Humans, starting with homo habilis, have been on earth for about 2 million years. Modern humans for about 200,000. The human immune system has fought off all manner of virus’. Sometimes with success, sometimes not. I suspect this little respiratory virus in the grand scheme of all of natural history is a small blip on the radar. If human survival depended on a vaccine for every little virus that we encountered, we would have been extinct a few eons ago. I think 99.999% of the unvaccinated world population that come into contact with the Wuhan laboratory flu will fare ok.