Evaluating the effects of introducing Haemophilus influenzae type b vaccine in Senegal

How do governments decide which vaccines to buy now and which to postpone until prices drop in a few years? Often countries can’t afford them all, so ministers of health need to prioritize and focus on the most important, and solvable, problems first. They need reliable scientific data to make those decisions—and PATH can help.

In July 2005, the West African country of Senegal added Haemophilus influenzae type b (Hib) vaccine to its national infant immunization program. Hib disease causes severe pneumonia and meningitis. It kills 700,000 people every year, most of them young children in Africa and Asia.

Vaccination is a great way to protect babies against Hib, but vaccination programs come with different kinds of costs. To better understand the benefits and costs of introducing the Hib vaccine in Senegal—and to help other countries learn from the experience—PATH is working with the government on a comprehensive evaluation project. The study seeks to measure and document:

• The effects of Hib vaccine on bacterial meningitis and pneumonia rates in infants.
• The long-term economic benefits and costs of the vaccine.
• The vaccine’s impact on health care delivery and on immunization logistics in Senegal.

Accurate data on how Hib vaccine affects meningitis and pneumonia rates will be of great interest not only in Senegal, but in other African countries. Another important aspect of the research is comparing the costs of vaccinating against Hib with the financial and social costs of not providing vaccine. Such costs include the losses incurred when children survive Hib, but with disability, as well as the income parents lose when they must miss work to care for a seriously ill child. The economic burden of Hib-related disability has rarely been measured in the developing world, even though the information is vital for informed decision-making about the vaccine.

Photo: Richard Lord.