Researchers say delivering the flu vaccine under the tongue may not just scrap the need for needles, it could also provide more effective protection.
Needles may put some people off getting their flu vaccine
Experiments on mice showed that delivering the vaccine "sublingually" protected the rodents against flu without any obvious side-effects.
It is thought this method may prove more effective than jabs as it protects the area where the virus first enters.
The study appears in the Proceedings of the National Academy of Sciences.
The international team, comprising researchers from Korea, Japan and France, used a lethal dose of flu on the mice to determine how well their technique worked.
They found that two doses of either live or inactivated flu virus conferred protection.
Up the nose
Mucosal delivery, where the vaccine is administered in either the mouth or nose, is seen as the "holy grail" by some health professionals - in part because it makes it so much easier to deliver.
For one it would cater to those who do not like needles, but more importantly it would make it possible to deliver immunisations to large numbers of people - perhaps in remote areas - without the need for specialists to administer injections.
Jabs can also carry side-effects, including painful inflammation.
Work has been done on a vaccine which is administered via the nose, but this can allow the virus to travel into the central nervous system, a rare but potentially serious complication.
This did not appear to happen when the researchers gave the vaccine to the mice under their tongues.
It is also a tried and tested technique for other treatments, the researchers said, and "its safety is now well established".
They continued: "Our findings strongly suggest that sublingual delivery could be a more effective avenue than traditional approaches for vaccinating against both seasonal and pandemic flu".
But Professor Karl Nicholson, professor of infectious diseases at the University of Leicester, said research on animals in this area did not always translate well when carried out on humans.
"It would be great to develop a vaccine which could be administered in this way. To eliminate the need for needles would be a major advantage - but it is very early days indeed."