UK warns people with serious allergies to avoid Pfizer vaccine

British regulators warned on Wednesday that people who have a history of serious allergic reactions shouldn't receive the new Pfizer-BioNTech vaccine as they investigate two adverse reactions that occurred on the first day of the country's mass vaccination programme. The UK's Medical and Healthcare Products Regulatory Agency (MHRA) is looking into whether the reactions were linked to the vaccine. The two people affected were staff members with the National Health Service who had a history of allergies, and both are recovering. Authorities have not specified what their reactions were. In the meantime, the regulator...