The FDA has approved a nasal spray flu vaccine for home use. Here's how it works, and when it will be available.

A no-frills nasal spray could potentially provide effective protection against "deadly respiratory infections" and Covid-19, tests on mice suggest. In findings published in the journal Advanced Materials,

A nurse gives a shot of Covid vaccine at a community health center at Nantong, China, December 9, 2022. A new spray is said to offer broad-spectrum protection against various respiratory infections, including Covid-19, influenza, common cold viruses, and pneumonia-causing bacteria. Chinatopix via AP

Most respiratory viruses, like the flu and COVID-19, enter the body through the nose. When an infected person exhales, sneezes, coughs, or even laughs, they release droplets containing the virus, which others can inhale. These pathogens attach to the nasal lining, replicate, and are further spread.

The Food and Drug Administration (FDA) has approved the first nasal spray flu vaccine which can be administered by the patient or a caregiver. FluMist, produced by European pharmaceutical company and Covid vaccine-maker AstraZeneca, was announced last week and can be used by adults aged 49 and under.

FluMist is the only nasal flu vaccine, but it is not new. The FDA approved it in 2003 for people 5 to 49 years old before expanding eligibility in 2007 to children as young as 2 years old — requiring in both instances that it be administered by a vaccine provider.

If this flu-busting nasal spray lives up to its promise, it will be a blockbuster. Scientists at Harvard Medical School have developed a simple nasal spray, made of harmless ingredients, that they reckon can protect us against flu,

Brigham researchers have developed a nasal spray called PCANS that blocks a wide range of respiratory infections by trapping and neutralizing pathogens in the nose. In lab and animal tests, the spray effectively prevented infection,