Researchers claim breakthrough in HIV, hep C with DNA vaccine

Australian researchers have claimed to have made a significant breakthrough in tackling HIV and hepatitis C, using a new type of DNA vaccine which protects against the viruses and could possibly provide a cure in five years, according to a media report today.
Eric Gowans of the Adelaide University said the vaccine has already seen positive results in animals, with human trials to start next year, an ABC report said.
"DNA vaccines in general have enormous potential, but have not worked very well in large animals and in patients," Gowans said.
"They work very nicely in mice and we have developed a protocol and a technique that simplifies the whole process and makes a DNA vaccine very much more effective in large animals," he said, and added that he has found a way to stimulate the body's immune system response which helps deliver the vaccine.

DNA vaccines usually target muscles, but his technique injects DNA into the skin, he said.
"Because we want to improve the efficacy of the DNA vaccination, we target the skin because the skin has a much greater proportion of white blood cells, which are important for the kind of immunity that we are trying to impart," he said.

Those white blood cells are known as dendritic cells and play a key role during infection and vaccination.
The DNA vaccine stimulates the body's immune response and combines with the white blood cells to kill HIV or hepatitis C cells.
"What we need to do is to target that small population of white blood cells, which circulate generally in the body, and unless the vaccine targets those cells, the vaccine isn't effective and isn't efficient in any way," Gowans said.

"So we've developed a strategy that targets these white blood cells in an indirect manner; we generate a little inflammation and that attracts all these white blood cells to that site of vaccination" he said.
Gowans said other researchers have used skin to deliver the vaccine, but not to target white blood cells in this way.
"We kill the cells that the vaccine is targeted to, and then those dead cells are highly inflammatory and they attract more of these white blood cells, so that is the difference," he said.
While the vaccine is currently designed to treat patients who already have hepatitis C, Gowans said, it is likely, it could be used as a preventative vaccine for hepatitis C and HIV in the next five years.

"It's a significant advance; the strategy is novel, because we have the patent and it's been examined," he said.
"I don't want to be too optimistic, but I think when we do the clinical trial next year, I think we can then begin to work out how best to take it forward from there.