A senior citizen receives a dose of COVID-19 vaccine at a vaccination center in Rawalpindi of Pakistan's Punjab province on March 13, 2021.(Photo: Xinhua)
A senior citizen walks towards a vaccination booth at a vaccination center in Rawalpindi of Pakistan's Punjab province on March 13, 2021. (Photo: Xinhua)
A senior citizen checks information at a vaccination center in Rawalpindi of Pakistan's Punjab province on March 13, 2021. (Photo: Xinhua)
Senior citizens wait to receive COVID-19 vaccine at a vaccination center in Rawalpindi of Pakistan's Punjab province on March 13, 2021.(Photo: Xinhua)