Washington: Trials in Asia and Africa show rotavirus vaccines can save the lives of even the poorest young children and programs should begin to vaccinate as many as possible, researchers reported on Thursday.
The vaccines prevented between 39 percent and 48 percent of infections in some of the poorest countries in the world, where more than 400,000 children die from rotavirus every year.
They urged the governments of developing nations to make the vaccines a priority.
"Rotavirus vaccines have the potential to protect the lives of nearly 2 million children in the next decade alone," Dr John Victor of the Seattle-based PATH non-profit development organisation and colleagues wrote in one of two reports in the Lancet medical journal.
Rotavirus vaccines made by GlaxoSmithKline and Merck and Sanofi Aventis are now part of the regular schedule for infants in the United States and other developed countries,
The two studies show they would also be effective in places without sure supplies of clean water or medical care, where diarrhoea is one of the major killers of young children.
Victor`s team tested Merck`s RotaTeq vaccine in the rural area of Matlab in Bangladesh and urban and semi-urban parts of Vietnam.
About 2,000 babies aged one to three months got either three oral doses of the vaccine or placebo. After two years, 38 vaccinated babies got severe rotavirus infections, compared to 71 babies that got placebo, making the vaccine 48 percent effective against severe disease.
"Our main goal is to prevent the most severe disease that might lead to death in areas where treatment is inaccessible," Victor said in a statement.
Dr George Armah of the University of Ghana, along with colleagues at PATH and elsewhere, tested RotaTeq in 5,400 children in Ghana, Kenya, and Mali. There, the vaccine was 39 percent effective in preventing severe disease, and 64 percent effective in babies a year old or younger.
"In Africa, where young children are dying from diarrhoeal disease and prompt medical care is often out of reach, the need to prevent rotavirus is especially urgent," they wrote.
Rotavirus vaccination, along with programs that are about to start to vaccinate children against the most common causes of meningitis, pneumonia and other bacterial infections, "could instigate a new era of reduction of childhood disease and mortality," they wrote.
Dr Anthony Nelson of the Chinese University of Hong Kong, and Dr Roger Glass of the US National Institutes of Health said cost was a major issue.
"Reassuring governments in low-income countries that they will be able to purchase vaccine at a reasonable price, when support from the GAVI Alliance ends, will be the quickest way to encourage their introduction and to establish whether these vaccines will stand alongside smallpox, measles, and poliomyelitis vaccines in their public health benefits," they wrote in a commentary.
The Geneva-based Global Alliance for Vaccines and Immunization or GAVI brokered an Advance Market Commitment agreement in March under which Pfizer and Glaxo signed a 10-year deal to supply 60 million doses a year of cut-price pneumococcal vaccines to developing nations.
Experts hope it could pave the way for future deals on rotavirus vaccines and an experimental treatment against malaria. GAVI says it needs to raise a further USD 1.5 billion over the next 5 years to ensure the program is fully funded.