The US Food and Drug Administration has approved Arexvy, the first vaccine to combat severe respiratory syncytial virus (RSV). The vaccine, developed by GlaxoSmithKline, is 82 percent effective in preventing lower respiratory tract illness caused by RSV in adults aged 60 and over, according to trial data, and 94% effective in those with at least one underlying medical condition. RSV is the leading cause of hospitalizations among newborns and younger children and also affects older adults, causing over 177,000 hospitalizations and 14,000 deaths each year. The FDA’s approval reflects the agency’s commitment to developing safe and effective vaccines for use in the US. Sanofi and Pfizer are working on related RSV vaccines to prevent the disease in pregnant women, older adults, and infants and toddlers.