On Wednesday Eastern Time, Moderna, a US vaccine manufacturer, fell more than 11% in stock price due to the sharply decreased effectiveness of the company's respiratory syncytial virus (RSV) vaccine, which lags far behind competitors Pfizer and GlaxoSmithKline. Data released by the US Centers for Disease Control and Prevention (CDC) on the same day showed that more than a year after receiving the Moderna RSV vaccine mRESVIA, the effectiveness against RSV-related lower respiratory tract diseases was 50%. In comparison, Pfizer's RSV vaccine Abrysvo had an effectiveness of 78% in the second year, and GlaxoSmithKline's RSV vaccine Arexvy had an effectiveness of 78% in the second RSV season. This result may further raise doubts about the prospect of Moderna's vaccine and put further pressure on the company's stock price.