Workers transfer the China-donated Sinopharm COVID-19 vaccines at the Phnom Penh International Airport in Phnom Penh, Cambodia, Feb. 7, 2021. A chartered flight carrying the first batch of the China-donated Sinopharm COVID-19 vaccines arrived in Cambodia on Sunday, welcomed by Prime Minister Samdech Techo Hun Sen at the Phnom Penh International Airport. (Photo by Gao Bingnan/Xinhua)

Workers transfer the China-donated Sinopharm COVID-19 vaccines at the Phnom Penh International Airport in Phnom Penh, Cambodia, Feb. 7, 2021. A chartered flight carrying the first batch of the China-donated Sinopharm COVID-19 vaccines arrived in Cambodia on Sunday, welcomed by Prime Minister Samdech Techo Hun Sen at the Phnom Penh International Airport. (Photo by Gao Bingnan/Xinhua)

Cambodian Prime Minister Samdech Techo Hun Sen speaks during the handover ceremony of China-donated Sinopharm COVID-19 vaccines at the Phnom Penh International Airport in Phnom Penh, Cambodia, Feb. 7, 2021. A chartered flight carrying the first batch of the China-donated Sinopharm COVID-19 vaccines arrived in Cambodia on Sunday, welcomed by Prime Minister Samdech Techo Hun Sen at the Phnom Penh International Airport. (Photo by Gao Bingnan/Xinhua)

Workers transfer the China-donated Sinopharm COVID-19 vaccines at the Phnom Penh International Airport in Phnom Penh, Cambodia, Feb. 7, 2021. A chartered flight carrying the first batch of the China-donated Sinopharm COVID-19 vaccines arrived in Cambodia on Sunday, welcomed by Prime Minister Samdech Techo Hun Sen at the Phnom Penh International Airport. (Photo by Sovannara/Xinhua)