Willingness to volunteer in a Phase I/II HIV vaccine trial: a study among police officers in Dar es Salaam, Tanzania

Tarimo, Edith A. M.; Thorson, Anna; Bakari, Muhammad; Mwami, Joachim; Sandström, Eric; Kulane, Asli

doi:10.3402/gha.v2i0.1953

Cited by 17 publications

(30 citation statements)

References 23 publications

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“…Among men, the most important motivators for trial participation were social benefits, as has been reported by others (Jenkins et al 2000, Strauss et al 2001, Newman et al 2006, Tarimo et al 2009). A few personal risks (most notably receiving injections and/or blood draws) were negatively associated with WTP.…”

Section: Discussionmentioning

confidence: 70%

“…The male university students were the least interested in participating and reported the lowest risk-taking behaviour. They may have perceived themselves to be at low risk of HIV, and low perception of risk has been associated with lower WTP worldwide (Jenkins et al 2000, Mills et al 2004, Tarimo et al 2009). These WTP differences by gender and educational level were not found in other settings (de Bruyn 200, Middelkoop et al 2008).…”

Section: Discussionmentioning

confidence: 98%

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Willingness to participate in future HIV prevention trials in Beira, Mozambique

Meque

Dubé

Bierhuizen

et al. 2014

African Journal of AIDS Research

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In preparation for trials of new HIV prevention methods, willingness to participate (WTP) was assessed in Beira, Mozambique. A total of 1 019 women participating in an HIV incidence study, and 97 men participating in a separate WTP survey, were interviewed. When comparing the answers to questions that were identical in the two studies, WTP was higher among women than men for all prevention methods. Among women, WTP was highest for trials evaluating daily oral pre-exposure prophylaxis (PrEP; 84.4% reporting very likely to participate), followed by vaccination (77.8%), daily vaginal gel use (67.7%), coital vaginal gel use (67.1%) and monthly vaginal ring use (47.7%). Among men, WTP was highest for trials evaluating vaccination (57.6%), followed by daily vaginal gel use for female sexual partners (52.5%), daily oral PrEP (49.5%), coital vaginal gel use for female sexual partners (46.4%) and monthly vaginal ring use for female sexual partners (39.4%). Among men, the most important motivators for trial participation were social benefits, whereas personal risks (most notably receiving injections and/or blood draws) were deterrents; this was not assessed in women. Other important lessons learnt are that male circumcision and antiretroviral drugs were not generally recognised as ways to prevent HIV, that having to use hormonal contraception during trial participation will likely reduce WTP, and that evening clinics are not likely to be popular. The barriers reported in this and other studies may be challenging but are not impossible to overcome.

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Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 98%

Willingness to participate in future HIV prevention trials in Beira, Mozambique

Meque

Dubé

Bierhuizen

et al. 2014

African Journal of AIDS Research

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“…Volunteers from the Police Force were chosen for this study because this highly organized institution favoured the probability of long-term follow-up [56]. Their participation was purely altruistic and voluntary.…”

Section: Discussionmentioning

confidence: 99%

Broad and potent immune responses to a low dose intradermal HIV-1 DNA boosted with HIV-1 recombinant MVA among healthy adults in Tanzania

