DISCUSSION
Only 6 of 387 (1.6%), reacted moderately to severely to a COVID-19 vaccine after a previous reaction. 4 of these 6 persons have reacted severely on the previous dose. A severe immediate reaction, consisting of anaphylaxis or objectived angioedema on a Covid-19 vaccine therefore seems the only risk factor for a moderate to severe reaction on a following dose. All other patients reacted mildly or not at all and never needed epinephrine.
Most persons that had a reaction on a Covid-19 vaccine, treated with epinephrine, did not need treatment on a second dose. Some of these non-life threatening symptoms may be perceived as severe and treated by health care workers with epinephrine. As long as the person is not wheezing, you can converse normally with a person pulse and blood pressure are within normal limits it is often better to reassure the patient and do not give any treatment. Therefore we advise only referring persons to an allergist in case of objectived angioedema or anaphylaxis after a previous Covid-19 vaccine. Although In daily practice, it will be hard to implement this advice because most healthcare workers that administer the vaccines, have no experience in distinguishing between reactions that are truly life-threatening and those that appear life-threatening.