This year was one the most exciting in HIV prevention. It started very well — with results of the ALVAC-AIDSVAX trial in Thailand, the first-ever proof of HIV vaccine effectiveness. The trial’s protection rate of 31 percent may be modest, but it is a first victory of its kind.

The vaccine is not good enough to be mass-produced, but it is a proof of concept, according to Mitchell Warren, executive director of AIDS activism group AVAC (AIDS Vaccine Advocacy Coalition).

In July 2010, a South African-led microbicide trial called Caprisa 004 — based on the use of a vaginal gel — saw a 39 percent effectiveness against infection.

“It is partial protection, but nevertheless groundbreaking,” Warren says. “Now we have to make them better, as trials answer some questions and raise additional ones.”

That same month, scientists from the National Institute of Allergy and Infectious Diseases announced its discovery of three human antibodies that can neutralize 90 percent of circulating HIV-1 strains.

Then there’s the incredible results of the iPrEx trial, which combined two antiretrovirals, the drugs given to HIV-positive patients, to reduce the risk of HIV infection in healthy people. In the study, 44 percent of men were less likely to contract the virus with the pill.

How far are we from an effective HIV vaccine?

“Eighteen months ago, I would have given you a different answer,” Warren says. “We are closer that we ever thought we would be in the last few years. But as much as we want big surprises, science works in small steps. We moved a few steps in 2010, but we have more work to do.”