A woman receives a dose of COVID-19 vaccine developed by China's Sinovac Biotech during a mass vaccine inoculation at Bang Khae Market in Bangkok, Thailand, March 19, 2021. (Xinhua/Rachen Sageamsak)

People receive COVID-19 vaccines developed by China's Sinovac Biotech during a mass vaccine inoculation at Bang Khae Market in Bangkok, Thailand, March 19, 2021. (Xinhua/Rachen Sageamsak)

A medical worker injects a dose of COVID-19 vaccine developed by China's Sinovac Biotech during a mass vaccine inoculation at Bang Khae Market in Bangkok, Thailand, March 19, 2021. (Xinhua/Rachen Sageamsak)

A medical worker prepares a dose of COVID-19 vaccine developed by China's Sinovac Biotech during a mass vaccine inoculation at Bang Khae Market in Bangkok, Thailand, March 19, 2021. (Xinhua/Rachen Sageamsak)