In this week's Science, an article showing protection in macaques against an analogue of HIV is creating all sorts of buzz in the media (Dear Daily Mail...it is not a vaccine).
One of the hurdles to developing drugs against HIV has been making sure that patients are actually sticking to the drug regime. The short half life of these treatments often mean (at least) daily doses. There's a lot of variability in how well patients stay on schedule, resulting in some people not getting enough drug to fight off the virus.
Researchers decided to investigate a slow release drug to see if it could actually reduce the doses needed, improving the ability of the drug to work. To do this, they used a type of drug called an integrase inhibitor, packaged as slow-releasing nanosuspension (thanks for the catch, Sparrowgrass!). One of the reasons HIV is so nasty is that it can insert itself into our genomes with its integrase, making it even more difficult to eliminate. Once in, it can be passed on as the cell divides, as well as take over the cellular machinery to make more viruses.
To test their treatment, they injected it into macaques, and then challenged them rectally with low doses of SHIV (mix of simian and human virus). All the treated monkeys remained safe from infection, while all the control monkeys contracted SHIV. In a sister study done by the CDC, protection was also seen with a vaginal challenge of virus. Preliminary tests were done in humans, which showed that the drug is safe, and can last for weeks before being metabolized.
Of course, it still needs to be shown to work against HIV in humans, although the fact that this is a primate study makes it very promising. If it works in humans, this drug could be given as a shot to people once every couple months or more, making it much easier for people to protect themselves from infection.