Teenagers sign up before vaccination at a vaccination point in Shanghai, east China, Aug. 14, 2021. Shanghai started vaccinating teenagers aged between 15 and 17 against the COVID-19 on Saturday. (Xinhua/Liu Ying)

Teenagers stay for medical observation after the vaccination with their parents at a vaccination point in Shanghai, east China, Aug. 14, 2021. Shanghai started vaccinating teenagers aged between 15 and 17 against the COVID-19 on Saturday. (Xinhua/Liu Ying)

A highschool student receives COVID-19 vaccine at a vaccination point in Shanghai, east China, Aug. 14, 2021. Shanghai started vaccinating teenagers aged between 15 and 17 against the COVID-19 on Saturday. (Xinhua/Liu Ying)

People line up at a vaccination point in Shanghai, east China, Aug. 14, 2021. Shanghai started vaccinating teenagers aged between 15 and 17 against the COVID-19 on Saturday. (Xinhua/Liu Ying)

Teenagers and their parents are seen at a vaccination point in Shanghai, east China, Aug. 14, 2021. Shanghai started vaccinating teenagers aged between 15 and 17 against the COVID-19 on Saturday. (Xinhua/Liu Ying)