National Working Group on Microbicides The Basics of Microbicides Amitrajit Saha PATH January 2007

National Working Group on Microbicides What is a microbicide? Currently, they are being formulated as gels or creams applied with an applicator. Future formulations could include sponges, time-released vaginal rings or gels combined with barrier devices such as diaphragms or cervical caps. Microbicides are substances that can reduce the transmission of HIV and other STI pathogens when applied vaginally and, possibly, rectally. They are not yet available.

National Working Group on Microbicides Is there a need for microbicides?  Rising rates of HIV infections: 37.8 million people are infected worldwide (UNAIDS ‘04 report on the Global AIDS epidemic)  5.21 million people living with HIV/AIDS in India at the end of ‘05 (NACO)  STI prevalence of 22% in women attending RH clinic in New Delhi (Sex Trans Inf, ‘00)  Feminization of HIV  6/10 new infections are among women. Almost 50% of all infected people worldwide are women (UNAIDS)  39% of people living with HIV in India at the end of 2005 were women (NACO)

National Working Group on Microbicides  Women are biologically more vulnerable to HIV/AIDS  2-4 times more likely than men to get HIV from unprotected sex  Women may be less able to assert their rights  Economic need or dependency  Social and cultural norms  Gender-based violence  Current methods – abstinence, fidelity, and condom use – are limited and often require male consent, knowledge or cooperation  The power dynamics between MSM means that for example, the kothi population are often unable to negotiate safe sex Is there a need for microbicides?

National Working Group on Microbicides Comprehensive Strategies for Protection Protection Technology Economic Opportunities Social Power Source: Brady, Martha. Population Council, Conceptual Framework

National Working Group on Microbicides Microbicides would work by:  Killing or inactivating the pathogen (germ)  Creating a barrier between pathogen and vulnerable tissue  Interfering with entry of virus into target cell  Preventing replication once virus has entered the cell( ARV based)  Boosting the vagina’s natural defenses Eventually microbicides will combine two or more mechanisms of action

National Working Group on Microbicides 2. surfactants 3. entry inhibitors 4. anti-retrovirals 1. boosts vagina’s natural defenses Source: Shattock, R.; Moore, J. Inhibiting Sexual Transmission of HIV-1 Infection. Nature Reviews Microbiology. Vol 1, October 2003.

National Working Group on Microbicides What would vaginal microbicides be like?  Contraceptive or non-contraceptive  Coitally-dependent and -independent  May reduce risk of other STIs  Likely to be inexpensive and available over the counter  Could be used without partner’s cooperation or even awareness

National Working Group on Microbicides How could microbicides benefit people living with HIV/AIDS?  Could reduce risk of co-infection with other HIV strains  May help protect both partners  Could reduce risk of other STIs, yeast and bladder infections  May allow conception while protecting partner

National Working Group on Microbicides Microbicides & anal sex  Many people (women and men) need microbicides for anal sex  Creating an effective rectal microbicide is scientifically more complicated  Vaginal microbicides must be accurately labeled Image courtesy of

National Working Group on Microbicides Microbicides are a part of a spectrum of HIV prevention and treatment options Prior to exposure Point of transmission Treatment Behavior change Sterile syringe access and drug addiction treatment Blood safety STI screening and treatment Voluntary counseling and testing Vaccines Pre-exposure prophylaxis (PREP) Male circumcision Male and female condoms Anti-retroviral (ARV) therapies to reduce mother-to-child transmission Vaginal & rectal microbicides Cervical barrier Diaphragms Anti-retroviral (ARV) therapies Opportunistic infection therapies Basic care/ nutrition Post-exposure prophylaxis (PEP)

National Working Group on Microbicides Balancing act to minimize HIV risk condoms reduces risk by 80-90% ? consistency of use microbicides may reduce risk by 40-60% ? consistency of use

National Working Group on Microbicides Thank You