Pope Francis, who is spending his fifth day in hospital for what doctors described as a "complex" respiratory infection, will not take part in this weekend's Holy Year events, the Vatican said on Tuesday.

Pope Francis has a “polymicrobial infection” of his respiratory tract that will require his hospital treatment to be changed, the Vatican said Monday, with tests indicating a “complex clinical picture” for one of the oldest popes in the church’s history.

The 88-year pontiff has been suffering from a respiratory infection for more than a week and was admitted to Rome's Gemelli Hospital on February 14.