The main known facilitators for those virus mutations are on one hand the number of contaminations (particularly cross-species but not only), and on the other w

The main known facilitators for those virus mutations are on one hand the number of contaminations (particularly cross-species but not only), and on the other when the infection lingers in one individual due to a compromised immune system. Considering how at its worst the vaccine reduces the length of the infection, it's entirely implausible that it would also increase the likelihood of mutations. Not impossible, but very implausible. Is there a precedent for this kind of things?