Nearly 4400 adverse events were reported after people received the Pfizer-BioNTech Covid-19 vaccine in the US with 21 cases determined to be anaphylaxis according to a report by the Centers for Disease Control and Prevention (CDC). The US Food and Drug Administration issued an Emergency Use Authorization for Pfizer-BioNTech Covid-19 vaccine on December 11 2020 administered as two doses separated by 21 days reports Xinhua news agency. As of December 23 2020 a total of 1893360 first doses of Pfizer-BioNTech COVID-19 vaccine had been administered in the US according to the CDC report. Reports of 4393 adverse events had been