A medical worker administers a shot of Pfizer COVID-19 vaccine to a man at Belgrade Fair makeshift vaccination center in Belgrade, Serbia, Tuesday, Aug. 17, 2021. Serbia has started administering a third, or booster, dose of four different vaccines, including Sinopharm, Pfizer, Sputnik and AstraZeneca, to people who previously were vaccinated at least 6 months ago. (AP Photo/Darko Vojinovic)
Featured Photo Galleries
