Joint trials of a microbicide to prevent HIV infections during sex conducted in India and Africa were aborted after safety reasons cited by an independent scientific committee concluded that there was increased risk of HIV infection for women. The trial involved the use of a chemical, cellulose sulfate or Ushercell, and the scientists found the women were more susceptible to infection when using cellulose sulfate compared to those who used a placebo gel. This is the second time that microbicide trials have been aborted-an earlier candidate called nonoxynol-9 was also found unsafe as the chemicals created ulcers which served as conduits for the AIDS infection.
With scientists unable to produce an AIDS vaccine, health officials had hoped that a microbicide in the form of a gel, cream, film, tablet, or sponge can be used in poorer nations where men refuse to use a condom. The idea of a microbicide is to kill HIV in the vagina and cervix, prevent any virus that escaped from attaching to a woman's cells, and block an enzyme, reverse transcriptase, which the virus needs to replicate.