Effectiveness of Haemophilus influenzae Type b Conjugate Vaccine Introduction Into Routine Childhood Immunization in Kenya

Abstract

Haemophilus influenzae type b (Hib) causes 3 million episodes of serious disease among children each year, leading to half a million deaths.¹ In Kilifi, Kenya, invasive H influenzae disease is responsible for 5% of inpatient deaths among young children; Streptococcus pneumoniae and malaria, by comparison, are responsible for 9% and 22% of inpatient deaths, respectively.² The efficacy of conjugate Hib vaccines was established in European and American children in 1987-1991.^3,4 The vaccines were licensed in the United States in 1991 and were rapidly introduced into wealthy countries from which Hib disease has now almost disappeared.^5,6 In 1997, in The Gambia, the efficacy of conjugate vaccine against invasive Hib disease was 95%,⁷ but the vaccine was not introduced into any other developing country in Africa. By 2000, only 2% of the global Hib disease burden was being prevented by vaccination.¹