( Reuters)-U.S. drugmaker Merck Co Inc said on Monday the European Union's drug regulator has initiated a real-time review of its experimental COVID-19 antiviral drug for adults. Under the procedure, also known as a" rolling review", the European Medicines Agency( EMA) would assess data as soon as it becomes available, instead of waiting for a formal application when all required information has been gathered. While vaccines are the main weapons against COVID-19, Merck's experimental pill molnup