A medical worker prepares a dose of COVID-19 vaccine at a vaccination site in Nankai District, north China's Tianjin, May 12, 2021. A temporary vaccination site was launched to administer the second dose of COVID-19 vaccine for more than 1,000 deliverymen at Hongqi South Road of Nankai District, north China's Tianjin. The vaccination was arranged at night, in order not to affect the couriers' delivery work during the daytime. (Xinhua/Zhao Zishuo)
