Innovate UK has recently awarded a team led by Dr Michael Jarvis at the University of Plymouth UK with a £408,000 grant to develop a new vaccine against zoonosis.
About 75% of newly emerging diseases and 60% of all known human infectious diseases are likely to be zoonosis. The main idea of this new project is to develop a self-disseminating vaccine vector, called Zoonosis Barrier Vaccine (ZBV), targeting pathogens in the animal species from which they are emerging. By exploiting CRISPR/Cas9 technology, the team will aim to construct engineered viruses, which express target antigens from relevant Emerging Infectious Disease (EID) pathogens. Recombinant viruses will be then inoculated in few animals. They will spread through the whole host populations, producing EID-specific immunity in the targeted populations.
For now, the team will develop a ‘proof-of-concept’ vaccine vector, designed to halt the spread of Rift Valley Fever Virus (RVFV) and Q Fever (QF) among ruminant populations (i.e., sheep, goats and cattle). The vaccine will prevent zoonotic transmission by using an attenuated bovine herpesvirus. The recombinant herpesvirus – which will replicate only for a short period of time for safety reasons - will infect domestic and wild animals, stimulating also immunity against RVFV and QF.
The Zoonoses Barrier Vaccine strategy presents several advantages. Self-disseminating vaccines allow addressing both domestic and wild animals. The transmission of infectious diseases between wild and domestic animals is particularly relevant to EIDs, as most EIDs originate from wildlife. The vicious circle of infections and re-infections between domestic and wild animals is likely to play a pivotal role in EID epidemiological cycles. Moreover, many emerging zoonotic pathogens are poorly adapted to the human hosts in their initial phases, this offers the opportunity to halt the zoonotic transmission by targeting the animal populations, and decreasing the “probability of complete adaption to the human host with global significance”. Finally, the approval requirementsfor animal vaccines are lower than those for human vaccines, so reducing time to commercial availability.
The Zoonoses Barrier Vaccine project presents, however, some Significant communicational challenges. Infecting wild and domestic animals with recombinant viruses is the typical project, expected to fuel conspiracy theories. People might also fear a sorcerer's apprentice phenomenon, with recombinant viruses that escape from human control and become dangerous for humans and animals. Negative reactions can be also related to ecological considerations connected to the spread of engineered virus vectors in the natural environment. Finally, one should not underestimate the risk that some people may feel outrageous that livestock products for human consumption (including meat, milk, and eggs) could be theoretically “contaminated” by recombinant viruses.
Researchers should carefully consider these communicational aspects. They should develop effective communication plans, to explain the rationale of their project and the way in which they intend to mitigate potential risks (even the most unlikely ones). It is extremely important that full information on the Zoonosis Barrier Vaccine project is publicly available, in a format understandable to the public. Social media should be carefully monitored; worries, fears, myths, concerning the project should be immediately identified and addressed with appropriate counter-campaigns. Reasons of worry should be proactively addressed as they emerge. Finally, it is paramount that economic interests are completely and fully disclosed, without any ambiguity. People trust in scientists more than one usually imagine, but they do not put up with researchers who are perceived not to be fully transparent. Suspects (even remote) of conflict of interest could have devastating effects on future research in this field.
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