A woman receives a dose of the Chinese Sinopharm vaccine as country begins mass vaccination for the coronavirus disease (COVID-19), in Belgrade, Serbia, January 21, 2021. [Photo/Agencies]

Medical supplies donated by the Chinese government are seen at the Budapest Liszt Ferenc International Airport in Budapest, Hungary, on April 29, 2020. [Photo/Xinhua]

Workers download containers transporting the first batch of the Sinovac's COVID-19 vaccine at the International airport of Santiago, as the coronavirus disease (COVID-19) outbreak continues, Chile, Jan 28, 2021. [Photo/Agencies]

A staff member checks the packages of the COVID-19 inactivated vaccine at Sinovac Biotech Ltd, in Beijing, Dec 25, 2020. [Photo/Xinhua]

File photo of Rodrigo Duterte. [Photo/Agencies]

Serbian President Aleksandar Vucic (C) and China's Ambassador to Serbia Chen Bo (L) welcome the shipment of China's Sinopharm inactivated coronavirus vaccines at the Belgrade Airport, Serbia, Jan 16, 2021. [Photo/Xinhua]

A staff member displays a sample of the COVID-19 inactivated vaccine at a vaccine production plant of China National Pharmaceutical Group Co Ltd (Sinopharm) in Beijing, April 10, 2020. [Photo/Xinhua]

Turkish President Tayyip Erdogan receives a shot of the Sinovac's CoronaVac coronavirus disease vaccine at Ankara City Hospital in Ankara, Turkey, Jan 14, 2021. [Photo/Xinhua]

A staff member checks the packaging quality of inactivated COVID-19 vaccine products at a packaging plant of the Beijing Biological Products Institute Co Ltd in Beijing, capital of China, Dec 25, 2020. [Photo/Xinhua]

Indonesian President Joko Widodo receives the COVID-19 vaccine shot developed by China's biopharmaceutical company Sinovac Biotech at Presidential Palace in Jakarta, Indonesia, Jan 13, 2021. The president is the first Indonesian to be vaccinated to show that the vaccine is safe. [Photo/Xinhua]

Seychelles' President Wavel Ramkalawan receives a shot of the Sinovac's CoronaVac coronavirus disease vaccine at a hospital in the capital Victoria on Jan 10, 2020. [Photo/Xinhua]

A signage of Sinopharm is seen at the 2020 China International Fair for Trade in Services (CIFTIS), following the COVID-19 outbreak, in Beijing, Sept 5, 2020. [Photo/Agencies]

On Nov 3, 2020, Prime Minister and Vice-President of the UAE and ruler of Dubai Sheikh Mohammed bin Rashid Al Maktoum tweeted a picture of him receiving a shot of a COVID-19 vaccine. [Photo/Sheikh Mohammed's Twitter account]

Bahrain's Crown Prince Salman bin Hamad Al Khalifa volunteers in the phase lll clinical trial of the coronavirus disease vaccine in Manama, Bahrain, Sept 16, 2020. [Bahrain News Agency/Handout via REUTERS]