Oral Abstract Session 01 - Global HIV Vaccine Enterprise

POSTERS
Posters
Topic 9: Non-Vaccine Prevention
P09.17
Female Sex Workers and Condom Use: Lessons for
Future HIV Vaccine Trial in Nigeria
O. Fakunle 1 , A. Adeyemi 2 , O. Busari 3 , O. Adesola 4
1 University College Hospital, Ibadan, Nigeria; 2 MEASURE,
Abuja, Nigeria; 3 Federal Medical Center, Ido-Ekiti, Nigeria;
4 Mainland Hospital, Lagos, Nigeria
Background: Condom remains one of the most effective means
of HIV prevention in the absence of proven, safe and effective
vaccine. Nigeria has a surveillance system that monitors HIV
trend among most-at-risk populations. Female sex workers (FSW)
have the highest HIV prevalence compared to other groups. Since
the ultimate goal is to prevent new infection, there is a need to
evaluate condom use among FSW and the lessons will be vital for
future HIV vaccine trial.
Methods: Secondary data analysis of 2010 Integrated Bio-
Behavioral Surveillance Survey was done with 4559 brothel
and non-brothel FSWs in 9 Nigerian states. The survey involved
HIV testing. Administered questionnaires had information on
socio-demographic, HIV, sexual/reproductive health variables.
Predictors of consistent condom use were evaluated using
multiple logistic regression models.
Results: The median age was 26years (15-49years); median age
at first sex was 17years (11-22years); average clients/day was
4; 38% had ever been married with 8.1% currently married and
3.7% living with their spouse; 74.6% used condom consistently;
47.4% completed at least secondary education; 53.6% had been
away from home for more than 1month; 60.2% tested and
received HIV result within the last 12months; and 91.2% knew
that condom could protect against HIV. Significant predictors of
consistent condom use include testing and knowing result for
HIV OR=1.9 95%CI:1.4-2.5; being away from home for ≥1month
OR=1.4 95%CI:1.1-1.9; engaged in sex trade for 24months or
less OR=2.7 95%CI:2.0-3.7; those that had 4 or more clients per
day OR=1.7 95%CI:1.3-2.3) and those aged 25years and above
OR=1.4 95%CI:1.1-2.1.
Conclusion: Older FSW with shorter duration in sex trade, having
more clients, aged above 25years and away from home are more
likely to use condom consistently. Lessons from condom uptake
among FSW may lead to targeting FSW with these features for
inclusion criteria for HIV vaccine trial in Nigeria.
208
AIDS Vaccine 2012
P09.18 LB
Infrequent, Low Magnitude HIV-Specific T Cell
Responses In HIV-Uninfected Participants In The 1%
Tenofovir Microbicide Gel Trial (CAPRISA004)
W.A. Burgers 1 , T.L. Muller 1 , A. Kiravu 1 , V. Naranbhai 2 ,
S. Sibeko 2 , L. Werner 2 , Q. Abdool Karim 2 , S.S. Abdool Karim 2
1 University of Cape Town, Cape Town, South Africa; 2 CAPRISA,
Nelson R Mandela School of Medicine, Durban, South Africa
Background: Macaque studies of antiretroviral-containing
microbicide gels administered rectally or vaginally followed by SIV
challenge have documented priming of SIV-specific T cell responses
in the blood of protected animals. This concept has been termed
“chemo-vaccination”, where aborted viral replication is thought
to leave an immune footprint of exposure, which may augment
protection provided by microbicides/PrEP. We investigated
whether T cell responses were detectable in women participating
in CAPRISA004 1% tenofovir microbicide trial, which showed 39%
efficacy in reducing HIV acquisition.
Methods: Thirty-eight HIV-uninfected participants were selected
based on consistently high gel use and a high number of recorded
sex acts over the duration of the trial. Cryopreserved PBMC were
stimulated with HIV-1 peptide pools based on the HIV-1 clade
C proteome, and IFN-gamma production was measured by the
ELISPOT assay. Positive response were defined as >55 SFU/106
PBMC. Samples were tested at the visit at which preceding
monthly coital activity was the participant’s highest, and at study
exit. Assays were conducted blinded to placebo or tenofovir arm.
Results: T cell responses were detected in 1/18 tenofovir and
2/13 placebo participants at the high gel use visit. Responses
were of low magnitude (between 60 and 100 SFU/106 PBMC),
and directed at peptide pools from HIV Gag, Pol, Nef and Env.
T cell responses were not detected at the exit visit. These data
suggest that HIV-specific responses are infrequently detected
in blood in uninfected participants from a clinical trial of a
vaginal microbicide, and where present, are of low magnitude
and transient.
Conclusion: Magnitude and timing of viral exposure may account
for differences in detecting systemic T cell responses between
preclinical studies in non-human primates and a human clinical
trial of a vaginal microbicide.