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AIDS Vaccine Is Partially Successful
ifchairscouldtalk writes "A Phase III 'RV 144' study in Thailand succeeded in reducing HIV infection rate in trial with 31.2% effectiveness. The study was conducted by the Thailand Ministry of Public Health and used strains of HIV common in Thailand. It is not clear whether the vaccine, which combines AIDSVAX with Aventis Pasteur ALVAC-HIV canarypox vector, known as 'vCP1521,' would work against other strains in the United States, Africa or elsewhere. Strangely, the vaccine had no effect on levels of HIV in the blood of those who did become infected, providing 'one of the most important and intriguing findings' of the trial, according to Dr Fauci, director of the National Institute of Allergy and Infectious Diseases, which is one of the trial's sponsors."
I'm not normally a stickler for these, but AIDS is a syndrome, HIV is the virus that causes it. The vaccine can prevent you from acquiring HIV and thence from developing AIDS. It's not a cure, it's a preventative measure.
I was promised flying cars...Why are there no flying cars?
Cool! Hopefully by the time I become sexually active it will have improved much more!
You just got troll'd!
You should go teach the doctors and scientists what they are doing wrong.
...but their conclusions.
How in the hell could you ever do a controlled experiment like this on people if you dont control their exposure to the infection causing material? The only way you can determind improvements of real thing over placebo is if you intentionally expose the test subjects to the virus...which would be a death sentence.
Their results could mean that the group recieving the test vaccine came into contact with the virus 31.2% less.
1331461 is only semiprime *sigh* Alas - I am just short of 1337.
How is that news for nerds ?
None of us will ever get laid, so that's not stuff that matters...
</cliché>
I have discovered a truly marvelous proof of killer sig, which this margin is too narrow to contain.
While this is excellent news, and intriguing scientifically, an effectiveness of 31.8% is practically useless in vaccinating a population. Typically you need at least 70% of your population (varies based on virus) vaccinated before you start to see the effects of herd immunity. Even if they vaccinated everyone in Thailand, you wouldn't get this effect.
Furthermore, the low effectiveness is actually a liability; the end result could be mutations in the HIV virus that make it immune to the vaccine. This is part of the reason why the influenza vaccine has limited effectiveness - influenza, like HIV, has a tendency to mutate quickly. If a new strain comes along, like H1N1 for influenza, you're defenseless.
Finally, I think there's a problem with how the vaccine will be perceived. If the vaccine is only 30% effective, I think people will see that as being too risky to even get the shot. There's already (too much IMO) FUD out there against vaccines in general. If you think that you can get influenza from the flu vaccine, there's a strong aversion to taking the HIV vaccine. For a 30% chance at being immune, that's no good. If it were 100%, that would be a totally different story.
The sample sizes were not 74 and 51. The sample size of people vaccinated was "more than 16,000 volunteers". 74 and 51 were just the number of people infected, which is still statistically significant. [to what confidence level, I do not know].
Formerly known as not successful.
I... don't recall the world ever being black and white. I'm pretty sure what you're doing is called "oversimplifying".
I am the lawn!
someone do some analysis on the statistics and tell us all something and get +5
Sure. It's Poisson statistics, so the standard deviation is the square root of the count.
placebo: 74 plus or minus 8.6
vaccine: 51 plus or minus 7.1
The statistical significance of the difference (23) is equal to the standard deviation of the sum (not the difference!) of the counts, so:
difference between placebo and vaccine:
23 (=31%) plus or minus 11
= (2.06 standard deviations)
Assuming they set their criteria for statistical significance at two standard deviations, then they are significant.
http://www.geoffreylandis.com
Fortunately, that gives the the researchers plenty of time...
HA! I just wasted some of your bandwidth with a frivolous sig!
No, they just went to a population where HIV is already relatively common and a large number of people don't usually take adequate precautions against it (i.e. use condoms) and then studied the effects of the vaccine on that population's total infection rate over time. It's not the greatest way to test this (since you have no way to tell if it's just down to random variations in the two population's levels of exposure) but doing it properly (i.e. deliverately exposing people) is pretty unethical to say the least.
Of course, you can also test the vaccine on animal models which are deliberately exposed to HIV so we know there's a good chance it will be effective if the population study then shows these kinds of results to corroborate it.
Ultimately one of the purposes of drug trials is also to look at side-effects. Assuming the side-effects of this vaccine weren't too bad, with that kind of effectiveness rate it would seem this stands a reasonable chance of widespread deployment, in which case it'll be possible to gather more data.
Why is it that on slashdot of all places that should be full of nerds we get idiots that don't grasp basic statistics and people that mod it up? As long as you got a proper control group it's simple to say "If we assume the true probability is the same, how unlikely is it that we get these results?" Of course there's something about the level of confidence - a 99% confidence means there's a 1% your observation is random fluctuations. But the whole "we reject math and logic because the numbers feel to small" sounds like the results of retarded anti-schooling.
