Rumor Control: Can I Contract HIV From an Experimental AIDS Vaccine?

Absolutely not. Here's how vaccines work: They help train our bodies to ward off diseases. They trick the body into thinking it already has an illness. This triggers the immune system to build an army of defenders, called antibodies, to attack the fake infection. The antibodies remain on call to protect us against future assaults. But antibodies are disease-specific. These microscopic warriors guarding against one sickness don't work when other infections invade.

Most vaccines for familiar diseases -- think the measles, the flu and human papillomavirus (HPV) -- employ harmless, weakened or dead disease cells, known as antigens, to trigger the body's defensive response. However, several different types of vaccines exist, including the following:

• Live-attenuated -- made by weakening the virus until it's still alive but can't cause serious harm. In most cases, the worst that can happen is a runny nose.
• Inactivated -- scientists completely kill the virus and then incorporate dead pieces of it into the vaccine. There is no possibility of getting symptoms of the disease, but because the cell ingredients are dead, the vaccine doesn't last very long.
• Synthetic -- these contain man-made material and therefore are considered safer than live, weakened or even dead virus.

Experimental HIV vaccines contain synthetic components only -- no virus is injected into volunteers, and you can't get HIV from them. By the way, there are two types of experimental HIV vaccines: Preventive varieties are intended to keep HIV-negative people from becoming infected; therapeutic strains are designed to strengthen the immune systems of those already HIV-positive.

So what happens after scientists develop an experimental HIV vaccine in the lab? Researchers first immunize primates to test whether the inoculation works. Only after experiments with our animal cousins prove the vaccine safe and effective do researchers initiate testing in humans, a process that requires several phases. If the experimental vaccine proves safe and effective in people, the Food and Drug Administration (FDA) approves it for medical use. The human stage of this testing process alone may take up to a decade.

Currently, many experimental HIV vaccines are being tested in human beings. But even though Blacks are disproportionately infected -- the Centers for Disease Control and Prevention projects that 1 in 16 African American men and 1 in 30 African American women is expected to be diagnosed with HIV in their lifetime -- few Blacks are enrolled in HIV-vaccine trials.

What's up?

"There are conditions that contribute to lower enrollment," says Kevin Trimell Jones, research-projects manager at the University of Pennsylvania's HIV/AIDS Prevention Research Division. These include residual mistrust from the Tuskegee Syphilis Study and the fact that many predominantly Black neighborhoods lack access to HIV information, testing sites or knowledge of how trials contribute to the quest for a cure.

Yet if we want the HIV vaccine to protect us once one is approved, Black people must participate in clinical trials.

That's where people like Jones and the University of Pennsylvania HIV-prevention team come in. "We try our best to get permission and buy-in" from communities where many Black Americans are affected by HIV, either directly or indirectly, he says. Then, working out of mobile vehicles, Jones and his team fight the pandemic by engaging in outreach in neighborhoods with a high incidence of HIV/AIDS and other STDs; for example, teaching HIV-prevention and safer sex techniques, dispelling myths and rumors and talking to community members about the war against the pandemic. They also encourage qualified people to volunteer for HIV-vaccine trials.

When the dialogue is successful, Jones says, people begin to understand that "their participation will help inform the next stages of research, whether that's a vaccine that works or a contribution to the body of knowledge that will eventually grant the vaccine we're all hoping for."

How can you get involved? Help advance the next phase of preventive HIV vaccine research by learning more about clinical trials and then locating a trial near you. If you're an HIV-negative gay or bisexual man looking to participate in a vaccine study, go here.

New York City resident Ramon Johnson is the gay-life guide at about.com, part of the New York Times Company.