Viral replication: Symptoms start by the fifth day after infection for most people, and they include fever, cough, sore throat, fatigue, aches, pains, gastrointestinal issues, and loss of smell or taste. Taison Bell, a pulmonary and critical care physician at the University of Virginia, says that when symptoms arise, this change signals a person is at “peak infectivity,” which means they are shedding lots of virus particles into the air, putting nearby people at risk.

This timing has big implications for the president and those around him, Bell says: “The most famous person in the world right now has COVID-19, and one could assume, based on the time line, that he could have been infectious during the presidential debate.” The televised argument with challenger Joe Biden took place last Tuesday, and Trump began showing symptoms on the following Thursday. “He is still infectious now and was when he took his joyride,” says Bell, referring to short trip Trump took in a car with Secret Service agents on Sunday. The vehicle traveled around and just outside the Walter Reed National Military Medical Center, where he was being treated.

At this early stage of the disease, most people do not receive aggressive treatment, but Trump was given two experimental drugs: the antiviral medication remdesivir and an infusion of monoclonal antibodies.