Hi meningitis for under-5s (1995 2000 compared to 1988 1993). Pre-vaccine, the Hi meningitis hospitalisation rate was 27 per 100 000 in the under-5s and this declined to 2 per 100 000. Even though Hi meningitis declined in all ethnic groups (eg down to 3 per 100 000 among Maori), there was a worsening of equity with the proportion of children hospitalised with Hi meningitis who were Maori increasing from 23% to 40% of all cases. The rate of epiglottitis hospitalisations also declined substantially (by 94%, 95%CI = 89 - 96%).
Conclusions: Hib vaccination appears to be preventing at least 80 cases of meningitis and 30 cases of epiglottitis every year in under-5s in New Zealand. But the beneficial impact of Hib vaccination has been less for Maori and so there is a need for further improvements in immunisation coverage in those populations with the highest disease burdens.