3% of vaccinated people "unable to perform daily activities", CDC says

published Dec 21, 2020, last modified Feb 01, 2022

At that rate, most people not part of at-risk groups might be better off just getting COVID-19.

Source: CDC data on anaphylaxis after mRNA vaccination (mirror, archive)

It is important to note that CDC do not mean "got a bit of a chill and one degree of fever" when they speak of 3% unable to perform normal daily activities.  That term means anything from excruciating and incapacitating pains, to being unable to move and bedridden in a medical care unit.  Being sick after getting the vaccine is not unheard of.

At this rate, it is probably prudent to delay getting any mRNA vaccine until newer, safer generations of vaccines have been developed.

Keep in mind one of the cornerstones of medical ethics: if someone forces you — directly by violence, or indirectly by manipulating you — to get any medical treatment, that is an aggression against you.  If that someone forces you to get anything with the level of side effects noted here, that is tantamount to getting you sick against your will.