Live today, because you never know what tomorrow brings
Not at all. What this shows is that the vaccine likely works for some subset of the population. That doesn't mean it doesn't work at all. Viagra for example only works for about 60% of men but people don't go screaming that it doesn't work.
Bottom line here is that vaccine or no, you should still practice safe sex (afterall, HIV isn't the only bad disease lurking around out there). However, if this thing has a ~30% chance of making you immune to the disease with no other ill effects then it's certainly worth reducing your chances by that much.
Basically, to break it down, your chances of getting aids comes down to 3 factors (4 now with this in place):
a * b * c * d
Where
a = the chance that your partner is infected
b = the chance that you catch the disease during an encounter with an infected partner (having intercourse with an infected person doesn't guarantee infection)
c = the chance that your protection fails (only comes into play if you used protection - otherwise it's 100%)
d = the chance that your vaccine was ineffective (only comes into play if you actually got vaccinated - otherwise this is 100%)
Everything that is scientifically proven to reduce the final result, even if it doesn't go to 0% in the end, is a success in my opinion.
"People who think they know everything are very annoying to those of us who do."-Mark Twain
It would be unethical to expose all participants to HIV. They did the next best thing.
There's nothing wrong with the basic idea of the study design. Of course, they may have fucked it up, but that's a different situation.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
But I thought AIDS was sent by God as a scourge of teh gheys. So God must hate the 68.8% it doesn't work for, then.
Kwisatz Haderach
Sell the spice to CHOAM
This Mahdi took Shaddam's Throne
Their results could mean that the group recieving the test vaccine came into contact with the virus 31.2% less.
No, you don't need to control their exposure. You can study the infection rate for the general population, and provided that your study group isn't unusually different from the general population (say, by being all sexually active gay men), you can expect a similar infection rate over time.
yes, there are potentially statistical deviations that could occur, but the larger the sample group and the more test that occur, the less likely this is. Go take some stats classes if you are curious about the methodology, but if they did the trial correctly your suggested interpretation is very unlikely.
HA! I just wasted some of your bandwidth with a frivolous sig!
I take it you haven't seen this ad.
http://www.craigslist.org/about/best/lax/878989144.html
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Er... they *all* underwent the same sex and infection-control education courses, according to the BBC article. Medical researchers don't throw people to the wolves just for the sake of science... at least, not any reputable ones whose research they expect to be followed up.
And if they had never run the test, the results would have been the same. Please, don't push blame onto others, we have enough of that into modern society. There is plenty of education forced down your throat at every turn about HIV/AIDS, if you don't know about it, it is your fault.
-- Lattyware (www.lattyware.co.uk)
Didn't the article say that one group got a vaccine, and the other got a placebo?
"Col. Jerome H. Kim, a physician who is manager of the armyâ(TM)s H.I.V. vaccine program, said half the 16,402 volunteers were given six doses of two vaccines in 2006 and half were given placebos."
Oh yea, that's what it said.
I don't see anything wrong with the basic kind of study. As I said, they may have fucked it up somehow, such as fucking up the selection of the participants and grouping them.
And why would they want to control against additional groups? They're measuring one thing. How effective is the vaccine. Your proposal to control against other groups are actually separate studies. They can and should be run independently at first. I can totally understand them not wanting to add complexity to a study that already has more than 16,000 participants.
So, I still don't see any valid objection as to why this kind of study won't work or is flawed somehow. In fact, this basic type of study is done all the time.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
Apparently you've never watched old movies. Seriously, color is a recent invention.
Belief? Hope? Preference?The Existential Vortex
The highest-rising infected group is heterosexual women in their 20s.
Look it up.
---
ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
The total working group for this test was around 16,000 people. Only 125 actually became infected with HIV during those 3 years. The infected portion shows about 1/3 more in the placebo group. So yes, the sample is statistically significant, and someone wasted a mod point.
Who is John Cabal?
The existing battery of drugs is enough to put HIV into remission. Your immune system will remain healthy and the virus particles will essentially disappear. But it's somewhere inside you; if you stop taking those drugs, it eventually comes back although you may have to wait.
HIV has long been known to hide somewhere in the body after drugs have eliminated the actual virus particles. They found where recently; it integrates its sequence into the DNA of T-cells, and the promoter at the start of the viral sequence is capped by a repressor protein. Once it comes off its DNA binding site, viral proteins start getting transcribed again.
They actually developed a drug that can kick it off there and make your AIDS come back again.
Last Friday's 20/20 was about a some middle-age guy who bedded middle-age women almost every day and infected at least a dozen of them (proven in court by DNA analysis). He must of have had a very effective virus or technique, because infection usually doesnt happen in just a few times. He got 45 years for knowing recklessness. But this was less than two years of his exploits. There is suggestion it was going on for over 12 years and there are many other victims.
The point is that some demographics think they are "safe" because they arent connected with risky types, i.e. gays, druggies, promiscuous youth. But sex is something people lie the most about, and you can never be sure.
P.S. The show & court trial did examine the issue of whether there could be "victims" if there was consensual relations. That wasnt fully resolved in my mind.
