We now have the technology to develop vaccines that spread themselves
Using wildlife vaccination to target other dangerous pathogens that circulate within bats and rodents – such as Ebola, Marburg, SARS and Lassa viruses – faces similar obstacles, which is compounded by the rapid population turnover and large population sizes of these animals.
A possible solution is to create vaccines that spread themselves through an animal population.
These “self-disseminating vaccines” can be developed in at least two ways. The conventional approach relies on applying a vaccine to the fur of captured animals and releasing them. When these animals return to their natural homes, social grooming results in the vaccine being ingested by other individuals, magnifying the level of immunity that can be achieved.
This shows promise for reducing the threat of rabies transmitted to humans from vampire bats, for example.
A more radical approach relies on inserting a small piece of the genome of the infectious disease agent into a benign virus that spreads naturally through the animal population. As this transmissible vaccine spreads from animal to animal, it immunises them against the target infectious disease, vastly increasing immunity within the animal population and reducing the risk of spillover to humans.
The technology for developing transmissible vaccines now exists, and field trials focused on protecting wild rabbits from a viral haemorrhagic fever using this technique have showed promising results. Efforts are now under way to develop prototypes for several important human pathogens, such as the Lassa and Ebola viruses.
Self-disseminating vaccines could be a revolutionary technology for reducing the threat of human infectious diseases that jump to us from wild animals. In addition to making wildlife vaccination feasible and cost-effective, this technology reduces the motivation to cull or exterminate ecologically important disease reservoir species, such as bats.
https://www.newscientist.com/article/mg24732960-100-we-now-have-the-technology-to-develop-vaccines-that-spread-themselves/