Does Creating Chimeras = Inventing Vectors?
If my alma mentor Paul Ewald had a grave to be lying in, he would probably be rolling over in it right now in response to how long it took me to think about what sort of role infectious disease might have to play in genetic engineering issues. Back in college, looking at everything through the lens of evolutionary medicine became second-nature. Now, not so much. It wasn’t until reading a news item about three transplant patients dying from a hamster-borne virus that I thought to wonder whether the development of chimeric creatures might facilitate interspecies disease transmission.
It’s unlikely that this would be much of a concern at the level of lab research– especially if changes are not germline, so that a chimeric population could not be created through reproduction. In any case, lab populations would likely be too small to allow for evolution of diseases that could use a chimera as an intermediary to jump between the contributing “pure” species.
But it would be a different story once sustainable breeding populations of chimerics hit the wild– or petstore supply lines (how big is the step from transgenic pets to genuine chimeras?). Still, in that scenario, only non-human species would be affected. Reading up on the potential use of chimeras to grow human organs for transplant, it seems that each animal would have to be specially designed to generate an organ that’s an exact genetic match to the human recipient. Though this practise would raise the usual interspecies risks (similar to the above, there is concern that latent viruses in one species might become activated in the other), it probably wouldn’t lead to any diseases specifically adapted to chimerics.
What the above does suggest is that there could be a risk in creating pets/wild populations of animals with human features. I can’t really think of any human features that it would be particularly amusing to have in a pet, or would represent much of an aesthetic enhancement– but suppose someone were to make a breed of cats that grow human fingers. That integration of instructions and components might be enough to spur the evolution of diseases that could cross species. Of course, it’s likely that simple moral repugnance at the idea of creating human-like animals for flippant purposes would prevent society from going down that path at all, so that we would not even get to the point where disease crossover would be an issue.
As the avian flu scare demonstrated, we still have a lot to learn about virus evolution and interspecies disease transmission. Will be interesting to see what chimerics might have to teach us in this regard…
