A global campaign to eliminate measles has cut deaths from the disease by 60 per cent in six years - saving more than seven million lives, doctors report today.
The disease, one of the biggest killers of children in the developing world, claimed 873,000 lives in 1999 but that fell to 354,000 in 2005, according to a joint report from the World Health Organisation (WHO) and Unicef.
Public health specialists hailed the success of the campaign, launched in 2001, which exceeded its target to halve deaths from the disease by 2005.
Forty years after measles vaccination was introduced, the WHO and Unicef have set a new target to reduce deaths by 90 per cent by 2010 from the level in 2000. They say it may even be possible to eliminate the disease.
"The main barriers remain the high infectivity of the virus (thus high vaccine coverage is needed) and appropriate strategies and resources to reach most vulnerable groups," they report in The Lancet journal.
Measles was the single most lethal infectious agent in the world until a vaccination against it was introduced in 1963. In the early 1960s, the disease claimed six million lives yearly and there were as many as 135 million cases.
Parents in Western countries where vaccination is well established are barely conscious of the threat. But in many parts of Africa, Asia and the Indian subcontinent, the disease is widely, and rightly, feared.
It suppresses the immune system, making victims already weakened by hunger, poverty or disease susceptible to complications. Pneumonia, diarrhoea and acute encephalitis are responsible for millions of measles-related deaths.
The introduction of vaccination to developing countries in the 1980s cut the death rate to an estimated 1.9 million in 1987, according to WHO estimates. During the 1990s, a target of delivering at least one dose of vaccine to at least 80 per cent of children aged nine months was set.
But by 2000, public health experts realised that despite the availability of a cheap, safe, effective vaccine for over four decades, measles still remained a child killer on a grand scale.
To tackle the problem, the WHO and Unicef targeted 45 countries hardest hit by the disease. The strategy involved ensuring high coverage of measles vaccination, a second measles jab for all children at school age to protect those who did not respond to the first dose, close monitoring of measles cases to respond to outbreaks and improved care of those with the disease.
Lara Wolfson, of the Initiative for Vaccine Research at the WHO in Geneva, and her colleagues, say in The Lancet that almost 7.5 million lives have been saved during the six years of the campaign. Cases of the disease fell 81 per cent in the western Pacific and by 75 per cent in Africa.
"If political will and financial commitments to achieving this goal are maintained and innovative strategies for linking delivery of measles vaccine with other child survival interventions (eg insecticide- treated bed nets) there is good reason to believe that this new target [of 90 per cent] can be met," they say.
Experts believe that measles could follow smallpox, which was eliminated in 1977. The disease does not infect animals and does not exist in a chronic form - it is caused by a single stable virus and there is a safe, effective vaccine against it. These four features "make elimination feasible," say David Elliman and Helen Bedford, ofGreat Ormond Street Hospital in London.
In a commentary in The Lancet they add that delivering vaccination as part of a wider strategy to treat childhood illness offers the best hope of achieving the Millennium Development Goal to reduce child mortality by two thirds by 2015 from the level in 1990.
"This more holistic approach helps to address the five conditions that make up 70 per cent of deaths in children younger than five years - respiratory infections, diarrhoea, measles, malaria and malnutrition ... The goal [of cutting these deaths by two thirds] is not only a moral imperative, but also in everybody's best long-term interests," they wrote.