Children register for the first dose of COVID-19 vaccine at an inoculation center in Phnom Penh, Cambodia on Sept. 20, 2021. (Photo by Phearum/Xinhua)
Children register for the first dose of COVID-19 vaccine at an inoculation center in Phnom Penh, Cambodia on Sept. 20, 2021. (Photo by Phearum/Xinhua)