Merck's molnupiravir should not be approved.

Molnupiravir is, to put it in clear terms, a potentially dangerous and virus-enhancing drug. It is not an effective antiviral medication outside of the confined conditions of cell culture and hamster cages.

The problem with molnupiravir (MOV) is its mechanism of action: It creates mutations in the coronavirus genome as the virus replicates. This is bad to people at low levels, because mutations are what creates variants such as Delta or Omicron.

MOV can be bad to the virus in particular conditions: If you can trap the virus in an environment with high enough MOV for long enough time, then all copies of the virus in that environment will accumulate mutations that break some important function of a viral protein.

The key thing to appreciate is you can create the conditions for MOV to work in a petri dish and in lab animals in a cage, but you cannot do it reliably in human patients. And then when you don't, what you get are viruses that are mutated but not dead.

And then from there, any mutations that benefit the virus, e.g. by evading antibodies from vaccines or prior infection or by making it more contagious, will expand, no matter how rare they are. That's natural selection.