In a short seven months, the global community has mobilised research investments nearing one billion USD to understand and mitigate SARS-CoV-2. Driving this urgency is the high transmissibility of the virus, its perceived risk to high-income countries and the extensive global market for a treatment or vaccine. But as a zoonotic disease, COVID-19 is no anomaly. An estimated 60 per cent of infectious agents that cause disease in humans are zoonotic. Many, such as bovine tuberculosis, Rift Valley fever, brucellosis and cysticercosis, are endemic where conditions allow and have slipped off the radar of global consciousness. Termed neglected diseases, they affect the poor and marginalised in resource-poor settings where crucial livelihood strategies place people in close contact with livestock and wildlife. For private investors, the economics of developing products to address these diseases simply do not add up.
Vaccines hold huge potential, particularly where alternative measures to reduce disease outbreaks, such as cull-and-compensate or improving sanitary conditions, are challenging. In theory, several neglected livestock and zoonotic diseases are vaccine preventable, yet in many cases, suitable vaccines do not exist. Fortunately, the rapid development of new technologies and fields of research, such as recombinant DNA, bioinformatics, proteomics, synthetic biology and CRISPR-Cas, is providing new opportunities and fresh approaches to tackle old problems.
African swine fever (ASF) is a highly infectious haemorrhagic viral disease that kills almost all animals it infects and can have devastating consequences for pig farmers. Recent outbreaks in Africa and Asia have resulted in the death or culling of millions of animals, with direct costs exceeding 100 billion US dollars. Despite it being around for over a century, there is no vaccine against ASF. Researchers at the J. Craig Venter Institute (USA), the International Livestock Research Institute (ILRI) in Kenya and the Friedrich Loeffler Institute in Germany are leveraging synthetic biology to develop new live recombinant vaccine candidates for ASF. By breaking down the ASF genome, researchers can identify the role of viral proteins, including those that induce a protective immune response and those that cause disease. This provides the information to perform rapid, genome-wide modifications of the ASF virus, significantly reducing the time to develop a variety of attenuated strains that induce an immune response but do not cause disease.
By contrast, vaccines for other diseases do exist, but vary in effectiveness and quality. Haemorrhagic septicemia, an acute and often fatal disease caused by the bacteria Pasteurella multocida, is ranked in Asia as the most important contagious disease in cattle and buffaloes. The many variants of P. multocida require the development of a single, cross-protective vaccine for effective protection. Scientists at the University of Calgary and the University of Toronto in Canada, the Vaccine and Infectious Disease Organization – International Vaccine Centre (VIDO-InterVac) at the University of Sasketchewan in Canada and the Armauer Hansen Research Institute in Ethiopia are using protein engineering to do just that.
These projects are supported by the Livestock Vaccine Innovation Fund (LVIF), a seven-year CAD 57 million initiative funded by the Bill & Melinda Gates Foundation, Global Affairs Canada and Canada’s International Development Research Centre for the development, production, and commercialisation of vaccines against neglected livestock and zoonotic diseases in sub-Saharan Africa, South and South East Asia. LVIF’s funding model strategically targets research investment at multiple entry points along the vaccine development/adoption continuum from early discovery, through vaccine improvement and manufacturing, and ultimately vaccine access, delivery and adoption.
Research projects such as these directly benefit some of the world’s most disadvantaged populations, smallholder livestock farmers. Developing effective, affordable and accessible animal health products promotes food security and supports the livelihoods of the farmers who produce them, the majority of whom are women. And addressing zoonotic diseases in livestock also lowers the risk of subsequent epidemics.
But the benefits of research into vaccines for zoonotic and livestock diseases go one step further. Veterinary vaccines provide a fertile environment to troubleshoot the efficacy, manufacturing scale-up potential and regulatory considerations of new vaccine technologies. Distanced from many of the costs and regulatory hurdles of the human vaccine development stream, we can garner crucial experience in working with these new technologies. Investing in these new approaches and developing new technologies to combat neglected livestock diseases is investing in the experience we may well need to call upon to strengthen our response to the next disease outbreak when it arrives.
Justin Kemp is a Professional Development Awardee in the Animal Health Program at the International Development Research Centre (IDRC) in Ottawa, Canada.
Renée Larocque is a Senior Program Specialist at the IDRC, supporting research projects funded under the Livestock Vaccine Innovation Fund (LVIF) and the Innovative Veterinary Solutions for Antimicrobial Resistance (InnoVet-AMR) initiatives.
Kevin Tiessen is the Program Leader of the Animal Health Program at the IDRC. As part of Canada’s foreign affairs and development efforts, the IDRC invests in knowledge, innovation and solutions to improve the lives of people in the developing world.