It’s official. An experiment run out of Thailand has come out with a moderately successful HIV vaccine that prevented infection in 31 percent of patients. It was the world’s largest AIDS vaccine trial that included more than 16,000 Thai volunteers. My question is, did they also volunteer to be infected? How did this work exactly?
The study actually tested the vaccine in HIV-negative Thai men and women 18 to 30 at average risk of becoming infected. Half received the vaccine, the others dummy shots. Then the “humans were released” out into the HIV (computer model shown here) rampant country I guess. (I still don’t know why, if you’re careful and logical, you should get infected at all. Just don’t sleep around. That’s it. Get married to someone HIV negative, settle down, stay faithful, and raise a family. But anyway…)
“It’s the first evidence that we could have a safe and effective preventive vaccine,” said Colonel Jerome Kim, who helped lead the study for the U.S. Army. However, the director of the institute cosponsoring the study, Dr. Anthony Fauci, cautioned that this is “not the end of the road.”
Now that they’ve got something to work with – a 31% success rate – they can continue to work on improving its effectiveness by doing a bit of some biological tweaking. This is what they’re excited about, because this they can do. Before now, it was just stabs in the dark. Now with a stepping stone, it may only be a matter of time before AIDS goes the way of Polio. I speak optimistically, so don’t take my word for it. It’s just a hope.
But even if they can improve it only slightly, a marginally helpful vaccine could still have a huge impact. 2 million died of AIDS in 2007, with a similar number passing in 2008, it is estimated. 31% of 2 million is 620,000. Don’t forget.
“Today marks an historic milestone,” said Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition.
The Thailand Ministry of Public Health conducted the study, and this is how they did it: They tested a two-vaccine combo in a what is called a “prime-boost” approach. The first vaccine primes the immune system to recognize and attack HIV, and the second boosts the immune system to continue fighting.
The vaccine uses an altered bird virus called canarypox that can’t infect humans, and pumps it with three HIV genes so the body can recognize HIV before it hits. The other part of the vaccine then introduces a protein present in the wall of HIV to get the body to attack that as well. Since the vaccine is not HIV itself, it comes with no risk of causing it.
Neither of the vaccines worked at all when used on their own, but together seems to have produced something. “I really didn’t have high hopes at all that we would see a positive result,” Fauci said of the human trials.
The results, though, were as follows: New infections occurred in 51 of the 8,197 given vaccine and in 74 of the 8,198 who received dummy shots. That worked out to a 31 percent lower risk of infection for ones who got the vaccine.
Could it be a fluke? We won’t know until other studies are conducted.