A pill to treat Covid-19

Antivirals are essential treatments for treating viral infections such as hepatitis C and HIV. One of the best known is Tamiflu; the widely prescribed pill can shorten the duration of influenza and reduce the risk of hospitalization, if someone takes it early in the course of infection. Scientists are working toward a similar treatment for Covid-19, reports Kaiser Health News’ JoNel Alecia. Different medications work to fight viruses in different ways. Antivirals can be engineered to boost the immune system to fight infection, block receptors so viruses can't enter healthy cells, or lower the amount of active virus in the body. One antiviral known as remdesivir has already been approved by the US Food and Drug Administration to treat Covid-19. But use of it is limited because it has to be administered by IV and wasn’t intended for early, widespread use. Currently three promising Covid antivirals -- all pills -- are being tested in clinical trials, with results expected as soon as late fall or winter. The top contender is a medication from Merck and Ridgeback Biotherapeutics called molnupiravir. Pfizer is developing another potential treatment, and still another is in the works from Roche and Atea Pharmaceuticals. All three work by interfering with the virus' ability to replicate in human cells. In the case of molnupiravir, the enzyme that copies the viral genetic material is forced to make so many mistakes that the virus can't reproduce. That, in turn, reduces the patient's viral load, shortening infection time and potentially preventing the intense immune reaction that can follow and lead to severe disease.