Brief shocks may deliver AIDS vaccines better

Brief electric shocks may help the body better respond to certain kinds of experimental AIDS vaccines, U.S. researchers said Oct. 22.

They used a device that looks like a handgun to inject vaccine along with three brief electrical pulses to open up cell membranes so that the vaccine can get inside.

Sandhya Vasan of the Aaron Diamond AIDS Research Center in New York said the technique, called electroporation, may be particularly useful in delivering DNA vaccines, which use an infectious agent's own genetic material to elicit an immune response.

"With a brief pulse of electricity, our cell membrane temporarily opens up and allows a lot more of the DNA to get inside. The reason why DNA vaccines by themselves don't trigger a powerful immune response is because most of it [DNA] does not get inside our cells," Vasan told Reuters in an interview.

In their study, Vasan and her colleagues used a relatively weak experimental DNA vaccine designed in 2001 using four genes from an AIDS virus circulating in China.

When the vaccine was given by injection alone, 25 percent of participants developed any immune response. But in its latest trial in 2007-09 when the same vaccine was delivered using electroporation, the immune response appeared far stronger, Vasan told a meeting of AIDS vaccine researchers in Paris.

"This is the first clinical trial of electroporation in healthy volunteers for a preventative vaccine. It can be applied to many diseases, many vaccines, not just for HIV," Vasan said. Her group plans to go into Phase 2 trial delivering another, stronger DNA vaccine through electroporation.