An effective vaccine to prevent invasive infections caused by Haemophilus influenzae type b (Hib) bacteria has been available for more than 20 years. Hib conjugate vaccine is safe, efficacious and easy to use, and its cost-benefit ratio is high both in industrialized as well as in developing countries. In spite of this, WHO estimates that every year approximately 8 million children contract life-threatening Haemophilus infections, especially meningitis or severe pneumonia. If we want to take seriously the Millenium Development Goal of reducing the mortality of under 5-year-old children by two-thirds before the year 2015, an effective means to contribute to this would be more efficient use of Hib vaccines.