The World Health Organization has paved the way for children in Africa and Asia to be vaccinated against a diarrhoea-causing virus that kills some 500,000 children annually worldwide – 85 percent of them in African and Asian developing countries.
WHO has recommended that the vaccine for rotavirus – the leading cause of severe and often fatal diarrhoea and dehydration in under-five children – be included in national immunization programmes worldwide.
As of 2007 the organization had said more research was needed on the vaccine’s efficacy in developing countries with high child mortality; new data from clinical trials has led WHO to recommend global use of the vaccine, according to a 5 June communiqué.
The decision means poor countries in Asia and Africa can now apply for funding to include rotavirus vaccines in their national immunization programmes.
“This [vaccine] will significantly reduce mortality and morbidity of rotavirus disease,” Samba Ousmane Sow, associate professor of medicine at University of Maryland and coordinator of the Centre for Vaccine Development in Mali, told IRIN.
“For rotavirus, as with many infectious diseases, mortality is often a question of geography,” he said. “For the many people in rural Africa who cannot easily access medical care, the best and most practical solution [against this lethal illness] is to bring the vaccine to them.”
A child with rotavirus disease – which causes fever, vomiting and diarrhoea – can rapidly become dehydrated. Death from rotavirus is most common where there is no quick access to medical care, so vaccination is the most effective way to prevent severe cases and deaths, experts say.
Transmitted primarily by the faecal-oral route, the virus affects the vast majority of children globally before age three, according to WHO. The virus attacks the villi – tiny projections on the wall of the small intestine. Destruction of the affected cells reduces digestion and absorption of nutrients, resulting in diarrhoea with a loss of fluids.
The virus is resilient and traditional hygiene measures that might prevent other sanitation-related illnesses are not sufficient to limit its impact, according to PATH, an international health non-profit and one of the organizations conducting vaccine trials with WHO and the Global Alliance for Vaccines and Immunization (GAVI).
|For rotavirus, as with many infectious diseases, mortality is often a question of geography|
But given that there are many causes of diarrhoeal disease, the rotavirus vaccine must be part of a comprehensive control strategy, including improving water quality, hygiene and sanitation and providing oral rehydration solution and zinc supplements, WHO says in its communiqué.
"This [oral] vaccine, coupled with improvement of sanitation and hygiene, can shrink the gamut of diarrhoeal diseases within a population," George Armah, professor and rotavirus expert at Ghana's Noguchi Memorial Insitute for Medical Research, told IRIN in the Senegalese capital Dakar, where he was attending a meeting of the West Africa rotavirus advisory group.
"But we know that hygiene alone does not eliminate the rotavirus, hence the urgent need for this vaccine."
Armah noted that now governments will have to prepare an investment plan for including rotavirus vaccine in their immunization programmes. The GAVI Alliance uses a co-financing approach, in which countries procure some vaccines with non-GAVI funds; the intention is for countries to gradually increase their share of vaccines' cost, making immunization programmes sustainable.
The GAVI Alliance board is expected to decide at its November 2009 meeting whether all 72 GAVI-eligible countries will now become eligible to apply for funding to include the rotavirus vaccine in their immunization programmes, GAVI’s Ariane Leroy told IRIN.
Clinical trials of the vaccine are ongoing in Asia and sub-Saharan Africa, but WHO’s Strategic Advisory Group of Experts has recommended the vaccine for all populations given available evidence, WHO says.