Residents of Shanghai will be able to make appointments for booster shots of a COVID-19 vaccine for free starting from Nov. 1, the local government said.

Vaccinations for citizens meeting requirements can be booked via the health cloud app or the Jiankangyun app from 8pm on Nov. 1. Citizens aged 70 or above need to be accompanied by their family members or volunteers during their vaccination. COVID-19 vaccines that can be used as a booster shot include the inactivated virus vaccines developed by Beijing Institute of Biological Products Co., Ltd., Sinovac Biotech Ltd., and Wuhan Institute of Biological Products Co., Ltd. as well as the adenovirus vector vaccine developed by CanSino Biologics Inc.

How does COVID-19 booster shot work? After a full vaccination, neutralizing antibodies will subside after a period of time. However, the body will have already produced corresponding memory-B cells. When a booster shot is administered, it will induce memory-B cells to proliferate rapidly and produce antibodies so the human body can regain high immunity.

COVID-19 booster shots are prioritized for groups of people who have completed vaccination as follows:

Those at higher risk of contracting the virus, such as port, customs, aviation and health workers. Those planning to travel to high-risk areas. Members of the general public aged 18 and above can also apply for a booster shot at least 6 months after a full vaccination if they meet requirements.

On the day of vaccination, people need to not only bring along their ID cards, but also show the bar codes they received when booking the vaccination and sign an informed consent form before inoculation. They will undergo a 30-minute medical observation immediately after receiving the vaccine. Have a good rest and do not take strenuous exercise after vaccination on the day of vaccination.

Residents from Hong Kong, Macao and Taiwan, overseas Chinese and foreign nationals will be able to receive vaccine boosters later according to further arrangements.