The F.D.A. authorized AstraZeneca’s treatment to be given outside a health care setting, although it will still need a prescription.

The FDA is clearing the way for an at-home flu vaccines. A self-administered version of pharmaceutical giant AstraZeneca’s FluMist was approved Friday by regulators for household administration in patients ages 2 to 49. The spray, which has been available via a doctor's visit since 2003, is roughly as as effective as injected vaccines.

The Food and Drug Administration on Friday approved the first at-home flu vaccine, a nasal spray that consumers with a prescription will be able to order online starting next year. Health experts say the convenience of the spray — FluMist — could lead to increased flu vaccination rates.