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Comment by scott_s | Hacker News Reader

I'm confused by the statement that a vaccine would not be a game changer in terms of worldwide infection. Right now, the only way to reliably prevent HIV infection is through changing behavior, which is extremely difficult. But widespread use of a vaccine would just require a one-time injection, which is relatively easier.

I'm further confused by your polio reference, because that sort of effort would only be possible with a vaccine.

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EDIT: I actually meant smallpox when I was talking about polio. That's a big error; corrected it above. Thanks rdl.

I should have been more specific - I meant that if we did develop a vaccine, then it makes following the [smallpox] example theoretically possible, but this is still extremely challenging due to the reasons given.

Although you and I might have the vaccine, not everyone has it - not by a long shot - because not everyone is born in a modern westernized hospital. These people are protected by virtue of an extreme mobilization to literally isolate every single instance of the virus. It (hopefully) only exists in the lab at this point.

You may be thinking of smallpox, which exists in one or two declared labs (and probably a few more black labs).

Polio is unfortunately still "in the wild" in certain areas (Afghanistan/Pakistan/India, Sub-Saharan Africa), and had a bit of a resurgence lately. The Gates Foundation is putting a lot of effort into finishing up polio eradication.

Relevant TED talk: http://www.ted.com/talks/bruce_aylward_how_we_ll_stop_polio....

One of the main issues is that the polio vaccine requires a cold chain (presently; I think they have a new shelf-stable one); the smallpox vaccine, at least one of them, does not.

FYI, there has been only 1 reported case of Polio in India this year (since January). It might be that time when Polio is finally eradicated from India

http://arstechnica.com/science/news/2011/09/polio-in-india-g...

And there have been dozens of cases of wild polio in China and the Philippines this year, and a current outbreak of 84 cases in Pakistan, according to the WHO. http://www.who.int/csr/don/en/index.html

I agree with that. Thanks for clarifying.

Not everyone needs to be vaccinated for the phenomenon of 'herd immunity' to kick in:

http://en.wikipedia.org/wiki/Herd_immunity

Actually, circumcision is a proven way to reduce infection rates that doesn't involve behavior. Though, as one might imagine, it can be a tough sell in cultures where that isn't the norm.

Just because infection rates are lower among males who are circumcised doesn't mean it prevents infection. http://en.wikipedia.org/wiki/Correlation_does_not_imply_caus...

Neat.

Except there have been dozens of randomized, controlled studies that show circumcision significantly reduces risk of infection.

http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fj...

http://www.sciencedirect.com/science/article/pii/S0140673607...

http://www.sciencedaily.com/releases/2006/12/061213174708.ht...

http://journals.lww.com/aidsonline/Abstract/2000/10200/Male_...

Only amongst people who don't use condoms.

This guy presents a fair scientific examination of whether to circumcise: http://www.youtube.com/watch?v=i2gloq-prkA

Then why does the USA have the highest rate of circumcision and also the highest rate of HIV infection of developed countries? I don't think the claim holds up under scrutiny here.

[EDIT: wording]

Actually, this is a reasonable observation. But it actually does make sense.

My understanding is that many (all?) of these studies have been conducted in sub-Saharan africa. The environment in which AIDS spreads may be very different in developed countries. The presence of secondary infections, unhygienic conditions, and other social norms may play a big role in the spread of aids and greatly amplify the protection that circumcision provides. The evidence does look compelling.

Now, if the infection rate is already low, secondary STDs are rare, hygiene is at a very high standard, and transmission vectors are different, then the effects might be much less pronounced. I suspect it would be hard to create a controlled study of this in Europe, since you'd have to convince a large number of men who are probably in a very low risk group to be circumcised.

Thank you for expanding on my admittedly rushed comment. I agree that comparing health data in the US to that of developing countries is problematic. But it raises interesting questions.

One question, that I don't think has been answered sufficiently is that the controlled trials and published studies have been criticized for possibly overstating the effectiveness of treatment. (The trials were stopped early on ethical grounds which can overestimate the effects being tested.) Wikipedia has a fairly comprehensive roundup: http://en.wikipedia.org/wiki/Circumcision_and_HIV#Randomised...

I think my bigger point, though, is that it's easy to look at data and say, "Aha! This one thing is the solution" without stepping back and looking at all the different pieces that make up the big picture. It's going to take some combination of education, prevention, vaccination, and health policy to tackle this disease.

You don't think which claim holds up? That circumcision cuts infection rates? As I posted in a comment below, there's a fair bit of scientific evidence to support that.

The US has a wide range of ethnic, cultural, and socio-economic diversity that throws off a lot of statistics when compared to other, relatively homogenous developed countries.

Circumcision has well known downsides, and its effectiveness is limited (~50%) so people would still need to wear condoms to be reasonably safe.

Of course you should use condoms, not share needles, and get tested regularly.

But a 50% decrease in new HIV infections is huge!

It can be a tough sell because it's almost always forced genital mutilation carried out on defenceless infants violating their human rights and causing irreversible damage or done by pressuring men into it without telling them the downsides.

Not to be pedantic, but is it the case this would only be a single injection? I believe that some vaccines can need repeat/regular treatments over a (relatively short I think) period of time.

If that were the case here it would make vaccination much harder, though still possible of course.

That's a fair point, but I still think that's an order of magnitude easier than changing life-long behavior regarding sex partners.

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