The world’s biggest trial of “chemical condoms” will start in Johannesburg on Monday, and researchers hope to have the anti-HIV product generally available in South Africa in five years.
Meeting that target would revolutionise women’s lives. They would control the use of microbicides, also known as “chemical condoms”, without the consent or even knowledge of their sexual partners.
Microbicides — chemical or antibiotic agents used to destroy pathogens — are inserted by a woman into her vagina before sex. Depending on the strategy used, the microbicide should either kill HIV or prevent it from entering the woman’s body.
The London School of Hygiene and Tropical Medicines estimates that in three years a microbicide with a 60% efficacy, used by just 20% of women in 73 developing countries, could prevent 2,5million new infections.
More than 3 000 women in Orange Farm and Soweto in Gauteng have volunteered to take part in the trial, which is estimated to run for a three-year period at cost of about R210million. Two more research groups, in Durban and Mtubatuba, will soon join the trials.
The South African trial is part of a four-country project run by the international Microbicides Development Programme. Other study sites will start shortly in Tanzania, Uganda and Zambia. In all, 10 000 women will participate in the study, which is being wholly funded by the British Department for International Development.
Dr Jocelyn Moyes of Wits University’s reproductive health and HIV research unit says the ultimate goal is to create a cheap, effective and accessible way for women to protect themselves against HIV and other sexually-transmitted infections.
Microbicide development has bene-fits for women that go far beyond controlling the spread of HIV. Although PRO 2000, the microbicide being tested, has no known contraceptive effect, the ideal is to produce microbicides that do. Having contraceptive and non-contraceptive microbicides would increase women’s control over their reproductive health. Currently, a woman wishing to have children cannot have safe sex — microbicides would change this, yet, they lag behind vaccines in terms of funding.
One factor is that major pharmaceutical companies do not see microbicides as a big money-spinner, since the likelihood of their popularity in the wealthier parts of the world are believed to be slim.
PRO 2000 was developed by a United States not-for-profit organisation, which currently holds the patent rights. Its active ingredient is a negatively-charged compound that attaches itself to certain points on the outside of HIV particles, and thus blocks the virus from attaching itself to the vaginal cells.
The microbicide is a gel, which comes in a pre-packed applicator, similar to a tampon applicator. Each applicator is filled with about half a teaspoon of gel, which also provides lubrication during sex — itself a protective measure. It has to be inserted within the hour before sex, and researchers think it will be effective for a few hours.
When the volunteers formally enrol in the trial on Monday, they will receive what the researchers estimate is a month’s supply of applicators. More will be available on request. They will then be monitored monthly to check their health and HIV status. For ethical reasons, all the women have free access to condoms and will receive ongoing safe-sex counselling.
The PRO 2000 research, which is the largest of three microbicide studies currently under way in the country, is a phase three trial: it has already completed safety trials. If the microbicide lives up to expectations, this is the last hurdle before applying for registration with the Medicines Control Council for distribution and use in South Africa.
Microbicide trials are not new to South Africa. Several years ago research using a spermicide — nonoxynol-9 — as a microbicide ended abruptly when it became clear that women using the active compound were becoming infected at a higher rate than those using the placebo.
Scientists now attribute the trial’s failure to the fact that the volunteers were commercial sex workers who used the microbicide many times a day. This high level of use is believed to have contributed to vaginal inflammation, which facilitated HIV infection.