I have a blister on one breast. Could this be due to my Covid vaccination received today?

Hello,

It is unlikely that a lesion on a breast is related to the vaccine received the same day. It is not a commonly observed effect

Nevertheless, some less frequent reactions can be observed and the coincidence in time makes it necessary to question.

Some people develop skin reactions. Swollen lymph nodes are also known to occur

I recommend that you consult your physician to obtain his or her opinion on the nature of this lesion and to establish a treatment plan if necessary.