This study has some interesting ramifications.  The authors propose that further mutation may produce a variant that is completely resistant to the current Pfizer mRNA jab.  This is called vaccine escape.  Because the vaccinated here have an antibody priming of the Pfizer vaccine which now may not work, the virus may be more infective for those people as a further response from the immune system is delayed by having been vaccinated.

“A general principle in biology, vaccinology, and microbiology is that if you put living organisms like bacteria or viruses under pressure, via antibiotics, antibodies, or chemotherapeutics, for example, but don’t kill them off completely, you can inadvertently encourage their mutation into more virulent strains. Those that escape your immune system ends up surviving and selecting mutations to ensure their further survival.”

What you have then is the vaccinated creating the variants and not the unvaccinated ones.  Which is not what you have been hearing.

https://www.biorxiv.org/content/10.1101/2021.08.22.457114v1.full