PowderMed Ltd has said that an experimental flu vaccine that blasts tiny particles into the skin instead of using a needle appears to be safe in people.
The British-based company said it would move into bigger tests of its vaccine, which uses DNA from the flu virus to stimulate immunity.
Writing in the journal Vaccine, PowderMed scientists said the vaccine stimulated an immune response in all 36 volunteers.
Based on these results, PowderMed will start phase II studies using both annual and bird flu strains later this year. A finished product would still be years away.
"Recent years have seen a number of new influenza vaccine approaches tested in animal model systems and in the clinic," said Dr. Hansi Dean, formerly with PowderMed and now with the International AIDS Vaccine Initiative.
"However, this study is the first successful demonstration of immunogenicity of an influenza DNA vaccine in humans."
"DNA vaccines have the potential to significantly limit the burden of disease," added Dr. Clive Dix, chief executive officer of PowderMed.
"The advantage of a DNA-based approach is that the vaccines can be manufactured very rapidly and in large quantities, while yielding an efficacious immune response at low doses."
PowderMed's vaccine is produced by copying a gene from the virus - either the circulating influenza virus or the H5N1 avian flu virus - and enclosing it in tiny gold particles.
It is delivered using an injector powered by concentrated helium gas, which pushes the particles into the skin.
The privately held firm is counting on some studies that suggest vaccines delivered right under the skin may produce better immunity than injected vaccines.
And the company said the vaccine is stable and does not need to be refrigerated, or even administered by medical professionals, as are current vaccines.