LONDON — British regulators warned that people with a history of serious allergic reactions shouldn’t receive the new Pfizer-BioNTech vaccine while they investigate two adverse reactions on the first day of the country’s mass vaccination program. The U.K.’s Medical and Healthcare Products Regulatory Agency is looking into whether the reactions […]

LONDON — British regulators warned that people with a history of serious allergic reactions shouldn’t receive the new Pfizer-BioNTech vaccine while they investigate two adverse reactions on the first day of the country’s mass vaccination program. The U.K.’s Medical and Healthcare Products Regulatory Agency is looking into whether the reactions […]