The new coronavirus (SARS-CoV-2) is an RNA virus, but this type of virus generally results in an average of around 23 genetic mutations per year.
A group of Univ. College London has reported interesting findings on the effects of convalescent plasma treatment on the evolution of SARS-CoV-2 virus populations in patients with immunodeficiency COVID-19.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7781345/
For the treatments of COVID-19, Remdesivir and convalescent plasma are used, the former is administered 41 days, 54 days after onset, the latter is administered 63 days, 65 days, and on the 93rd, both are administered.
(For the therapeutic effect of convalescent plasma, there have already been a report that there is no significant difference in clinical condition or overall mortality, for example, see the paper below.)
https://pubmed.ncbi.nlm.nih.gov/33232588/)
As shown in the figure below, it is shown that the mutation of the virus population changes very dynamically by the administration of the convalescent plasma. It seems to show that the RNA virus is easy to mutate so much, and evacuate from the convalescent plasma administration.
