21 May 2013
Dr Heidi J Larson
Former Associate Fellow, Centre on Global Health Security


The global map of recent measles outbreaks tells a story of politics, human conflict, bad science, weak health systems, and the power of beliefs. It also tells the story of a persisting virus which has so far been cleverer than humankind, despite the 50-year availability of an affordable, safe and highly effective vaccine.

Factors that are contributing to the global spread of measles include: Syrian refugees on the move, a failing health system in Pakistan, in addition to conflicts and violence, a generation of children in the UK who were not vaccinated against MMR because of Andrew Wakefield’s misleading study based on bad science, and a book published in Australia that celebrates 'Melanie’s Marvellous Measles' encouraging children to embrace measles as 'natural'.

In a new paper published in Lancet Infectious Diseases, analysis found that while 69% of the media and social media reports collected globally were overall positive about vaccines and vaccination programmes, 31% were negative. Among those reports that were positive, the largest portion were about new vaccine development and introduction (33%). But there are concerns about vaccine delivery issues, vaccine safety, and the majority of scepticism relates to philosophical, religious or other beliefs about existing vaccines. 

The power of belief systems against scientific evidence - which the paper refers to as the 'global burden of belief' - is a growing challenge to the scientific and public health community. Notions of what constitutes 'evidence' are highly varied, as are perceptions of risk. Most concerning is complacency due to low-to-no perceived risk of disease, which contributes not only to some deciding not to vaccinate against measles, but was also a barrier in 2009 to H1N1 vaccine acceptance globally and remains a challenge for the last mile of polio eradication. When a disease is not evident, the sentiment is often, ‘why take even the smallest risk posed by a vaccine?’ And even in countries where polio is still endemic, yet far less visible - Afghanistan, Pakistan and Nigeria - many have questioned why the repeated rounds of polio vaccine are needed when there are other more visibly pressing issues such as clean water and sanitation.

Alongside the mass polio vaccination campaigns in Pakistan, mass measles vaccination campaigns are also being conducted in response to the over 25,400 measles cases reported and nearly 150 measles-related deaths among children in the first four months of 2013. Recent news reports suggest that Saudi Arabia may impose a Hajj ban on unvaccinated Pakistani pilgrims to prevent the importation of measles. The threats of Pakistan exporting vaccine-preventable diseases are real - in 2011, China faced the consequences of still unmanaged polio in Pakistan and imported their first cases of polio (Pakistan strain) since 1999. 

In European countries where health systems are more intact - albeit variable - and delivery issues are less an issue than in resource-poor settings, measles has still surged in recent years. According to the April 2013 European Centre for Disease Prevention and Control (ECDC) measles surveillance report, of the 95% of measles cases where vaccination status was known, 82% were unvaccinated. In other words, reasons for non-vaccination were not primarily due to access, as access is not a significant problem in European countries, but beliefs and perceptions seemed to be the more important driver. 

There are grains of truth in the public mind. As a successful mode of prevention, immunization has indeed reduced the global burden of vaccine-preventable disease. Vaccine preventable diseases are less visible in many settings. As one Rabbi commented in a news article on the recent measles outbreaks in London’s Jewish Orthodox community, 'the perception (is) that measles is a 'healthy illness'. It's not seen as a great danger to health'. In the UK, the combination of less measles disease and lowered perception of disease risk, combined with vaccine scares following the now debunked Wakefield research, and the consequent heightened vaccine-risk perceptions, all led MMR vaccine coverage to plummet. It has taken the recent serious measles outbreaks in the UK to remind the public that measles is still a very real health threat with complications that can be disabling and even fatal. More than 50,000 people have been vaccinated in Wales alone in response to the recent outbreaks. 

Measles in the world today should be a wake-up call to the consequences of under-vaccination. What is humbling is that many of those affected have either been too young or old to be vaccinated, or for other reasons have compromised immune systems. It is those who have chosen – or whose caregivers have decided – to forgo vaccination who then become the disease spreaders. 

We may be lucky to have this wake-up call, as measles is less fatal than other disease threats. 

The H7N9 virus now circulating in China or the novel coronavirus with fatal cases in Saudi Arabia and France may not allow the time to ponder a decision on whether or not to vaccinate – should we have a vaccine in time.