Needle-free vaccines that would be spread on the skin might take the "ouch" out of getting vaccinated, research on mice suggests. Scientists from Iomai Corp. in Washington, D.C., shaved a patch of hair off mice. They then applied a solution containing proteins that are ingredients of vaccines against either diphtheria or tetanus, mixed with a dose of the toxin produced by cholera bacteria. This toxin revs up the immune system, boosting the response against whatever accompanies it.
The scientists report today in Nature that the mice built up antibodies in their blood against diphtheria and tetanus, just as they would have with injected vaccines. The cholera toxin was not harmful. Apparently, the skin vaccine is taken up by immune system cells in the skin, which then alert the rest of the immune system. The researchers hope to start the first human trials within two months.