A parent checks the vaccination record of her child at a community medical service center in Changsha, central China's Hunan Province, Nov. 15, 2021. Changsha has recently launched a COVID-19 vaccination campaign for children aged 3 to 11. [Photo by Chen Zeguo/Xinhua]

A medical worker prepares a dose of COVID-19 vaccine at a community medical service center in Changsha, central China's Hunan Province, Nov. 15, 2021. Changsha has recently launched a COVID-19 vaccination campaign for children aged 3 to 11. [Photo by Chen Zeguo/Xinhua]

A medical worker checks body condition for a child before administering a dose of COVID-19 vaccine at a community medical service center in Changsha, central China's Hunan Province, Nov. 15, 2021. Changsha has recently launched a COVID-19 vaccination campaign for children aged 3 to 11. [Photo by Chen Zeguo/Xinhua]

A child receives a dose of COVID-19 vaccine at a community medical service center in Changsha, central China's Hunan Province, Nov. 15, 2021. Changsha has recently launched a COVID-19 vaccination campaign for children aged 3 to 11. [Photo by Chen Zeguo/Xinhua]

A medical worker registers information for a child after administering a dose of COVID-19 vaccine at a community medical service center in Changsha, central China's Hunan Province, Nov. 15, 2021. Changsha has recently launched a COVID-19 vaccination campaign for children aged 3 to 11. [Photo by Chen Zeguo/Xinhua]