Pope Francis and retired Pope Benedict have received their first vaccination against COVID-19, the Vatican said on Thursday.
The two were given the jab at the Vatican, it added.
Francis, who is 84, had part of a lung removed due to an illness in his 20s, so he would be a high-risk patient if he were to contract the virus.
Pope Emeritus Benedict XVI, who is 93, also lives within the small city-state that is surrounded by Rome.
The Vatican began its vaccine roll-out on Wednesday.
It said that health-care workers, security personnel, and the elderly would be first in line, as well as personnel who have frequent contact with the public.
In recent months, there have been several Coronavirus outbreaks in the Vatican, including among members of the Swiss Guard.