A severe bacterial infection that can trigger childhood meningitis and pneumonia has been wiped out in the Gambia by a vaccine introduced eight years ago, researchers confirmed today in The Lancet (8 July).
The bacterium, Haemophilus influenzae type b, can cause a range of symptoms known collectively as Hib disease.
The researchers say their finding has important implications for other developing countries, as the infection was eradicated despite an irregular supply of the vaccine.
Nearly 6,000 children were monitored for Hib infection between 1997, when the Gambian authorities began a comprehensive vaccination programme for babies under 12 months old, and 2002.
Cases of Hib disease in children under the age of one fell from 200 per 100,000 to zero. For children aged five years and under, incidence fell from 60 cases per 100,000 to zero.
In their paper, the researchers explain that a vaccine's theoretical effectiveness does not always translate into practice. For example, developing countries often have inadequate means of storing and transporting vaccines, which can render treatments less effective.
That the Gambia has achieved its result with an "effective but not perfect" vaccination system should encourage other developing countries to introduce the vaccine into their immunisation programmes, say the researchers.
The World Health Organization estimates that Hib kills 400,000 to 700,000 people each year, most of them in children under five years old in the developing world. Survivors of the disease can be left severely disabled, and bacterial meningitis can cause seizures, learning impairment or permanent deafness.
Richard Adegbola of the Gambian Medical Research Council Laboratories and colleagues from the Gambia, Australia and the United Kingdom conducted the study.
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