The person, who had no known drug allergies, was still in the hospital on Wednesday morning under observation, according to the report. It is unknown whether they suffer from any other types of allergies. The Alaska resident's reaction was reportedly similar to anaphylactic reactions two heal workers in Britain experience after receiving the Pfizer-BioNTech vaccine last week - both of whom have recovered. Of note, they both had a history of severe allergies. One, a 49-year-old woman, is allergic to eggs (which Pfizer says are not in their vaccine). The other, a 40-year-old woman is allergic to several different medications. Both routinely carry EpiPenn-like devices in case of reactions.

After the workers in Britain fell ill, authorities there initially warned against giving the vaccines to anyone with a history of severe allergic reactions. They later clarified their concerns, changing the wording from "severe allergic reactions" to specify that the vaccine should not be given to anyone who has ever had an anaphylactic reaction to a food, medicine or vaccine. That type of reaction to a vaccine is "very rare," they said. -NYT

No serious adverse effects were reported during Pfizer's US trial involving over 40,000 participants, aside from aches, fevers and other 'minor' side effects.

Headaches all around

As Bloomberg notes, the first hiccups in the distribution of Pfizer's vaccine are just beginning - including a holdup on the delivery of 3,900 shots to two states, and the announcement that roughly 900,000 fewer doses would be delivered next week than were shipped this week.

Four delivery trays of the Pfizer-BioNTech SE vaccine were pulled back from delivery to California and Alabama this week and sent back to the company because they were colder than anticipated, according to Gustave Perna, the army general who serves as Operation Warp Speed's chief operations officer.