People sit for 30 minutes of observation after receiving COVID-19 vaccines at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a COVID-19 vaccine at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A man fills the informed consent form out before the COVID-19 vaccination at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a man with a COVID-19 vaccine at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Peng Ziyang)

People wait for receiving COVID-19 vaccines at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

People fill the informed consent form out before the COVID-19 vaccination at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

People wait for receiving COVID-19 vaccines at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

People fill the informed consent form out before the COVID-19 vaccination at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a COVID-19 vaccine at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

Men (1st R and 2nd R) leave the 30 minutes observation area after the COVID-19 vaccination at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a man with a COVID-19 vaccine at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

People enter a healthcare center for COVID-19 vaccination in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Peng Ziyang)

A medical worker injects a man with a COVID-19 vaccine at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Peng Ziyang)

A staff member (front R) leads the way for people waiting for the COVID-19 vaccination at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a man with a COVID-19 vaccine at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A medical worker injects a man with a COVID-19 vaccine at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Peng Ziyang)

People sit for 30 minutes of observation after receiving COVID-19 vaccines at a healthcare center in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Peng Ziyang)

People sit for 30 minutes of observation after receiving COVID-19 vaccines at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)

A staff member (C) leads the way for people waiting for the COVID-19 vaccination at a temporary vaccination site in Beijing, capital of China, Jan. 2, 2021. Beijing started administering COVID-19 vaccines among specific groups of people with higher infection risks. Nine groups of people aged 18 to 59 will receive the vaccine before the Spring Festival of 2021, which falls on Feb. 12. These include frontline customs inspectors of imported cold-chain goods and personnel working in the overseas and domestic transportation sector. (Xinhua/Chen Zhonghao)