It's been discussed for at least a month as a possibility, but wasn't seen in the clinical trials, since anyone with a history of known/suspected anaphylaxis to ingredients in the vaccine was excluded from the trials, while thousands in the trial with allergies to all kinds of other agents were included (and no obvious allergic responses were noted). For the vast majority of people this is a non-issue and for the tiny minority that have some history of anaphylactic responses, they should be getting their vaccines under medical supervision, just in case and even if they have an event, they're scary, but not difficult to treat (and have no lasting effects).
This is the kind of thing that can happen when "only" 15-20K receive a vaccine - even though that sounds like a very large number it won't "find" adverse events that are on the order of 1 in 50K or 500K. Obviously, we're now seeing somewhere in the neighborhood of 10 per 1MM or 1 in 100K (6 in 556K vaccinations as of Sunday) severe allergic responses in people generally with a history of severe allergic responses (like the doc in the article) vs. the more typical ~1 in 1MM severe allergic response to vaccines.
However, people who have these kinds of reactions are usually aware of them and should discuss the risks with their doctor, although the FDA/CDC still thinks that highly allergic people can safely get the vaccine, as per below, but people with suspected anaphylactic responses to ingredients in the mRNA vaccines (with PEG being the only likely culprit and this has only been seen on very rare occasions, so it's not "proven" yet) might consider not getting the vaccine, as per the excerpt from that Times article, below. The NIH is also looking into doing a study with such highly allergic people under very controlled conditions (link below).
After the initial cases accompanying the Pfizer shots, the C.D.C. issued advice that the Pfizer and Moderna vaccines might not be appropriate for people with a history of anaphylaxis to ingredients in either injection. Anaphylaxis, which typically happens within minutes after exposure to a triggering substance, can impair breathing and cause precipitous drops in blood pressure, potentially becoming life-threatening.
The agency recommended that people with other allergies should still get their shots and wait the standard 15 minutes post-injection before leaving the vaccination site. Anyone who previously had an anaphylactic reaction to a substance, including another vaccine or injectable drug, should be monitored for an extra 15 minutes.
https://www.washingtonpost.com/heal...1001d2-431a-11eb-b0e4-0f182923a025_story.html