This page and this page indicate that the study was double-blind. If it was, then I do not see how your worry is reasonable. If both groups were unaware of whether they received the treatment or not, then I do not see how one group that happened to be the control group would reliably act differently than the experimental group. Am I missing something? Or are you claiming that once people believe they have the vaccine, that they will have more unprotected sex and thus increase their risk of contracting HIV?
Every post I make begins with the assumption P=~P.
No, they just went to a population where HIV is already relatively common and a large number of people don't usually take adequate precautions against it (i.e. use condoms) and then studied the effects of the vaccine on that population's total infection rate over time.
How do you know? I RTFA, and I don't see it mention their procedures anywhere.
It's been reported fairly widely elsewhere. See, e.g., this article from the BBC:
Unfortunately, as the article notes, the sample groups may themselves be problematic. A previous study of another vaccine that was found to *increase* infection rates may not have been dangerous; they just neglected to control for circumcision and intravenous drug use. Given this study dates back to before the end of the previous study, their samples may be skewed the opposite direction. Circumcision has been found to reduce the risk of infection by 40-70%. IV drug use is insanely dangerous (I don't know the exact multiplier, but it is rather high). If the test group had a couple hundred extra circumcised individuals, or a dozen or so IV drug users, it could easily skew the results.
Of course, this is still overlooking another problem with the vaccine. It's not one injection, or even one plus a booster or two. It's a two vaccine regimen, with six injections of each component, for twelve total shots (they may eventually be combined, but that all depends on whether the components react with each other outside the body). And the duration of the protective effect is unknown, and likely short (since the vaccine doesn't seem to trigger the production of antibodies). Even if it was incredibly cheap, it's hard to get people to follow up for a second MMR shot, or keep up to date on their tetanus, both of which protect against diseases which are easier to catch without engaging in risky behavior. Can you imagine asking people to pay a few hundred dollars (a guess based on the cost of Gardasil), and visit the doctor half a dozen times to get such a relatively small benefit (reducing risk by about a third, with only two years of testing)?
Even if we assume the samples are good, this is only a first step, and a very short one at that.
In response to the PP: I suspect the confidence level is 95%. Most published studies require that level of precision, and no one likes to hamstring themselves by demanding greater confidence; after all, they spent a lot of money and rejecting the drug would waste it. Of course, if you've ever played D&D, you know how often you get fumbles or critical successes. 95% means the odds of it being insignificant could be as high as the odds of fumbling a roll.
$_ = "wftedskaebjgdpjgidbsmnjgcdwatb"; tr/a-z/oh, turtleneck Phrase Jar!/; print
that's all well and good, but if you don't understand statistics, you probably shouldn't be complaining about the statistics in a study that is undergoing peer review.
I'm not saying you're complaining about the study, I just don't think the excuse you presented holds water.
I have developed my own vaccine to HIV!
Simply subscribing to Slashdot makes you statistically 50% less susceptible to HIV!
I will take my 1 million dollar award in ten 100,000 dollar bills.
Seriously the study needs to be repeated and verified before anyone gets too excited.
It is not surprising that this was developed in Thailand due to the large sex trade there. Which makes me wonder about the demographic of the test subjects. Because of the large number of sex trade workers, any significant number in one group or the other will taint the results. If they were ALL sex trade workers that would be something different, however the article does not examine that detail. It could be that one group just happened to get 30% more sex trade workers than the other.
Also Slashdot I hate you and your stupid editor (not the person, the thing I am trying to type in).
You should still take precautions. Plenty of the tourists to Thailand do, by only sleeping with girls under 14. That means the girls have only had 5-6 years or so to contract the disease.
I don't believe in time. It's a grand conspiracy designed to sell watches.
If you're going to quote stats, get it right.
The #1 growing AIDS population is BLACK and HISPANIC woman in their 20's. No, I'm not a racist, but these are the facts you carefully omitted.
'Or are you claiming that once people believe they have the vaccine, that they will have more unprotected sex and thus increase their risk of contracting HIV?'
Of course they would. Perhaps you enjoy having sex with a piece of rubber but some of us prefer actual contact. Eliminating STD's and circumcision are two of the greatest causes known to man.
According to numerous online sources, raw numbers are:
51 out of 8187 found infected in the vaccinated group;
74 out of 8198 found infected in the control group.
The most basic course of statistics tells how to proceed from here: test if the null hypothesis (vaccine has no effect) remains plausible despite this evidence. Conditions are ideal for the chi-squared test.
We get Observed values 51, 74, 8147, 8123; Expected values 62.504, 62.496, 8135.5, 8134.5; then sum((O-E)^2/E) = 4.267, with two degrees of freedom.
Conclusion: the null hypohesis is rejected with only 88% confidence level.
This is not enough to confortably say that the vaccine has any benefit. Odds of the contrary are about 1/17.
This is much less reason to trust that the vaccine reduce infection rate by 31.1%, as reported in some press articles. Odds are 1/2 that it is less efficient than this.
Francois Grieu