HIV vaccine

[Cave Man]

While not there yet, this is most remarkable. For the first time there's statistical evidence of a vaccine that prevents infection (instead of disease, like other vaccines). Let's hope it can get done.

http://www.cnn.com/2009/HEALTH/09/24/hiv.vaccine/index.html

[Veldek]

It's good to hear that there's finally something working, although there are several problems with this vaccine:


30% are not enough for an international recommendation (yet). 80% would be needed. Of course one can hope that it can be improved now.
The test group might not have been big enough. Half of about 16,000 people got the vaccine, 51 from this group got ill, 74 from the other half.
Worst thing is: the scientists don't know why it works. It's a combination of two other vaccines that didn't work for themselves. The combination now has a 30% success rate, but noone knows why...

It's still a great success though, as it's the first time a vaccine worked anyway.

Source (in German): http://www.rp-online.de/public/article/wissen/gesundheit/761850/Die-Probleme-des-neuen-Aids-Impfstoffs.html

[leekohler]

I'll believe it when I see it.

[barkomatic]

I'll believe it when I see it.

Exactly. Every few years there is a vaccine breakthrough that you never hear about again.

[eawmp1]

HIV, like influenza, evolves/genetically modifies quickly. A moving target will be hard to hit. However, ANY progress toward a vaccine is good news.

[leekohler]

HIV, like influenza, evolves/genetically modifies quickly. A moving target will be hard to hit.

Exactly why I don't see this ever being eradicated.

[.Andy]

The test group might not have been big enough. Half of about 16,000 people got the vaccine, 51 from this group got ill, 74 from the other half.
From your German sources do they talk about whether this is statistically significant? I assumed (possibly wrongly) that they wouldn't publicise this trial if the results weren't statistically significant.

Worst thing is: the scientists don't know why it works. It's a combination of two other vaccines that didn't work for themselves. The combination now has a 30% success rate, but noone knows why...
This isn't really a problem. There are plenty of things in medicine that work that we don't know how they work. As long as they can be proven efficacious and have an adequate safety profile.

[Gelfin]

Exactly. Every few years there is a vaccine breakthrough that you never hear about again.

They're actually advertising for trial groups on buses around the city here. First time I've ever seen that. Might not mean anything.

[leekohler]

They're actually advertising for trial groups on buses around the city here. First time I've ever seen that. Might not mean anything.

And how does that work exactly? If it fails you end up with HIV?

[Gelfin]

And how does that work exactly? If it fails you end up with HIV?

Funny you mention that, and I wonder myself, but they clearly anticipated it because the sign says something to the effect of "you cannot get HIV from the trial."

[leekohler]

Funny you mention that, and I wonder myself, but they clearly anticipated it because the sign says something to the effect of "you cannot get HIV from the trial."

OK, now I'm really confused. So how would they know it works? :confused:

[.Andy]

OK, now I'm really confused. So how would they know it works? :confused:
It's probably just a trial that they're recruiting a control population for.

[Cave Man]

The important thing about this trial is that, for the very first time, a vaccine has been demonstrated to prevent infection. This is remarkable in the sense that all other vaccines prevent disease, not infection. This is the "gold standard" of HIV vaccinology. I have not see the published findings (as it's a conference report), but my suspicion is that it's targeted towards the V3 domain of gp120 or gp41. The amino acids at these positions are highly invarient, which is why this is encouraging.

[leekohler]

It's probably just a trial that they're recruiting a control population for.

Layman's terms please. I didn't get past Biology 101. ;) I know what a control group is, but I don't see how it fits in with this trial.

[Gelfin]

OK, now I'm really confused. So how would they know it works? :confused:

Got me. Maybe by drawing blood and testing in vitro?

I admit I had a flash of concern that a few participants might unwisely overestimate their chances of ending up immune by participating in a trial, chances I'm assuming will in practice be similar to a "come in and let this radioactive spider bite you" trial.

I'm sure they're lecturing, though.

[Cave Man]

OK, now I'm really confused. So how would they know it works? :confused:

These trials (usually phase 2 or 3) are based upon a statistical likelihood that some of the individuals will get infected just living their lives. By comparing those who get the vaccine vs. those who do not (using an at-risk group, such as gay men in the US or heterosexual persons in Africa), then if there's a statistical decrease in those who receive the vaccine it would be suggestive of protection.

