Viruses pose a serious threat to humans and animals: invisible, elusive, and difficult to trace. How can a new virus be stopped in its tracks, so that the world is protected from epidemics such as Ebola? Professor by special appointment of Veterinary Arbovirology Jeroen Kortekaas outlines the road to more effective prevention in his inaugural address at Wageningen University.
Climate change, globalisation, and population growth are causing a rapid increase in the frequency and size of virus outbreaks all over the world. There is hardly any time to develop diagnostic tests, vaccines, and medicines in the face of an outbreak. After the Ebola outbreak in West Africa in 2015, with 11,000 deaths, the World Health Organization (WHO) concluded that the world is not prepared for outbreaks of this size and complexity.
“The recent outbreaks of Ebola in West Africa and Zika in South America have painfully demonstrated how poorly the world is prepared for epidemics,” says Prof. Jeroen Kortekaas in his inaugural address on October 18th. "We are currently unable to respond fast enough to these outbreaks."
In order to achieve more rapid response times to outbreaks, commitment is not just required from laboratories and companies that develop and produce vaccines. "It also requires the involvement of physicians, veterinarians, and epidemiologists who research illnesses and their transmission cycles. “When diseases are spread by arthropods, such as insects or ticks, additional expertise from entomologists is required," explains Prof. Kortekaas. These viruses are referred to as arthropod-borne viruses, or arboviruses. “Multidisciplinary research is essential for effectively combating arboviral diseases as the epidemiology of these diseases is very complex by being influenced by different mammalian and arthropod hosts and the environment.”
Rapid identification and response
To optimally prepare for future epidemics, we need to prioritize viral threats and to have technologies available that can be used for rapid vaccine development. To this end, the World Health Organization has developed the Blueprint global strategy and preparedness plan. “This research and development plan lists eleven known viruses, in addition to “virus X”, which is as of yet unknown, but will undoubtedly pop up somewhere,” says Professor Kortekaas. “Once it does, we need to have vaccine technologies available that enable the development and deployment of a vaccine within weeks.”
Rift Valley fever virus
Professor Kortekaas’ research group at Wageningen Bioveterinary Research in Lelystad has gained a lot of experience in the last decade with Rift Valley fever virus, which is transmitted by mosquitoes, and is fatal for young ruminants, but is dangerous for people as well. "The Ministry of Agriculture, Nature and Food Quality recognized that Rift Valley fever virus could spread outside its original habitat, following in the footsteps of other arboviruses such as West Nile virus and chikungunya virus." We had no vaccines and the available African vaccines did not meet European standards. Therefore, Wageningen Bioveterinary Research was asked to develop a vaccine. A vaccine was developed that was shown to be safe and effective in sheep, goats and cattle, which is currently being evaluated for registration in Europe.
To be better prepared for new outbreaks of arbovirus outbreaks, Professor Kortekaas suggests two strategies. Firstly, we need to know more about the arboviruses that currently cause disease in tropical regions. To achieve this, he collaborates with African colleagues. Examples are the Wesselsbron virus, which is related to the Zika virus; the Shuni virus, which is related to Schmallenberg virus that recently emerged in Europe; and the Middelburg-virus, which is related to the chikungunya virus. When more knowledge about these viruses becomes available, vaccines can be developed more quickly.
The second strategy is meant to combat viruses that are entirely unknown at the moment. Once such a virus has been introduced, extremely rapid action will have to be taken. "In order to respond to these diseases, we need to develop vaccines that target their Achilles heel. After that weak point has been found, it can be recreated and attached to artificial virus-like particles with a molecular “superglue”. A vaccine that generates the best possible protective antibodies against the virus can be developed very quickly in this fashion," concludes Professor Kortekaas.