A major implication of research showing the microbicides – and of course semen – are taken up into the uterus is a strong suspicion that this may be where HIV infection occurs. This has led to renewed interest in preventing this using internal barrier methods, such as reusable silicone caps, which may also be turned into a means of delivering (and removing) microbicides from a woman’s vagina.

Perhaps surprisingly, there has still been no randomised controlled trial to look at the effectiveness of internal barriers in preventing either HIV or other STIs, although in 2002 a collaborative research project between the University of Nairobi in Kenya and the University of Washington in the USA began recruiting women from clinics treating STIs into a clinical trial to look at the recurrence rates of gonorrhoea and chlamydia when diaphragms are or are not used. The goal was to recruit 400 women, each to be followed up for eight weeks at two week intervals (Cohen).

In Zimbabwe, women have been enrolled in a two month programme to help them use condoms more effectively. Those who remain inconsistent in their use of condoms are then recruited into a diaphragm acceptability study, in which they are taught how to apply a diaphragm to protect the cervix, and encouraged to use it with KY jelly. Preliminary results, from the first 156 women enrolled, are that almost all used the diaphragms, and more than half used them more than half the time while having sex (van der Straten).