A staff member shows a vial of the Pfizer-BioNTech vaccine in Ankara, Turkey, on March 31, 2021. Turkey will begin administering the Pfizer-BioNTech vaccine in the next few days, Turkish Health Minister Fahrettin Koca said Tuesday. The country started mass vaccination against COVID-19 on Jan. 14 after the authorities approved the emergency use of China's Sinovac vaccine. (Photo by Mustafa Kaya/Xinhua)

Vials of the Pfizer-BioNTech vaccine are seen in Ankara, Turkey, on March 31, 2021. Turkey will begin administering the Pfizer-BioNTech vaccine in the next few days, Turkish Health Minister Fahrettin Koca said Tuesday. The country started mass vaccination against COVID-19 on Jan. 14 after the authorities approved the emergency use of China's Sinovac vaccine. (Photo by Mustafa Kaya/Xinhua)

Pfizer-BioNTech vaccines are seen at a warehouse in Ankara, Turkey, on March 31, 2021. Turkey will begin administering the Pfizer-BioNTech vaccine in the next few days, Turkish Health Minister Fahrettin Koca said Tuesday. The country started mass vaccination against COVID-19 on Jan. 14 after the authorities approved the emergency use of China's Sinovac vaccine. (Photo by Mustafa Kaya/Xinhua)