[.Andy]

Layman's terms please. I didn't get past Biology 101. ;) I know what a control group is, but I don't see how it fits in with this trial.
It could be a few different things. Firstly the trial Gelfin is alluding to is probably distinct from the one done in thailand mentioned by cave man in the OP.

For a trail of vaccine efficacy you need to use a high-risk population which is why africa and se asia or groups like prostitutes are often used for vaccine trials. Recruiting people from a low risk population means that you would need hundreds of thousands of people in the trial (usually not feasible) for enough events to to happen to obtain statistically significant results.

On the other hand there are lots of things that you can test in a low risk control population. For instance a survey of risky HIV behaviours i.e. unprotected sex, barrier contraceptive use, needle-sharing etc to guide public policy. Or if you're going down the biological path then as gelfin said you can use blood for in vitro work. Or alternatively test the side effects of a vaccine or new drugs in a healthy population (with remuneration of course). There's an infinite amount of studies one could do to understand HIV without direct studying it. Remember that the host is as important, if not more important the than virus itself in this infection :).

[Shivetya]

While not there yet, this is most remarkable. For the first time there's statistical evidence of a vaccine that prevents infection (instead of disease, like other vaccines). Let's hope it can get done.

http://www.cnn.com/2009/HEALTH/09/24/hiv.vaccine/index.html

Doesn't remove HIV from bloodstream so are they essentially carriers? In other words, while they might not contract it they still cannot have safe contact?

[Cave Man]

This vaccine appears to prevent infection. Without infected cells, one is protected from infection (and thus cannot transmit). They will have to improve efficacy for licensure, but this is the only vaccine in history that prevents infection. A good start, but a ways to go.

[Eraserhead]

The important thing about this trial is that, for the very first time, a vaccine has been demonstrated to prevent infection.

Well as i've been reading in a book called wisdom of the whores needle exchanges and accessible condom supplies and lube to the at risk groups (In most of the world: gays, sex workers and drug injectors) work pretty well.

Sadly many countries don't like helping those people much.

[Veldek]

From your German sources do they talk about whether this is statistically significant? I assumed (possibly wrongly) that they wouldn't publicise this trial if the results weren't statistically significant.The only thing they say is that "the low number of patients at least requires a bigger test group".

This isn't really a problem. There are plenty of things in medicine that work that we don't know how they work. As long as they can be proven efficacious and have an adequate safety profile.Good to hear :)

There's one other thing I forgot to mention from the article: the vaccine only decreases the odds of getting the illness. Unlike other vaccines it doesn't soothe the course of it.

[Cave Man]

Well, it doesn't look so promising after all (http://www.kaiserhealthnews.org/Daily-Reports/2009/October/12/HIV-vaccine.aspx). That's unfortunate.

[leekohler]

Well, it doesn't look so promising after all (http://www.kaiserhealthnews.org/Daily-Reports/2009/October/12/HIV-vaccine.aspx). That's unfortunate.

But also not surprising.

[sushi]

I'll believe it when I see it.
Agree.

HIV, like influenza, evolves/genetically modifies quickly. A moving target will be hard to hit. However, ANY progress toward a vaccine is good news.
Agree.

Another virus that needs work is the Herpes family of virus.

The virus is our biggest threat to our survival. HIV has been around since the 50's or maybe earlier. We still don't have a cure or vaccine for it.

Makes me wonder how bad the next one will be.

[Cave Man]

If you look at the most common causes for transmission, they have a lot to do with reckless behavior. Don't share needles, don't screw someone before you and him/her got tested (or at least use a condom), don't go to tatoo places that don't properly clean their equipment. It's so simple, and frankly I am starting to loose patience with people over this topic.

I feel the same way about alcohol, tobacco, fatty foods, etc., etc. We should ban all of those because they cause so many fatal diseases. :p

[leekohler]

... but so be it. For the most part (and yes, I know there is unfortunate things such as spoiled blood transfusions), HIV and HepB/C are epidemics that don't have to be. If you look at the most common causes for transmission, they have a lot to do with reckless behavior. Don't share needles, don't screw someone before you and him/her got tested (or at least use a condom), don't go to tatoo places that don't properly clean their equipment. It's so simple, and frankly I am starting to loose patience with people over this topic. But again, I guess I am too extreme in my demands for human behaviour....
Cheers,

Ahmed

To some degree, you're correct. However, since people are human and not robots, the human equation must always be factored in to any meaningful discussion on the topic. We aren't all the same, and we don't always make the best decisions. If that weren't the case, we'd live in a perfect world.