That being said. A strict timeline of benadryl seems to have saved my partner from the worst of her covid vaccine.
She's never had a good time with the vaccine, but the last time she was laid up for a week +. It was only in prepping for her shot yesterday that she found someone else who had a thread on bsky about vaccines triggering an MCAS reaction. So far it looks like she just has the flu-like malaise syptoms, and if that's truly the case that is wonderful news. ^_^