The hope was that exposure to the genes would prompt an immune responsein the body so that cells containing HIV virus would be recognised and destroyed.
"The record, in short, is one of careful analysis at every stage, a continued commitment to research and prompt and decisive action inresponse to clinical-study results, " the scientists say.
China declared its support for steps to stop illicit trafficking of nuclear material in what correspondents describe as an uncharacteristically promptresponse to a US initiative.
Acpo is now waiting to hear from police forces in England and Wales about any cases which may need revisiting - a spokesman said it expected a "prompt response".