Posted a video a few weeks back of a Dr. who risked everything trying to explain this ...even folks here on FR mocked it.
People are getting this vaccine thinking it makes them immune, it does nothing of the sort. If you are lucky it lessons the severity of the disease, but you can still catch it and spread it. In some cases it will trigger this response they are talking about. At best it is a very expensive therapeutic approved for emergency use.
My in-laws received their first dose of vaccine last month. As luck would have it, father in-law was infected by COVID by someone with who he worked, then gave it to my mother in-law. They both were infected by COVID no more than a week following their first vaccination dose.
FIL had symptoms like a bad flu; aches & pains, fatigue, cough. MIL had less-severe symptoms, though with everything in the news, she was imagining the worst.
I presume that the first vaccination did not yet produce the full amount of antibodies, but it may have helped some. Regardless, they have both been instructed to NOT pursue the second dose of the vaccine for another six weeks.
Speaking of therapeutics, there are some very promising antibody treatments that have received EUA as well. If the vaccine doesn't keep you from becoming infected, perhaps knowing that an antibody treatment is available might be a preferred option.