My understanding is that the spike protein already mutated in the human population, some time in January or early February. Researchers who started work on earl

My understanding is that the spike protein already mutated in the human population, some time in January or early February. Researchers who started work on earlier samples had to start over because the later spike protein version has such superior fitness that it has largely replaced the earlier version in the wild. So, stability over e.g. a month doesn't guarantee stability over longer terms.