Title is misleading. To me, the headline "AIDS vaccine in final testing" implies that they are undergoing their final testing to verify that it does indeed prevent people from contracting HIV. That is not what it means. Rather, it means that they are in the final rounds to verify that the vaccine is safe, before they start human trials.
A more accurate title, to my ears, would be "HIV vaccine almost ready for human trials."
There are 3 major phases in clinically testing a drug's safety and efficacy before it's brought to market, and it seems like they're close to starting the first one.
For all those interested in the 3 phases, here they are:
Phase 1: Small number of healthy volunteers to assess drug safety, toxicity, and pharmacokinetics.
Phase 2: Small number of patients with the disease of interest to test drug efficacy.
Phase 3: Large number of patients with the disease of interest to test effects of new treatment in comparison to those of existing treatments. This is where you see double-blind studies, etc.
Personally, this isn't terribly noteworthy. They've merely devised a new theory that's shown to be effective using animal models, and are still quite a ways away from seeing if similar results will occur with human testing. Of course, I do hope they see good results.
> Phase 2: Small number of patients with the disease of interest to test drug efficacy.
> Phase 3: Large number of patients with the disease of interest to test effects of new treatment in comparison to those of existing treatments.
I'm not sure phase 2 and 3 make sense for a vaccine though. Vaccines are only useful for healthy people. I guess the testing is done on healthy animals which are then transmitted the HIV virus, unless some people would accept to go through that kind of testing, not very likely but I'm no specialist so I may be wrong.
As explained elsewhere, you give the vaccine and a placebo to an at-risk. Than you follow up X years later to check infection rates. Everything's double blind, so there's nothing statistically different about the two populations other than the vaccine vs. placebo.
Super-sucks to be in the placebo group on this one if the vaccine really works.
It reminds me of a study done in IIRC South Africa (although it's been a year or more since I heard of this so it could be anywhere in Africa really) where they circumcised a group of males to see the effect on HIV contraction and it was so great (due to HIV's severely limited lifetime outside the body compared to over viruses and bacteria's) that they ended up circumcising the control group.
Hopefully if this study goes well then they'll do the same. I'd sense a massive lawsuit if scientists caught major wind of a guaranteed vaccine and sat on it for the sake of evidence for 5 years and let X-many people get HIV.
> I'd sense a massive lawsuit if scientists caught major wind of a guaranteed vaccine and sat on it for the sake of evidence for 5 years and let X-many people get HIV.
This is wrong on so many levels.
First, until you conduct the trials have the evidence there is no guarantee that (a) the vaccine works and (b) that it isn't harmful itself. The idea of a guaranteed vaccine that hasn't been through trials is nonsense as trials are an integral part of such a guarantee.
Second, you can't sue someone for with holding such a drug unless you have some sort of basis in law to have that drug - basically a contract between you and the company. As the drug companies can't legally sell a drug that hasn't passed testing no such contracts exist. While I'm sure you'd like to exert some sort of moral right to the drug (and I'd kind of agree with you), a legal right which could form the basis of a law suit simply isn't there.
Third, why would a company sit on a vaccine for AIDS? Yes a majority of those at risk are in the third world and have no money but there is a market of hundreds of millions who could afford and would pay for a vaccine in the wealthy developed world. It simply makes no sense to suggest that they would do anything of the sort.
> I'd sense a massive lawsuit if scientists caught major wind of a guaranteed vaccine and sat on it for the sake of evidence for 5 years and let X-many people get HIV.
Considering that all prior HIV vaccine attempts failed completely, sitting on it till they know for sure is exactly what they should do.
And, BTW all those vaccines also came with press releases that touted how great it was, and how sure they were that this time they got it.
Based on past history I would give this vaccine less then 10% chance of actually working.
You seem to be focused on success, but realistically the vast majority of pharmaceutical trials fail.
I'd sense a massive lawsuit if scientists caught major wind of a guaranteed vaccine and sat on it
That's why you do this phase in poor countries. Duh.
For instance, contraceptives were widely tested in Puerto Rico in the 50's before being put on the national market in the 60's. They weren't initially sold in Puerto Rico, though, because there wasn't enough money in it yet. [Caveat: I don't know this from personal experience - it's common knowledge in Puerto Rico, but then it's common knowledge here in Indiana that Barack Obama is a foreign-born Muslim, so ... take it all with a grain of salt.]
It is well documented, this a good documentary about it [1]
And it was not the worst case. The US government infected people intentionally with syphilis and gonorrhea in Guatemala during the 40's to research about STD [2], last week the U.S. goverment was sued over those syphilis tests [3].
Note that in this case of circumcision the possible negative effects are well known, but a vaccine might have complications in X years that would not be worth the decreased contraction of AIDS. In hypothetical example, perhaps it increases the chances and severity of heart attacks by some ridiculous percentage.
In general, with medicine, it sucks to be on the wrong side of an experiment, but it can be difficult to know which side that is.
It's tricky: there is often monitoring of interim results for exactly this reason, but there are some good theoretical reasons to think that halting a trial on the basis of good interim outcomes in the experimental group could bias the results.
That was South Africa (I'm here). That wasn't a study on circumcision, that was nothing more than a statistical correlation, and one without any established causal relationship to support the 'prevents HIV' claim. There are many other factors to explain the correlation - cultural, economic and demographic.
Circumcision is still practiced as a coming-of-age rite here by many.
That was South Africa (I'm here). That wasn't a study on circumcision, that was nothing more than a statistical correlation...
Look again. There have been multiple studies. The ones most often cited were in Uganda and Kenya, and they were real studies. (If only single-blind for obvious reasons.) See http://www.niaid.nih.gov/news/qa/pages/amc12_qa.aspx for more details.
Your criticism is accurate for the South African studies. But we have better data today.
Getting a false positive result because you screwed your significance test because you decided to stop early? When you release it to the public, people think they're protected, so many more people than X die.
For vaccines you test against a population and compare disease rates between the people who received the vaccine and those that did not. In situations like this I would guess that they will select a high-risk group and then compare infection rates over time between the two groups to see if the vaccine has any effect.
This is not true. There is no biological reason why a vaccine wouldn't work on an infected individual.
What you say is a myth, mostly as a result of most vaccines being about accute infections, like smallpox. In those cases, there is no real idea in administering a vaccine to a person who is already ill, because by the time the immune system is ready with its strong specific answer (which is a matter of days), the patient would be either dead or cured by "natural" response to the virus.
There are already vaccines targeting (successfully) diseases with a long incubation period. Examples for this are tetanus and rabies. You get your vaccine after being bitten (by a rat for example), and you are OK.
In the case of rabies treatment, if the patient has not received the rabies pre-exposure vaccination then they must receive a dose of immunoglobulin (antibodies against the rabies virus) in addition to the rabies vaccine. Without it, the patient would die before their immune system would be ready to fight the virus. Receiving the dose of immunoglobulin gives the immune system enough time to start producing its own antibodies.
For this reason, travellers to countries where immunoglobulin may not be available are often advised to get the rabies pre-exposure vaccination before they go.
Don't know much about drugs and trials so I am speaking out of my ass but I'd assume if the numbers were large enough, you don't actually infect the patients.
I would expect you could compare the natural rate of infection in the target group vs the control group after many years taking into account the historical/expected rate of infection in a random sampling of the population involved.
A more accurate title, to my ears, would be "HIV vaccine almost ready for human trials."