A new HIV drug that uses antibodies to attack the virus has shown promise in human studies, the first time such a drug has reached phase one clinical trials, researchers announced Wednesday. Infected patients who received the drug saw a 300-fold drop in the amount of HIV in their blood, referred to as the “viral load.” The success of the trial suggests that immunotherapy -- using the body’s own immune system to fend off pathogens -- could lead to better ways of preventing and even curing the disease, according to Microfinance Monitor.

The antibody, called 3BNC117, may actually kill HIV-infected cells instead of just suppressing them, researchers noted. “We conclude that, as a single agent, 3BNC117 is safe and effective in reducing HIV-1 viraemia, and that immunotherapy should be explored as a new modality for HIV-1 prevention, therapy and cure,” Michel Nussenzweig of the Howard Hughes Medical Institute at Rockefeller University in New York wrote in the study, published online Wednesday in the journal Nature.

Both HIV-positive and HIV-negative patients involved in the trial were given a single dose of the drug intravenously and monitored for two months. A week after being given the dose, subjects who were HIV-positive showed a 300-fold decrease in their viral loads. However, researchers had their doubts about whether such short-term success was an indication of life-long defense. “One antibody alone, like one drug alone, will not be sufficient to suppress viral load for a long time because resistance will arise,” Dr. Marina Caskey, co-author of the study, told Yahoo News. Previous tests involving HIV antibodies were not so promising, according to the Independent.

HIV, or human immunodeficiency virus, works by attacking the body’s immune system – the network of tissues, organs and cells that act as a natural defense against disease. The virus latches onto those cells, weakening the immune system and allowing other common pathogens to take hold.

There are two types of HIV, called HIV-1 and HIV-2, and both can be transmitted through sexual contact. However, the predominant virus and the one that seems to spread more easily is HIV-1.

Although the recent study has given researchers hope in the fight to end HIV/AIDS, a global killer that affects an estimated 35 million people worldwide, it could be many years before a vaccine that fully protects against HIV reaches full development.