A new approach in the enduring search for a vaccine to eradicate HIV is the focus of clinical trials beginning in San Francisco among other cities and serves as the subject for an interesting health piece in the Chronicle. The new tactic, known as passive immunity, might be seen as something of a workaround or stepping stone on the way to a proper vaccine — but you knew that a real, honest-to-god cure for HIV remains elusive. Still, the approach could present a a key piece in a puzzle whose proportions are still taking shape: Namely, what antibodies work to fight the virus.

The trial is called the AMP HIV Prevention Study, an acronym for Antibody Mediated Prevention. If vaccines are injections of a virus that spark an immune reaction of antibodies, trains those antibodies to defend against an infection, this study is interested, by contrast, in passive immunity. That process relies on injecting patients with antibodies instead of forcing their bodies to create them, and then seeing how those work.

"In traditional vaccine studies, we give people a vaccine and wait to see if their bodies will make antibodies against HIV in response," reads an overview on the study's website. "In this study, we’ll be skipping that step, and just giving people the antibodies directly. We will do this through an infusion, which some people know better as getting an IV or getting a drip. This is the first study testing whether this antibody can prevent HIV infections in people."

Assuming the antibodies are successful, the next step would be finding a way to make bodies produce them on their own. "This is a very important experiment.Stanford biochemist Peter Kim tells the paper. "It will tell us whether or not having these antibodies in a person actually does prevent disease.”

The study, by the way, is still seeking HIV-negative transgender people and/or men who are sexually active with men. Here's some info about that, in case in the spirit of this year's pride someone feels like pursuing it.

Dr. Susan Buchbinder, who is in charge of the Department of Public Health's San Francisco trial, summarizes the push: “What we’re testing isn’t what we would assume would be the final product," she says, "But this will give us a benchmark,”

Related:PrEP On-Demand: Startup Rolls Out HIV-Prevention Drug Delivery