What does the future hold for vaccination?
Vaccination remains one of our most effective tools in the fight to help protect animals and livestock from countless new and emerging diseases.
Through vaccination, we can improve natural immunity by stimulating the response before disease strikes, which is positive for animal welfare. Farmers can protect entire flocks or herds from disease, and from a human perspective, vaccines play a vital role in safeguarding our own health.
With this in mind, it’s no surprise that the field of vaccinology is delivering some of the most significant innovations of our time with R&D teams pioneering new ways to address the challenge of protecting both people and livestock.
Here, we look at three of them.
One Health approach to vaccine development
As the ‘One Health’ concept becomes more widely recognised, its influence is increasingly being felt in vaccine development. For example, it’s the central focus of current research into the development of a new vaccine for Rift Valley Fever Virus (RVFV) – a disease caused by a virus transmitted by mosquitoes that affects animals (commonly cattle and sheep) and humans1 – that will be co-developed for both humans and animals.
At present, there’s no licensed RVFV vaccine for humans and those widely used in livestock aren’t fit-for-purpose due to safety concerns.
Research into the viability of a human-animal RVFV vaccine uses the replication-deficient chimpanzee adenovirus vaccine as a platform to develop a vaccine for use against RVFV in livestock and people. If successful, such pioneering work could lead to further ‘One Health’ partnerships.2
Deeper collaboration on vaccine development would benefit both human and animal medicine, particularly in the control of zoonotic disease. For diseases like MERS or Rift Valley Fever, for example, the economic reward for vaccine development is often low. And so, it makes sense to pool knowledge, but also finances, across the private and the public sector for mutual human and animal benefit, which could make these medicines more viable for both populations.
Financial considerations are often a major barrier to successful vaccine development. For example, conventional systems for the production of essential proteins, used as part of the production of vaccines, are often expensive.
To help meet this challenge, researchers are looking into the use of plants as an alternative solution to vaccine development, particularly in molecular farming.
Molecular farming is a technology that uses plants to produce vaccines and antibodies. The process relies on the same method used to produce GM crops, by artificially introducing genes into plants.
The promising news is that the science is well-established, with many proofs of principle and efficacy, notably in animal vaccines. The first plant-derived pharmaceutical protein was human serum albumin discovered in 1990 in transgenic tobacco and potato plants3.
An increase in molecular farming could enable important advances in One Health vaccine development, using plant-made vaccines, reagents and therapeutics for vaccine development for such viruses as influenzas, Ebola, Rabies, Bunyaviruses (a family of single-strand, enveloped RNA viruses) and Flaviviruses (a family of positive, single-stranded, enveloped RNA viruses).4
Future tech – DNA and RNA
Another breakthrough technology for future vaccine development is the use of engineered DNA and RNA vaccines, thanks largely to accessibility and well-controlled production methods.
Approved DNA/RNA-based vaccines are beginning to see the light of day, with a handful recently approved for use in veterinary medicine. In fact, it’s the veterinaryvaccine industry that’s at the forefront of these commercial DNA vaccines. These include a vaccine against Salmon Pancreas disease and a currently non-commercialised West Nile virus (WNV) vaccine for horses.
Scientists hold high hopes for RNA and DNA vaccines, but wider use is hampered due to technical and, in particular, regulatory hurdles. Currently, most veterinary medicine approval systems simply aren’t built for these cutting-edge technologies. Companies struggle to provide the right information, while regulators lack the necessary tools for quick evaluations, which means veterinarians are left with yesterday’s tools while approvals protract.
Current hurdles aside, the history of vaccination is one characterised by almost constant evolution and innovation, since British scientist Edward Jenner developed the first vaccine for Smallpox in 1796. More than two centuries on, our sector is still providing fresh solutions to some of the biggest challenges facing both human and animal populations.
2. Warimwe, G. M. et al. Chimpanzee Adenovirus Vaccine Provides Multispecie. Protection against Rift Valley Fever. Sci. Rep. 6, 20617; doi: 10.1038/srep20617 (2016)