Could a shot given every one to three months reduce the risk of getting HIV? WGGB.com reported that new research suggests that the answer is yes.
In two studies, wrote Nature, researchers showed that an antiviral drug injected into muscle of macaque monkeys protected them from infection for weeks afterward.
These findings were published in the journal Science. Similar results from a study conducted by researchers at the U.S. Centers for Disease Control and Prevention (CDC) were also found.
According to Nature, David Ho, a virologist at the Aaron Diamond AIDS Research Center and a co-author of the study published in Science, and his colleagues, who included researchers from GlaxoSmithKline, studied an experimental drug called GSK744.
GSK744 is a highly potent analogue of dolutegravir (sold as Tivicay) which was approved by the U.S. Food and Drug Administration for HIV treatment last year.
GSK744 is in a class of antiretroviral drugs called integrase inhibitors. These medications block HIV from inserting its genetic material into the body's immune cells.
GSK744 is not soluble in water, so the researchers melted it and crystallized it into nanoparticles which they suspended in solution. When injected into muscle, this fluid forms a ‘depot’ and slowly seeps into the blood and tissues, including the rectum, where HIV exposure can occur. The depot allows the agent to stay around for three to four months.
GSK744 protected the monkeys from repeated attempts to infect them with a hybrid simian/human AIDS virus called SHIV.
Ho and his team squirted a solution containing SHIV into the rectums of 16 macaque monkeys once a week for eight weeks. Half of the monkeys received two injections of GSK744 during that period. The other half, which was the control group, did not.
All the monkeys that received GSK744 were protected. Those in the control group became infected.
CDC researchers gave six monkeys shots of the drug every four weeks; six others got dummy shots. All were exposed to the virus twice a week for 11 weeks.