Australian scientists are devising a vaccine which can be swallowed in food instead of being injected.
Clinical trials led by Dr Barry Marshall have identified certain strains of a stomach bacteria as the basis for edible vaccines.
The results mean Dr Marshall and his team will apply for approval to trial their first edible vaccine containing a bug with a flu vaccine attached to it within a year.
"The next step is to submit this data with an application to government bodies like the TGA (Therapeutic Goods Administration) and FDA (Food and Drug Administration) in the US, perhaps, for the next study which would be to put a vaccine into bacteria we have chosen to show we can vaccinate somebody," Dr Marshall said.
"The next trial will not be a giant study but it may be 30-100 participants."
For the recent trials, Dr Marshall's team of 15 scientists at his biotech company Ondek carried out tests on a group of 30 people in Perth.
They injected five strains of the bacteria Helicobacter pylori, a stomach bug - into five groups of six participants to find out if they would cause any side-effects.
The bugs were collected from elderly people in Sweden who had carried the bugs all their lives but never showed any symptoms.
The bugs easily infected the trial participants, who suffered none or only minor side-effects such as occasional stomach upsets.
Three of the bug strains lasted longer than three months, while the other two disappeared in the same period.
The results suggested the bugs were safe for scientists to attach vaccines to for delivery through the wall of the stomach instead of via a syringe.
"One of the things we might be able to do with this vaccine is vaccinate people for the long term," Dr Marshall said.
"The (bacterium) strain will sit there and vaccinate you for weeks or months.
"Then there are others which colonise you temporarily which would be good for things like flu vaccines."
In the trials, the bugs were given to the participants in the form of a chicken broth.
For the next trials, the scientists plan to give participants one dose of the edible vaccine, possibly in the form of a yogurt which Dr Marshall believes is ideal for people to eat as a vaccine.
Dr Marshall, who won a Nobel Prize in 2005 for discovering Helicobacter caused stomach ulcers, said there was huge potential for edible vaccines.
They would be an easy way of providing booster vaccines to baby boomers as well as others to fight off hepatitis B, malaria and swine flu.
"A lot of baby boomers haven't had vaccines since they were kids and they are wearing off and they can develop things like whooping cough and chicken pox," Dr Marshall said.
"We could have different strength vaccines for different purposes.
"Some could be boosters while others could be life-saving vaccines."