http://www.guardian.co.uk/world/2009/sep/24/hiv-infection-vaccine-aids-breakthrough

Apparently will reduce risk of infection by a third. Even "just" a third makes this discovery HUGE, as most of you probably figured out. Also, as the article states:

"The world's largest HIV/Aids vaccine trial of more than 16,000 volunteers was the first in which infection has been prevented, according to the US army, which sponsored the trial with the National Institute of Allergy and Infectious Diseases."

I will also add that as yet again the article states, the results of this discovery right now only apply to HIV strains that are local to Thailand, so it's unknown as to whether it will be effective against other strains in different parts of the world. At any rate, this is a wonderful lead to follow in the effort of ultimately defeating the virus.

How the hell do they test this? Inject a bunch of people and then expose them to HIV?

Obviously not. So how do they know infection was prevented by this vaccine?

Statistics. A large group of people given the vaccine got less aids then a large group given a dummy vaccine. The amount was lower enough to be statistically significant, meaning its very unlikely to be because of chance.

Though I agree that it does sound rather far-fetched when dealing with aids.

This is correct, and also in accordance with the article. Why does it sound far-fetched with viruses, though? (Sincere question, I don't know much about microbiology.)

What if the group that received less AIDS was exposed to less AIDS? Maybe they weren't going around all willy-nilly with their peckers out while the group that got tons of AIDS went from port to port, ****ing every hooker in sight?

That's why they do statistical analysis, you ignorant moron.

Yes sir, I only had sex with two hookers this month. They did not have the HIV, I swear.

Well, this proves that progress is being made.
And that is fantastic.

They have a test for HIV. I suggest you try it out, you wretch.

I'd rather not know if I have it. I can sleep easier, thanks.

Confidence interval.

You can sleep easier not knowing whether or not you have an incurable disease?

Perhaps he meant "sleep (with other people)" easier.

they probably used blood samples to test it...or an animal

They did not do that. Did you read the article, or this thread?

was there food?

The uncooked flesh of apes and monkeys. Don't worry about the effect on the population; they only culled the most sickly ones.