HIVTools Research Group The Public Health Impact of Microbicides Charlotte Watts Ph.D.

HIVTools Research Group Common Questions About Microbicides “If microbicides are less effective than condoms, won’t we be putting people at GREATER risk if we promote microbicides?” “Can microbicides really make a difference in the HIV epidemic?”

HIVTools Research Group London School of Hygiene & Tropical Medicine Charlotte Watts, Anna Foss, Lilani Kumaranayake, Peter Vickerman, Fern Terris-Prestholt Global Campaign for Microbicides Lori Heise Funding from the Rockefeller Foundation, DfID, Global Campaign for Microbicides, and USAID

HIVTools Research Group Confronting partial effectiveness Will individuals switch from condoms to microbicides because they are easier to use? Three forms of evidence suggest that introducing microbicides will lead to more protection rather than less  evidence on current levels of condom use  experience from family planning  insights from modeling

HIVTools Research Group Sex-workers in East Asia and Pacific: reported condom use in last sex act Source: FHI behaviour surveillance surveys ( )

HIVTools Research Group Men in Sub-Saharan Africa: condom use in last sex act* Source: Macro International behavioural surveillance surveys and demographic health surveys; Measure Evaluation

HIVTools Research Group Post Intervention Condom Use LocationPopulationCondom Use Notes 5 US cities High risk ♀ 17% Consistent use Nicaragua General pop 7% Consistent use Rwanda Married women 22% Regular use Cameroon Youth 24% Last act any partner Zimbabwe Sex workers 26% Consistent use USA STD clients 39% Consistent use Ukraine IDUs 24% High consistency Bangladesh Sex workers 23% Always use last week Indonesia Sex workers 34% Of sex acts protected Tanzania Truck stop ♀ 43% 100% use last 5 acts

HIVTools Research Group The reality of primary partnerships Many women are getting infected in their primary partnerships Consistent condom use difficult to achieve in stable relationships (few interventions have achieved consistent use in more than 30 percent of couples). The contraceptive aspect of existing prevention methods is a major barrier to their use.

HIVTools Research Group Will women stop using condms? 9 existing studies – Two designs: –1) condom only compared to condom plus gel or –2) condom only compared to hierarchy of prevention options (including FC and gel); –all but one focus on STD clients or sex workers 6 found that availability of additional protection options resulted in overall increase in consistent condom use 3 found some evidence of migration 3 highlight that consistent microbicide use could be achieved by women who could not use condoms

HIVTools Research Group Experience from Family Planning Addition of each new method increases overall number of protected acts and decreases unintended pregnancies. Adding a new contraceptive method to those available in an existing program increases overall use by about 12 percentage points, and decreases crude birth rate by 5.3 points. (Ross,J & E. Frankenberg.1993 Findings from Two Decades of Family Planning Research. Population Council)

HIVTools Research Group The Prevention “Trade-Off” A low efficacy method used consistently can achieve the same protection as a high- efficacy method used less consistently A 90% efficacious method (like condoms) used in 20% of sex acts, provides less protection than a: –70% efficacy used > 30% of the time –50% efficacy used > 40% of the time –30% efficacy used > 60% of the time

HIVTools Research Group Mathematical modeling suggests…. Under most circumstances, probable levels of condom migration do not increase risk of HIV transmission of individuals of sub-populations Condom migration is potentially a problem only where condom use is high (> 70%) AND achieved microbicide consistency is low (< 50 % of non-condom protected acts) (Foss et al, Shifts in condom use following microbicide introduction: should we be concerned?. AIDS 2003, 17: )

HIVTools Research Group Condom Consistency BEFORE AFTER 30% 5% 50% 32% 70% 59% 90% 86% Some reductions in condom consistency that can be tolerated without increasing risk Microbicide HIV/STI efficacy = 50%; Used in 50% of acts not protected by condoms

HIVTools Research Group Condom Consistency BEFORE AFTER 30% 0% 50% 0% 70% 37% 90% 79% Reductions in condom consistency that can be tolerated without increasing risk Microbicide HIV/STI efficacy = 50%; Used in 100% of acts not protected by condoms

HIVTools Research Group What should the message about microbicides be?

HIVTools Research Group “Harm reduction” approach Microbicides would be promoted as an adjunct or “back-up” to condoms, not as a replacement. Prevention messages would shift to a hierarchy of options: –Use a male or female condom every time you have sex; if you absolutely can’t use a condom, use a microbicide –Use a microbicide with your condom for added pleasure and protection

HIVTools Research Group Positioning microbicides Microbicides could be promoted specifically for use with regular partners or spouses. Need to ensure that not associated with lack of intimacy / trust => not have the same association as condoms Microbicides could be potentially be positioned as a vaginal health and hygiene product, or associated with protecting fertility by preventing RTIs.

HIVTools Research Group The message should NOT be: “Microbicides can replace condoms.” “Microbicides will solve gender inequity and power imbalances in relationships and society that put women at risk.”

HIVTools Research Group “Can microbicides really make a difference in the HIV epidemic?”

HIVTools Research Group Mathematical modeling of impact on HIV transmission Data from 73 lower income countries (countries with GDP < $1200 and all of Sub-Saharan Africa) Analysis uses country specific demographic, epidemiological, and health care data where available for key sub-populations: –youth –regular partners –sex workers and clients –IDUs and sex partners

HIVTools Research Group How do the models work? Initial data inputs: –underlying prevalence of STDs/HIV –levels of contact with services –condom coverage & consistency of use; “migration” –efficacy of microbicide against HIV & STD Model calculates patterns of spread of HIV & STDs over time, with current interventions only, adding on microbicides Generates estimates of HIV infections averted over time with and without microbicide

HIVTools Research Group 20% Infections averted

HIVTools Research Group Results: Potential public health impact Introduction of a 60% efficacious microbicide in 73 lower income countries would avert 2.5 million HIV infections over 3 years (in men, women & infants) –assumes microbicide is used by 20% of those individuals likely to be reached by existing services –microbicides used in 50% of sex acts where condoms are not –assumes 10% migration away from condom (Watts et al, 2002)

HIVTools Research Group Economic Benefits Health care costs averted$2.7 billion (includes only forms of care currently available--no ARVs) (uses country-specific estimates of access to health care) Productivity benefits $1.0 billion (includes time lost for work; training of replacement staff) Watts, et al, Rockefeller Microbicides Initiative Public Health Impact Working Group, 2002

HIVTools Research Group Impact is driven by coverage %20%30% Coverage of groups in contact with services Cumulative HIV infections averted (millions) Productivity gains and savings to Health System (billions US$2002) Total HIV avertedDirect savings to health systemPresent productivity gains

HIVTools Research Group Public health conclusions Even a relatively low efficacy microbicide, used by a relatively large number of women could have an important effect in preventing HIV and STDs. Introduction of microbicides would result in substantial savings in health expenditures and productivity. Coverage (access) and consistency of use are crucial determinants of the public health impact of microbicides.

HIVTools Research Group Conclusions Even during trials need to look forward to future promotion and distribution strategies Positioning, messaging and access are key to achieving the desired impact of microbicides. More research needed on: –how women in different settings likely to use microbicides –Different women’s preferences about accessing microbicides –how individuals understand and implement hierarchical prevention messages –ways to promote microbicide use in primary partnerships