Working party shares 7 point plan for control of animal-to-human diseases

So-called zoonotic pathogen diseases, variously caused by viruses, bacteria, parasites or fungi, can be naturally transmitted from animals to humans either directly through biting or scratching  or indirectly via contaminated water and food.

These zoonoses a significant number of diseases and the World Health Organisation has labelled several identified as priority pathogens on account of their epidemic potential. 

One tool now being considered is the use of transmissible vaccines within a target population to control transmission and deliver immunisation at scale. This would impact public health challenges, wildlife conservation and animal welfare, says the RVC.

But there is an ethical concern around the deliberate modification of viruses intended to spread in nature as well as technical, safety, security and regulatory issues.

The RVC assembled a multidisciplinary researchers team including bioethicists, disease ecologists, evolutionary biologists, immunologists, sociologists and virologists to assess the potential ecological and societal risks associated with the transmission of an engineered viral vaccine.

The working party recommended implementing seven commitments to underpin transmissible vaccine research and use.

These include:

• Use of naturally occurring, host-specific viruses as vectors, sourced from and returned to their natural host species after antigen insertion.
• No intentional use of genetic modifications that increase host range, pathogenicity, or transmissibility, or create secondary hazards.
• Avoidance of technologies that could plausibly be harmful if applied to a human virus.
• Staged development with defined checkpoints within ‘appropriately controlled environments’.
• Unintended spread and consequences to be monitored, with contingency plans.
• Transparent and ‘community-led’ development.
• Safety standards to mirror the strictest standards of partner nations.

Team member, RVC recent PhD graduate David Simon said the commitments were intended to increase the likelihood potential risks of vaccine transmission were outweighed by benefits to conservation, animal welfare and zoonosis prevention.

Said Simons: “Deliberately transmissible wildlife vaccines to combat endemic and emerging zoonoses are not currently in use. However, they represent a potentially vital novel technological development to improve the health of individuals living in endemic settings for several important pathogens where there is currently no effective treatment or prevention, for example Lassa fever in West Africa.

Recommendations would provide a conservative starting point that could be refined after further research, information and technology was available.

“We strongly encourage scientists and vaccine developers to integrate and advance our seven commitments for transmissible vaccines to ensure safe, transparent and equitable implementation of this exciting intervention,” added Simons.

“Identification of suitable zoonotic pathogens for targeted vaccine development is underway and the adoption of these commitments and any future commitments will ensure that implementation of this exciting technology will benefit those who need it most.”

 Pic: Pranidchakan Boonrom