On Aug. 3, 2021, Moderna announced that the U.S. Food and Drug Administration (FDA) had granted Fast Track designation for mRNA-1345, its investigational single-dose mRNA vaccine against respiratory syncytial virus (RSV) in adults older than 60 years of age.

Respiratory syncytial virus is a common respiratory virus that generally causes cold-like symptoms. RSV infections occur primarily during fall, winter, and spring. Most people recover in a week or two, but RSV can be serious, especially for infants and older adults.