Despite efforts to promote sex education and condom use, HIV rates are not declining. It couldn't be clearer: We need other options to stem the tide of sexually acquired HIV cases. So it is nice to report that an experimental rectal microbicide (a gel containing HIV drugs to block HIV transmission) has been improved.

The gel, containing Viread (tenofovir), had issues associated with side effects that undercut its effectiveness as well as its tolerability in the MTN-007 trial. Researchers developed a low glycerin version of the gel, and voilà—fewer problems. Next: a trial in South Africa, Peru, Thailand and the United States to test the new gel.