1. The State Of The Science:
Combination Prevention
Technologies
Perry N. Halkitis, PhD, MS
Professor of Applied Psychology, Public Health, and Medicine
Director, CHIBPS
New York University
Presentation for HealthHIV SYNChronicty Conference
April 20, 2012

2. Biomedical Approaches to
HIV Prevention
• Anti-HIV Microbicides
– advantage of being receptive-partner controlled
– vaginally or rectally applied gels, foams, and creams
– HIV-specific and nonspecific compounds
• Male Circumcision
– cost and infrastructure limitations especially in developing
world
– operational, religious, political, and logistic factors
• Vaccines
– Still under development
• PEP
– Long history of use in medical settings

3. Biomedical Approaches to
HIV Prevention
• Pre-exposure Prophylaxis (PrEP)
• Treating/HIV Treatment (including after
Targeting and Testing)

4. Treating
• HPTN 052 trials (NIAID, 2011)
– HIV+ individuals initiating ART decreased transmission rates
to sexual partners by 96%
• The Swiss Statement/Swiss Federal Commission for
HIV/AIDS
– “An HIV-infected person on antiretroviral therapy with
completely suppressed viraemia (“effective ART”) is not
sexually infectious, i.e. cannot transmit HIV through sexual
contact.”
– Contingencies
• the person adheres to antiretroviral therapy, the effects
of which must be evaluated regularly by the treating
physician, and
• the viral load has been suppressed (< 40 copies/ml) for
at least six months,
• there are no other sexually transmitted infections.

5. Treating
• Uganda Couples Study (Quinn, 2000)
– 415 heterosexual serodicsordant couples in
Uganda
– Viral load above 50,000 copies in the HIV-positive
partner was most strongly associated with the risk
of transmission: 23 infections per 100 person
years
– Viral load between 400 and 3499: 2.2 infections
per 100 person years
– Viral load < 1500: 0 infections

7. PrEP
• CAPRISA 004 trials (Karim et al. 2010)
– women receiving tenofovir gel were 39%
less likely to contract HIV than those
receiving placebo
• Pre-exposure Prophylaxis Initiative
(iPrEx) trials (Grant et al. 2010)
– HIV-negative gay men given Truvada had
44% lower infection rates than men given
placebo

8. PrEP
• Partners PrEP Trial (Baeten, 2011 )
• HIV-negative partners in serodiscordant
couples
• HIV-negative partners taking tenofovir had 62%
less risk for infection
• those taking, tenofovir plus emtricitabine
(Truvada) had 73% less chance of infection
– Tenofovir: 68% in women 58% in men
– Truvada : 62% in women, 83% in men

9. Biomedical Approaches to
Prevention
• Research supports the efficacy of some
biomedical interventions!!!

10. Biomedical Interventions
• Research also indicates less than optimal
results for other biomedical interventions
– FEM-PrEP study was halted in April 2011
• Failures related to adherence
• Among those who were on Truvada and
seroconverted
• 26% had detectable levels of tenofovir in their
blood in the last visit before they tested HIV
positive

11. What is Wrong with
Behavioral Interventions?
• There is questionable effectiveness of
behavioral interventions
– Focus on reducing risk for infection
– Focus on person-level factors such as
motivation, efficacy, temptation etc.
– Focus on rational decision making--social
cognitive frames
• Rational operators
– Perhaps unsustainable

12. But is the solution to HIV prevention a
complete shift from the behavioral to the
biomedical without any consideration to
psychological or social processes?

13. NO!

14. What Do the Biomedical
Studies Teach Us?
• Biomedical interventions despite their
high level of effectiveness, involve a
critical human component
• Biomedical interventions only work
when uptake and adherence are
optimized
• We cannot separate the person from
the intervention

15. What is the Solution?
• Combining the best of biomedical treatment
(e.g., PrEP or initiating HIV treatment) with
behavioral components
• Biomedical interventions would likely yield
even better outcomes if combined with
appropriate behavioral and /or social
interventions
• “Don’t throw out the baby with the bath
water!”

16. Why an Integrated Approach
to HIV Prevention
1. The success of biomedical
interventions is dependent on behavioral
factors affecting medication adherence
and treatment uptake (i.e., treatment
acceptability and use) (Weiss et al. 2008)

17. 2. Treatment adherence “sticking to the
regimen”) plays central role in biomedical
interventions including
treatment for HIV (U.S., DHHS, 2011)
PrEP (e.g., Grant et al. 2010)
PEP (e.g., Chacko et al, 2012)

18. 3. Adherence is influenced by a variety of
bio-psycho-social factors that may both
enhance and diminish this behavior
– Patient based factors
– Providers based factors
– Treatment based factor
– Contextual factors

19. 4. Biomedical interventions without
combined behavioral approaches have
shown suboptimal medication adherence
and treatment uptake
– only 27 %of drug users in need of the Hepatitis B vaccine
completed the required three dose regimen (McGregor et al.
2003)
– and only 28.2% of young women at a clinic who were
offered the human papillomavirus vaccine accepted and of
those who accepted only 55.7% completed all three required
doses (Moore, et al. 2010)

20. 5. Medication adherence and treatment
uptake of biomedical interventions can be
addressed by behavioral interventions
that enhance knowledge and build skills

21. 6. Behavioral approaches attend to
factors such as age, socioeconomic
status, developmental understanding,
gender, gender identity, sexual
orientation, culture, stigma, mental health,
substance abuse, attitudes, prior
knowledge

22. 7. Policy and recommendations have yet
to be established as to whether some
biomedical interventions (e.g. PrEP) will
be viewed as life-long or as short-term
solutions for high-risk individuals;

23. SO WHAT IS A BETTER
APPROACH TO HIV
PREVENTION MOVING
FORWARD?

24. The Biopsychosocial
Framework

25. Application to HIV Prevention
• Biological factors: the virus (e.g., PrEP
and treatment)
– emerging
• Psychological factors: the person
(behavioral intervention)
– established
• Social factors: the context (structural
intervention)
– only scratching the surface

26. The Social Factors
• Science clearly shows that HIV disease is
fueled by…
–Poverty
–Discrimination
–Homophobia
–Victimization
–Gender bias
•EXPLAIN THE PATTERNS OF INFECTION IN
GAY AND BISEXUAL MEN AND AFRICAN
AMERICANS

27. • The development of interventions and social
policies to address these social ills are critical
to HIV prevention
– Behavioral interventions: INSUFFICIENT
– PrEP/Biological interventions: INSUFFICIENT
– Behavioral + Biological: ALSO LIKELY
INSUFFICINET

28. A NEW GENERATION OF
HIV PREVENTION
BIOMEDICAL APPROACHES
+
BEHAVIORAL SUPPORT/PROGRAMS
+
SOCIAL POLICIES/STRUCTURAL
INTERVENTIONS

29. • PREP OR TREATING to deter infection from
the virus
• BEHAVIORAL SUPPORT to (1) support
uptake, adherence and maintenance (2)
develop and understanding of PREP, and (3)
to reinforce condom use and safer sex
strategies
• SOCIAL POLICY to combat social
inequalities and decrease vulnerability to HIV
infections

30. A 3-Pronged
Approach
• biological,
psychological, social
• just like we approach
HIV treatment with
combinations of
drugs across classes
• The most effective
HIV prevention
program and policy
will marry all 3
components