COVID-19 booster shots could soon be given as nasal sprays.

Approximately a dozen different COVID-19 nasal vaccines are currently in clinical trials or pre-clinical trials.

They work by creating immune resistance in a person's nose and throat, stopping the virus from spreading right as it enters their body.

"That's very important for preventing infection and transmission, which is not currently able to do with the shots," said Akiko Iwasaki, a researcher at Yale who is working on a nasal COVID vaccine.

Nasal vaccines are not new. They are used to prevent flu infections. However, they aren't always as effective as the shots.

Iwasaki says that's because flu mist relies on infectious viral particles that people develop antibodies against.

She said that wouldn't be the case with the COVID nasal vaccine.

"Nasal vaccines are, I think, very promising and key to kind of containing the spread of the virus and preventing diseases, including long COVID because of the fact that it works at the first stage of infection," she said.

Once approved, the hope is for the vaccines to be distributed at pharmacies or even by a person at home.