Why Microbicides?

Why are Microbicides Important?
Microbicides could provide women with a method, which they control, to prevent HIV/AIDS.

Biologically, women are far more vulnerable than men to HIV infection during a single sexual encounter.

A number of substances are being tested as potential microbicides and nearly a dozen microbicides have entered human testing.

A safe and effective microbicide will put the power of protection from HIV infection in the hands of women and will save millions of lives.

Conservative estimates suggest that the introduction of even a partially effective microbicide could result in 2.5 million averted cases of HIV over three years.

Estimated cost savings to developing country governments from the introduction of a microbicide are $3.7 billion.

The need for microbicides is significant and urgent

• Despite the knowledge of successful HIV prevention strategies – condom use, reduction in the number of sexual partners, diagnosis and treatment of sexually transmitted infections – HIV continues to spread at an alarming rate especially among women in developing countries. HIV has also now become a threat to American women. At the end of 2003, the CDC estimates that 405,926 persons were living with AIDS in the USA; an estimated 170,679 of these are adult and adolescent women.

• Without a preventive HIV vaccine, microbicides offer an alternative to condoms as the most feasible method for primary prevention of HIV.

• Currently available HIV prevention techniques are often not feasible for many women who live in resource poor settings. The availability of microbicides would greatly empower women to protect themselves and their partners. Unlike male or female condoms, microbicides are a potential preventive option that women can easily control and do not require the cooperation, consent or even knowledge of the partner.

Microbicides may also provide women with a safe; effective contraceptive that they can control
Nonoxynol-9 is a spermicide which has been in widespread use as a contraceptive for many years. It is available over-the-counter in different formulations (gels, suppositories and film) and can be used alone or as additional protection on top of condoms, diaphragms or other physical barrier methods.

Considerable research has been done on the safety and effectiveness of Nonoxynol-9 for HIV prevention. WHO, in collaboration with the CONRAD Program, convened a technical consultation in October 2001 to review the data on the use of Nonoxynol-9 as a spermicide.

Key conclusions from the technical consultation include:

• Although nonoxynol-9 has been shown to increase the risk of HIV infection when used frequently by women at high risk of infection, it remains a contraceptive option for women at low risk.

• Nonoxynol-9 offers no protection against sexually transmitted infections such as gonorrhea or Chlamydia.

• There is no evidence that condoms lubricated with nonoxynol-9 are any more effective in preventing pregnancy or infection than condoms lubricated with silicone, and such condoms should no longer be promoted. However, it is better to use an nonoxynol-9 lubricated condom than no condom at all.

• Nonoxynol-9 should not be used rectally.

• Evaluation of other potential microbicides should continue.

An effective OTC microbicide can use the same distribution system as condoms

Distribution of microbicides will be influenced to a large extent by whether they are available for sale by prescription or over-the-counter (OTC). If an effective microbicide becomes available for use on the market as an OTC it can use the same distribution system as condoms. Their use can be advocated for in HIV/AIDS, STI, maternity and family planning clinics, and in youth or adolescent health care. Health care personnel working in this variety of settings can be trained in the use – and importance – of microbicides.

A microbicide could have a substantial impact against the global HIV epidemic

A recent cost-benefit analysis conducted at the London School of Hygiene and Tropical Medicine indicates that the introduction in 73 lower-income countries of a microbicide which reduced the risk of infection by 40%, at 30% coverage, would avert approximately 6 million HIV infections over 3 years in men, women and children. In addition, this would reduce the health care costs (excluding the cost of antiretroviral therapy) by a staggering 3.2 billion US dollars. This implies that a microbicide with relatively low-effectiveness could have a substantial impact against the global HIV epidemic if it were used by a significant number of women.