The recent Ebola epidemic in West Africa and the growing concerns about Zika virus infections in the Americas serve to vividly illustrate the vulnerability of even the most economically advanced societies to what is often referred to as emerging disease. With this in mind the House of Commons Select Committee in Science and Technology has recently highlighted the woeful inadequacy in the UK’s vaccine development capability as a weakness in the national capacity to respond to such unforeseen events. However, to claim that the UK is vulnerable to Ebola because we lack vaccine development capabilities misunderstands the reality of the Ebola outbreak in West Africa. The disease was able to spread due to a lack of information, and sometimes misinformation, about how the virus is passed between people. Furthermore, local healthcare systems were already struggling with a chronic lack of resources, leading frontline healthcare workers to risk their lives without protective equipment, as well as forcing people to care for their sick friends and relatives, a situation unlikely to occur in the UK. We also have a different cultural traditions with regard to burial: the African tradition of washing the dead body before burial was shown to increase the spread of virus.
Timeliness in recognising a disease outbreak and in mounting an effective response is a challenge to any society, requiring a range of multi-disciplinary skills spanning clinical acumen in the face of the unusual, through laboratory and field analyses, to handling the world’s press and media. These skills are rarely integrated, and even where they are, for example the SARS epidemic in Hong Kong in 2003, valuable time is lost in sharing information, samples and reagents across national borders. Critical time was also lost in the UK’s response to the Ebola oubreak as there was an insufficiently large cohort of laboratory and other workers with the specialised training in the handling of highly dangerous specimens and patient material.
Universities have a vital role to play in training clinicians to recognise the abnormal in the context of emerging disease as well as providing postgraduate training for clinicians, laboratory scientists and veterinarians alike to form a national skills base. Clinical training should include key skill components in disease recognition, but unfortunately many medical courses have cut training in infectious diseases over the past decade. Consequently the tropical disease base has withered to individual student electives, and those with experience of tropical diseases are no longer available to call upon.
In the last three decades over 30 new disease threats have appeared that have had a serious impact, either locally or internationally, on health-care resources. Most are the result of crossing the species barrier from animals to humans, especially from wildlife reservoirs and domesticated animals. The situation is even more complex when arthropod vectors are involved, and adaptation of viruses and bacteria to new ecosystems becomes a mounting possibility as a result of climate changes. Every populated continent has experienced new diseases, regardless of their economic status. Dengue, a distant relative of Zika virus, is an excellent case in point. Prior to 1970, epidemics were restricted to as few as nine countries. A generation later, over 55 countries now see regular outbreaks, due largely to the rapid spread of the principal arthropod vector, Aedes aegypti. However the absence of Aedes species in the UK should not allow complacency, as occasional cases of malaria occur in hot and humid summers around London’s airports due to mosquito escapes from arriving aircraft: in 1865 in Swansea there was a yellow fever outbreak. Insect vectors for other disease threats have yet to be fully evaluated but a body of opinion holds that conditions are conducive for diseases such as Rift Valley fever, a disease of both humans and cattle, to establish itself in the UK if our climate continues to change. The serious lack of support for medical entomology in the UK, however, may impact disastrously on the vital monitoring of vector competence and the likelihood of transmission to indigenous arthropod species.
Returning to the issue of vaccine development, the vaccine industry is a global business and it is unlikely that any private company would invest in production facilities to serve only the limited population the UK represents. Newer technologies such as bioengineered proteins make potential immunogens easy and rapid to produce, but scale up is costly and the regulatory issues equally complex. The UK biotechnology sector has sought to develop commercially viable vaccines but these have largely floundered on cost: an excellent example is the gas-delivered particle technology developed by Powderject in the 1990s. Even major companies have run into difficulties when producing vaccines against well-recognised threats, such as dengue. The reality is that we still do not know enough as to what actually confers protection in the vaccinated individual.
Although the availability of an Ebola vaccine is of global importance, the need for it in the UK is limited. It was not only ‘a combination of hard work and chance’ that stopped Ebola spreading beyond West Africa, but knowledge of viral dissemination routes that are easily disrupted with the right resources. Such knowledge was instrumental in determining that the UK was fully prepared to allow our healthcare workers with Ebola to return here, under 24 hour care and in full containment.
We can help prevent future outbreaks of Ebola by increasing such resources in those countries most likely to be affected, but whilst public health awareness is maintained in the UK we do not believe that we are are at great risk from this disease. We believe that prioritising inter-disciplinary research and training in emerging diseases is the highest priority to ensure the UK is ready for the ‘unexpected’ in years to come.
Elizabeth Benedikz and Colin Howard, Centre for Human Virology, University of Birmingham