Patients afraid of flu shots, young or old, may soon be spared the nervousness of another prick as Korean researchers work on a new vaccine that is simply placed under the tongue.

An international team of researchers from Korea, Japan and France, led by Dr. Mi-Na Kweon of the International Vaccine Institute in Seoul, reported their findings in Monday’s online edition of Proceedings of the National Academy of Sciences.

The authors wrote that the flu vaccine, whether a live or inactivated flu virus, worked in mice and that succeeding in developing it for humans could mean a more comfortable alternative to both the painful prick and the inhaled vaccine in nasal sprays, the Associated Press reports.

Preliminary testing conducted on mice showed that, after receiving two doses of flu vaccine under the tongue, the animals’ immune system was better able to fight off a potentially deadly dose of flu.

The drops of liquid influenza vaccine placed under the tongue enabled the vaccine to reach mucus membranes directly, prompting a response both in mucus tissues throughout the body as well as in the immune system itself, the researchers said.

Kweon added that in mouse studies, there is a theoretical possibility of a nasal spray reaching the central nervous system and this would not happen with the under-the-tongue vaccine, the AP reports. This occurs rarely but it is nevertheless a potentially serious complication.

Kweon likewise reported that, to make the vaccine even more appealing, it can be flavored.

“Aside from its convenience, sublingual vaccination appears to disseminate immunity to a broader range of organs than the classical routes of injecting or ingesting vaccines,” Dr. Cecil Czerkinsky, deputy director-general for laboratory science at the Institute, said in a statement.

“If these findings are replicated in humans, they could pave the way for the development of a new generation of vaccines that could be used for mass vaccination against respiratory infections, including the pandemic avian-human influenza viruses,” he continued.

Should the “sublingual” vaccine be developed, this could make the immunization of large numbers of people more facile, without the need to have specialists administer injections.