A medical staff member administers a dose of COVID-19 vaccine to a recipient at a vaccination station during a national COVID-19 vaccination operation in Tunis, Tunisia, on Dec. 25, 2021.Photo:Xinhua

A medical staff member works at a vaccination station during a national COVID-19 vaccination operation in Tunis, Tunisia, on Dec. 25, 2021.Photo:Xinhua

People register at a vaccination station during a national COVID-19 vaccination operation in Tunis, Tunisia, on Dec. 25, 2021.Photo:Xinhua

People line up outside a vaccination station during a national COVID-19 vaccination operation in Tunis, Tunisia, on Dec. 25, 2021.Photo:Xinhua