Is your child vaccinated against measles?

Scotland emerged relatively unscathed during the recent measles epidemic in England and Wales but the risk is ever-present.

Each year new cases occur in the UK as a result of imported infections. We typically don't worry overly about these cases as most children in this country are vaccinated. But, once in a while, when not enough children have been innoculated, embers of infection can spark an epidemic.

It is possible to relax about infections such as measles only when disease has been wiped out globally. However, only two diseases in history have been eradicated completely.

Millions of cases of smallpox used to occur annually, killing one-third of those infected, while rinderpest, a cattle disease, was responsible for famines and economic hardships across Africa and Asia. The campaigns that led to the global eradication of these diseases are perhaps the greatest feats of public health and veterinary medicine.

The development of reliable vaccines and sensitive surveillance were key, enabling the most remote populations to be protected and the last cases to be detected and extinguished.

Disease eradication brings massive economic benefits. It is estimated that the US recoups its investment in smallpox eradication every 26 days, quite a dividend, given that smallpox was eradicated in 1979. The global human benefit is much greater.

In the latest issue of the scientific journal, Philosophical Transactions, my colleagues and I discuss the scientific agenda for diseases targeted for elimination, including rabies, my own research focus. Polio is leading the charge, with transmission now active in only three countries. Concerted efforts have reduced its incidence by more than 99% and health planners and scientists are now deliberating over the next priorities.

Measles is among the contenders. But the last mile on the journey to eradication is the most difficult and each infection has its own set of unique obstacles. For measles, vaccine refusal is a problem, particularly in wealthy countries such as the UK where the disease has fallen from the public profile, precisely because of the success of routine vaccinations. Pockets of infection in developed countries can jeopardise progress globally.

One of the most ambitious targets is malaria, particularly difficult as it is inextricably linked to poverty. With funders such as Bill Gates, the landscape has changed, our toolbox has expanded and the science underpinning our understanding of how malaria persists and what it takes to interrupt transmission has advanced. Research shows that when a country eliminates infection locally, keeping it malaria-free should be easier. So progressive elimination country by country could ultimately lead to global eradication.

We are in an exciting era. After smallpox, it took more than 30 years for the next disease to be eradicated. Science has brought the elimination of some of the most debilitating infections within reach. In Glasgow, scientific teams are making important contributions towards the elimination of diseases such as malaria, rabies, foot-and-mouth disease, lymphatic filariasis and schistosomiasis.

Science can bring us within striking distance of eradication. But the last mile is the hardest: focus is more difficult to maintain as the public perception of the impact of what are increasingly rare diseases wanes, and circulating cases are precisely those that have evaded control measures.

Properly audited over the long term, the benefits of disease eradication hugely outweigh the economic costs. The eradication of an infectious disease is an extraordinary societal achievement, requiring continual scientific innovation, boldness and ambition from funders, far-sighted vision and commitment from our political leaders. and, of course, the continuing support of the public all the way to the finish line.

Dr Hampson is a research fellow in the Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow.