The 88-year-old pontiff has been hospitalized for six weeks with pneumonia in both lungs. He will need to rest in the Vatican for at least two months, his doctors said.

Pope Francis made his first public appearance in more than five weeks on Sunday, waving to a crowd from his window at Rome’s Gemelli Hospital where he was hospitalized with pneumonia in both lungs since Feb.

The 88-year-old pontiff had been battling severe pneumonia.