2020/12/17 05:41
A droplet falls from a syringe after a health care worker was injected with the Pfizer-BioNTech COVID-19 vaccine at Women & Infants Hospital in Provid...
A droplet falls from a syringe after a health care worker was injected with the Pfizer-BioNTech COVID-19 vaccine at Women & Infants Hospital in Providence, R.I., Tuesday, Dec. 15, 2020. (AP Photo/David Goldman)
Catalina Gonzalez-Marques, an emergency medical physician, receives the Pfizer-BioNTech coronavirus vaccine at Brigham and Women's Hospital, Wednesday...
Catalina Gonzalez-Marques, an emergency medical physician, receives the Pfizer-BioNTech coronavirus vaccine at Brigham and Women's Hospital, Wednesday, Dec. 16, 2020, in Boston. (Brian Snyder/Pool via AP)
As COVID-19 vaccinations roll out to more and more people, health authorities are keeping close watch for any unexpected side effects.