AIIMS chief Dr Randeep Guleria told NDTV that COVID-19 treatment strategies keep evolving. Remdesivir is an antiviral drug which was basically developed for management of Ebola, he said. "Initial studies showed it is of no use but subsequent studies showed that Remdesivir was used on people who have severe to moderate disease... There was no mortality benefit," he said. "As of now, we don't have a good antiviral drug," the AIIMS chief said at NDTV Solutions Summit. He also explained the differences with steroids, what is dexamethasone, ivermectin and Fabiflu and at what stages are these drugs given to Covid patients.