[AndrewBissell]

This is not necessarily specific to the mRNA vaccines, but one potential consequence of population-wide deployment of a 90% effective vaccine might be to create selective pressure for a more virulent strain of Covid without actually eliminating it.

[IfOnlyYouKnew]

By that logic, we'd be ravaged by polio, the plague, tetanus, super-smart bears, and evil spirits.

We should also stop all research.

(I was going to also sarcastically suggest disbanding the military. But that actually happens to sort-of work along the lines you have in mind, because we can disarm tit-for-tat along with everyone else. So what we really need is for COVID to evolve faster, until it is capable of negotiating a truce and make strategic decisions)

[AndrewBissell]

The polio vaccine, as administered, is over 99% effective, which is an order of magnitude difference.

If what I wrote is correct I don't see how it lends itself to "stop all research" as opposed to "wait until we have a more effective vaccine." I'm not even saying it's a greater than 50% probability, but it is a risk.