Vaccines against measles have been around for decades and are highly effective, yet the campaign against the disease in recent years has had a bumpy ride.
The first target of the 21st century – to halve the number of deaths from measles between 1999 and 2005 – was successfully met. So the World Health Organization (WHO) set an even more ambitious goal – to reduce deaths by 90 percent from 2000 levels by 2010.
Now some elaborate number crunching by experts from WHO, the US-based Centers for Disease Control and Prevention (CDC) and Pennsylvania State University has produced disappointing news. Their study, published today in the London-based medical journal,The Lancet, concludes that although gains were rapid between 2000 and 2007, progress slowed towards the end of the decade, and the final reduction in mortality by 2010 was only 74 percent – good, but not nearly as good as had been hoped.
The executive director of the UN Children’s Fund (UNICEF), Anthony Lake, says vaccination campaigns now reach around 95 percent of all the world’s children. “This shows,” he says, “that these campaigns can succeed, even in the world’s poorest countries and most remote communities. Really this is one of the most remarkable victories in the history of public health.
“The bad news is that every day measles still claims 382 lives, the vast majority of them children under five, and every one could have been saved by two doses of a 22 cent vaccine.”
Some parts of the world have been more successful than others. Measles has been effectively eliminated in the whole of the Americas since 2002 – reduced to the point where there is no more endemic transmission of the disease, and any cases or outbreaks are the result of imported infections from other regions. China and its neighbours are also getting close to getting rid of measles.
But the disease is so infectious and so efficient at seeking out those who have not been vaccinated that even these regions cannot afford to let their levels of vaccination coverage drop. Rebecca Martin, director of the Global Immunization Division at CDC, warns against complacency. “Measles is a serious and potentially fatal disease that will return when it has the opportunity to do so. In many countries the overwhelming success we have seen with the immunization programme has led to the decreased recognition and risk perception of the severe outcome of this disease, but it is always there and will come back if given the opportunity to do so.”
Almost all the cases now seen in the USA are imported, almost half of them from Europe. Europe has had outbreaks of measles in recent years, but contributes very little to the global death toll; good health care means that very few children there die of measles. It is the very fact that Europeans do not perceive it as a deadly disease that makes some parents careless about vaccinating their children against it.
India overtakes Africa
One of the biggest surprises from the new statistical estimates is that India has now overtaken Africa as the region with the most deaths from measles – 47 percent of estimated measles mortality in 2010, while the African region contributed 36 percent. One of the report’s authors, Peter Strebel from WHO’s expanded programme on immunization, told IRIN that, again, perceptions of how deadly measles is, influenced the priority given to prevention.
“In India they have used a single dose strategy right up until 2010 and really, I think, have not seen measles as a high enough public health priority to embark on the two-dose recommended strategy. The important thing to note is that in the Indian context the risk of dying from measles is less than in the African context… Up to 10 percent of children who get measles in an African setting will die. In India it is estimated at more like 1.5 percent. So there is a big differential in the risk of dying and this may partially explain why they were not as aggressive or as eager to take on the new strategy.”
Steve Cochi of CDC adds that measles also may have lost out to polio in the scale of priorities. “There was a lot of preoccupation with achieving polio eradication in India,” he told IRIN. “But now that polio has been eradicated from India, the last case being more than a year ago, in January 2011, India has been able to step up to the plate and expand greatly its measles activities.”
This new push in India should give a fresh impetus to the drive to cut measles deaths worldwide. There is also a new WHO Strategic Plan on Measles and Rubella which will link vaccines against both diseases in a single immunization. The GAVI Alliance (formerly the Global Alliance for Vaccines and Immunization) has approved funding to immunize all children under 15 with the combined vaccine in the more than 50 countries which do not at present vaccinate against rubella. The higher age target is important, especially for girls, because rubella (sometimes known as German measles) contracted during pregnancy can cause babies to be born with congenital malformations.
WHO is not ready yet to set a target date to move from the elimination of measles in some regions to complete eradication worldwide, but the vaccines are effective, they are cheap, and experts say it is doable, so soon it may be possible to start planning for a world without measles.
[Courtesy of IRIN News]