Haemophilus influenzae type b (Hib) conjugate vaccine was first introduced in Africa in The Gambia in 1997 as a primary 3-dose course in infancy with no booster, and was followed by the disappearance of invasive Hib disease by 2002. A cluster of cases detected non-systematically in post-infant children in 2005-2006 raised the question of the need for a booster dose. The objective of this study was to determine the incidence of invasive Hib disease in Gambian children 14 years after the introduction of Hib conjugate vaccine.Study design
This hospital-based clinical and microbiological Hib disease surveillance in 3 hospitals in the western region of The Gambia was undertaken between October 2007 and December 2010 applying the same methods used in a previous Hib vaccine effectiveness study in 1997-2002.Results
The annual incidences of Hib meningitis and all invasive Hib disease in children aged <5 years remained below 5 cases per 100 000 children during 2008-2010. The median age of patients with any invasive Hib disease was 5 months.Conclusion
Hib conjugate vaccination as a primary 3-dose course in The Gambia remains highly effective in controlling invasive Hib disease, and current data do not support the introduction of a booster dose.