Workers unload vaccines from Chinese pharmaceutical firm Sinovac on its arrival in Montevideo, Uruguay, March 16, 2021. Uruguay on Tuesday received a new batch of CoronaVac vaccines from Chinese pharmaceutical firm Sinovac to bolster its immunization drive against COVID-19. (Photos: Nicolas Celaya/Xinhua)

Workers unload vaccines from Chinese pharmaceutical firm Sinovac on its arrival in Montevideo, Uruguay, March 16, 2021. Uruguay on Tuesday received a new batch of CoronaVac vaccines from Chinese pharmaceutical firm Sinovac to bolster its immunization drive against COVID-19. (Photos: Nicolas Celaya/Xinhua)

Workers prepare to unload vaccines from Chinese pharmaceutical firm Sinovac on its arrival in Montevideo, Uruguay, March 16, 2021. Uruguay on Tuesday received a new batch of CoronaVac vaccines from Chinese pharmaceutical firm Sinovac to bolster its immunization drive against COVID-19. (Photos: Nicolas Celaya/Xinhua)