Rectal gel to block HIV

A rectal gel to prevent HIV transmission through anal sex is a step closer after a successful trial on monkeys was published this month.

Researchers at St George’s University of London found most monkeys who were given the anti-retroviral drug tenofovir as a concentrated rectal microbicide were protected from SIV, the simian version of HIV.

Eight of nine monkeys given the tenofovir gel up to two hours before exposure to the virus were protected, whereas all the monkeys not given the gel and three of four monkeys given a placebo became infected.

These results indicate that colorectal pretreatment with ARV drugs, such as tenofovir, has potential as a clinically relevant strategy for the prevention of HIV transmission, study author Martin Cranage concluded.

However, the Public Library of Science journal cautioned that successful animal trials do not always lead to success in humans.

Clinical trials of a potential vaginal microbicide that worked well in macaques were halted recently because women using the microbicide had higher rates of HIV infection than those using a control preparation, the editor’s comment stated.