I think Scott Hensley, for NPR's Health Blog, has it just about right, here -- this is simply an encouraging first step -- not much more, given the discouraging brick wall Merck (and many others before it) recently struck, on the path of AIDS-vaccine research. Do go read all of the NPR piece, but here is a snippet:
. . . .While encouraging, the modest positive results raise questions, too. The vaccine regimen tested, designated RV144, was actually two vaccines -- one to prime the immune system to attack HIV and the other to boost the response. Volunteers in the study got multiple shots of vaccine or placebo over several months. Previous tests of the vaccines given alone failed. . . .
One reason for vaccine skepticism was the finding two years ago that a Merck vaccine raised the risk of HIV infection rather than lowered it. The project was canceled and vaccine researchers fell into a funk. . . .
Keep your fingers crossed that this leads to more encouraging results.
However, one disappointing result from the current Thai combo study was that of those who were treated with study meds, yet did still contract an active form of the HIV virus, after vaccination -- the treated population's viral loads were no lower than the placebo population's. That is a particularly confounding development. Still, let us keep a positive thought, for creative developments, based upon learnings from the Thai combo study. This is about as complicated a task as biological science can offer.