If the vaccine passes further safety trials, scientists believe it could provide a revolutionary new weapon against obesity.
Currently the only non-dieting options for controlling weight are surgery and strong drugs, both of which can have serious side effects.
More than a quarter of adults in Scotland are obese, according to official figures from last October.
Adult obesity in those aged 16-64 rose from 17 per cent in 1995 to 27 per cent in 2010. If Scottish obesity follows the same trend as figures in the United States, the rate could reach 40 per cent by 2030.
The new experimental vaccine works by stimulating the immune system to attack a hormone that promotes slow metabolism and weight gain.
In tests, obese mice fed a high fat diet saw a 10 per cent drop in body weight four days after receiving the jab.
Two slightly different versions of the vaccine were studied. Both produced a sustained 10 per cent reduction in body weight after booster injections were administered after three weeks. The slimming effect was not seen in a matched group of 10 untreated mice.
Lead researcher Dr Keith Haffer, from the US company Braasch Biotech in South Dakota, said: “This study demonstrates the possibility of treating obesity with vaccination.
“Although further studies are necessary to discover the long-term implications of these vaccines, treatment of human obesity with vaccination could provide physicians with a drug and surgical-free option against the weight epidemic.”
Research published last year in the Lancet medical journal showed that almost half of all British men could be obese within 20 years.
Being obese is defined as having a Body Mass Index – a measurement relating height and weight – of 30 or more.
The percentage of overweight women in Scotland stands at 34 per cent while those classed as obese rose from 26 per cent to 29 per cent between 2003-2010.
The new vaccine uses a modified form of somatostatin, a peptide protein molecule that functions as a hormone.
In both mice and humans somatostatin suppresses growth hormones that boost metabolism and cause weight loss.
The vaccine “flags up” somatostatin so that it is seen as a potential threat by the immune system. It causes the body to generate antibodies that neutralise the peptide.
Reporting their findings in the Journal of Animal Science and Biotechnology, the scientists wrote: “The vaccination effects did not significantly reduce cumulative food consumption and was confirmed by residual anti-somatostatin antibodies in mouse plasma at the study’s end.”
Further research will examine the effects in obese pigs and dogs before moving the research onto trials involving human patients.