According to the results of a phase three trial released by GSK on Wednesday, GSK’s GSK +1.59% vaccine against respiratory syncytial viruses for older adults could protect them from disease for up to two RSV seasons. The company stated in a press release that similar efficacy over two seasons was observed in adults with underlying conditions and advanced age. In May , the U.S. Food and Drug Administration approvedthe Arexvy vaccine for RSV prevention in older adults. RSV is an extremely contagious virus which causes infections of the lungs and respiratory tract. GSK’s ADR has fallen by 1.5% year-to-date, while S&P 500 has risen 14%.