A health worker measures the blood pressure for a resident before vaccination at a mobile COVID-19 vaccination site near Xidan business area in downtown Beijing, capital of China, April 7, 2021. Since April 1, Beijing has started to use mobile COVID-19 vaccination vehicles in its four districts to expedite vaccination. The vehicles are equipped with facilities such as computers, refrigerators and air conditioners to ensure the convenience, safety and reliability during the vaccination process. Technologies such as 5G and big data are also employed to manage vaccination with digital means and ensure the traceability of the whole process. (Xinhua/Li Xin)