Employees of the Gemelli Polyclinic prayed at the Vatican for the health of Pope Francis, who has been in the hospital for two weeks. Instead of the planned audience, a Mass was held at St. Peter's Basilica.

The eyes of the Catholic world are focused on Agostino Gemelli Hospital in Rome, where Pope Francis remains hospitalized for a number of health issues. Here's what to know about the Pope's health situation—and what experts think it says about the risks of respiratory infections in older people.