Philippine President Rodrigo Duterte (L) stands beside Health Secretary Francisco Duque as they present a case containing government-purchased Sinovac COVID-19 vaccines in Manila, the Philippines, on March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China. (Photos: Xinhua/Rouelle Umali)

A staff member transports cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines, March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

Philippine President Rodrigo Duterte (C) stands with Chinese Ambassador to the Philippines Huang Xilian (1st L) and other officials upon the arrival of government-purchased Sinovac COVID-19 vaccines in Manila, the Philippines, on March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

Photo taken on March 29, 2021 shows cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

Staff members transport cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines, March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

A staff member prepares to transport cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines, March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

A staff member transports cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines, March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

Philippine President Rodrigo Duterte shows boxes of Sinovac COVID-19 vaccines in Manila, the Philippines on March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.

A staff member transports cargo containing the first batch of government-purchased Sinovac COVID-19 vaccines upon their arrival in Manila, the Philippines, March 29, 2021. The Philippines on Monday received the first batch of the Sinovac COVID-19 vaccines its government has purchased from China.