Photo taken on Aug. 12, 2021 shows a package of COVID-19 vaccine at Phnom Penh International Airport in Phnom Penh, Cambodia. A new batch of 3 million doses of China's Sinovac COVID-19 vaccine arrived in Phnom Penh of Cambodia on Thursday, giving another boost to the kingdom's vaccination drive. (Photo by Phearum/Xinhua)

An airport worker transports packages of COVID-19 vaccine at Phnom Penh International Airport in Phnom Penh, Cambodia on Aug. 12, 2021. A new batch of 3 million doses of China's Sinovac COVID-19 vaccine arrived in Phnom Penh of Cambodia on Thursday, giving another boost to the kingdom's vaccination drive. (Photo by Phearum/Xinhua)

An airport worker transports a package of COVID-19 vaccine at Phnom Penh International Airport in Phnom Penh, Cambodia on Aug. 12, 2021. A new batch of 3 million doses of China's Sinovac COVID-19 vaccine arrived in Phnom Penh of Cambodia on Thursday, giving another boost to the kingdom's vaccination drive. (Photo by Phearum/Xinhua)