Steroids such as blunt infection of dexamethasone within the body. Researchers believe that some individuals with high cases of COVID-19 have hazardously high levels of inflammation as part of an overactive immune response to the virus and that calming that down with an anti-inflammatory like dexamethasone could help ease their symptoms.  This is also why people should not take this drug to try to prevent COVID-19: it affects the immune system and may make it more difficult to fight off the virus. Scientists say the treatment works when someone’s illness is serious enough to cause infection more harmful than the virus itself.  Dexamethasone is the first drug that has been shown to improve survival in COVID-19, “said in a statement Peter Horby, professor of emerging infectious diseases at the University of Oxford and a lead investigator on the trial. In those patients who are ill enough to need oxygen therapy, the survival advantage is obvious and massive.