https://thenextweb.com/syndication/2020/12/14/the-risks-of-pfizers-covid-19-vaccine-for-patients-with-a-history-of-severe-allergies/

Two people in the United Kingdom have experienced an allergic reaction to the Pfizer/BioNTech COVID-19 vaccine. This led the UK medicines regulator to issue precautionary advice earlier this week that “people with a significant history of allergic reactions” should not be given this vaccine for now.

This is an appropriate cautious move. The advice may change once we understand more about what caused these reactions.