Workers transport Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation. (Photos: Xinhua)

Sri Lankan President Gotabaya Rajapaksa (4th R, front ) attends the handover ceremony of Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Cellphone photo shows workers unloading Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Sri Lankan President Gotabaya Rajapaksa (5th R, front ) attends the handover ceremony of Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

China's Ambassador to Sri Lanka Qi Zhenhong (L) and Sri Lanka's State Minister of Pharmaceutical Production, Supply and Regulation Channa Jayasumana attend an official certificate signing ceremony at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Cellphone photo shows workers unloading Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Workers transport Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Workers transport Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

Workers unload Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.

A worker unloads Sinopharm COVID-19 vaccines at the Bandaranaike International Airport in Colombo, Sri Lanka, March 31, 2021. A batch of Sinopharm vaccines arrived in Sri Lanka from China on Wednesday as part of a donation by the Chinese government to the island nation.