By Bethany Wales The FDA has expanded its approval of a GSK vaccine that prevents respiratory syncytial virus(RSV) to affect younger adults, in a move the company hopes will prevent thousands of hospitalisations each year. The vaccine, Arexvy, is produced by British pharmaceutical company GSK and is currently only available for adults aged 60 years of older in the US. According to the firm’s research, there are about 13 million people between the ages of 50 and 59 in the US with underlying conditions that place them at higher risk of RSV disease, including congestive heart disease, asthma, dia…