In his tweet, the renowned doctor shared data from the New York times and stated that Oxford-AstraZeneca COVID-19 Vaccine was used widely by a whopping 117 countries, followed by Pfizer s COVID-19 vaccine which was being used in 103 countries. Which COVID-19 Vaccine is Being Used in How Many Countries? Dr Faheem Younus Shares Country-Wise Data of Vaccines Usage; Check List.