Bakari

Aboud

Nilsson

et al. 2011

Vaccine

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123

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Background We conducted a phase I/II randomized placebo-controlled trial with the aim of exploring whether priming with a low intradermal dose of a multiclade, multigene HIV-1 DNA vaccine could improve the immunogenicity of the same vaccine given intramuscularly prior to boosting with a heterologous HIV-1 MVA among healthy adults in Dar es Salaam, Tanzania. Methods Sixty HIV-uninfected volunteers were randomized to receive DNA plasmid vaccine 1 mg intradermally (id), n = 20, or 3.8 mg intramuscularly (im), n = 20, or placebo, n = 20, using a needle-free injection device. DNA plasmids encoding HIV-1 genes gp160 subtype A, B, C; rev B; p17/p24 gag A, B and Rtmut B were given at weeks 0, 4 and 12. Recombinant MVA (108 pfu) expressing HIV-1 Env, Gag, Pol of CRF01_AE or placebo was administered im at month 9 and 21. Results The vaccines were well tolerated. Two weeks after the third HIV-DNA injection, 22/38 (58%) vaccinees had IFN-γ ELISpot responses to Gag. Two weeks after the first HIV-MVA boost all 35 (100%) vaccinees responded to Gag and 31 (89%) to Env. Two to four weeks after the second HIV-MVA boost, 28/29 (97%) vaccinees had IFN-γ ELISpot responses, 27 (93%) to Gag and 23 (79%) to Env. The id-primed recipients had significantly higher responses to Env than im recipients. Intracellular cytokine staining for Gag-specific IFN-γ/IL-2 production showed both CD8+ and CD4+ T cell responses. All vaccinees had HIV-specific lymphoproliferative responses. All vaccinees reacted in diagnostic HIV serological tests and 26/29 (90%) had antibodies against gp160 after the second HIV-MVA boost. Furthermore, while all of 29 vaccinee sera were negative for neutralizing antibodies against clade B, C and CRF01 AE pseudoviruses in the TZM-bl neutralization assay, in a PBMC assay, the response rate ranged from 31% to 83% positives, depending upon the clade B or CRF01_AE virus tested. This vaccine approach is safe and highly immunogenic. Low dose, id HIV-DNA priming elicited higher and broader cell-mediated immune responses to Env after HIV-MVA boost compared to a higher HIV-DNA priming dose given im. Three HIV-DNA priming immunizations followed by two HIV-MVA boosts efficiently induced Env-antibody responses.

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“…The current result suggests that prolonged follow up counselling is useful towards such a significant decrease in number of volunteers who reported to have had extra sexual partners during the second follow up. A previous study in the same HIVIS03 vaccine trial population showed that a majority (58.2%) of study subjects were having a regular sexual partner, other than wife/husband [19]. Nevertheless, volunteers in the HIVIS 03 trial were assessed and categorized as a low risk group for acquiring HIV infection; this was proven true in the follow up results as all the volunteers who had received all the five doses of candidate vaccine products were confirmed by HIV-1 DNA PCR assay to be HIV-uninfected about two years after the second HIV MVA boost (un published data).…”

Section: Discussionmentioning

confidence: 92%

Experiences of Social Harm and Changes in Sexual Practices among Volunteers Who Had Completed a Phase I/II HIV Vaccine Trial Employing HIV-1 DNA Priming and HIV-1 MVA Boosting in Dar es Salaam, Tanzania

et al. 2014

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BackgroundVolunteers in phase I/II HIV vaccine trials are assumed to be at low risk of acquiring HIV infection and are expected to have normal lives in the community. However, during participation in the trials, volunteers may encounter social harm and changes in their sexual behaviours. The current study aimed to study persistence of social harm and changes in sexual practices over time among phase I/II HIV vaccine immunogenicity (HIVIS03) trial volunteers in Dar es Salaam, Tanzania.Methods and ResultsA descriptive prospective cohort study was conducted among 33 out of 60 volunteers of HIVIS03 trial in Dar es Salaam, Tanzania, who had received three HIV-1 DNA injections boosted with two HIV-1 MVA doses. A structured interview was administered to collect data. Analysis was carried out using SPSS and McNemars’ chi-square (χ2) was used to test the association within-subjects. Participants reported experiencing negative comments from their colleagues about the trial; but such comments were less severe during the second follow up visits (χ2 = 8.72; P<0.001). Most of the comments were associated with discrimination (χ2 = 26.72; P<0.001), stigma (χ2 = 6.06; P<0.05), and mistrust towards the HIV vaccine trial (χ2 = 4.9; P<0.05). Having a regular sexual partner other than spouse or cohabitant declined over the two follow-up periods (χ2 = 4.45; P<0.05).ConclusionParticipants in the phase I/II HIV vaccine trial were likely to face negative comments from relatives and colleagues after the end of the trial, but those comments decreased over time. In this study, the inherent sexual practice of having extra sexual partners other than spouse declined over time. Therefore, prolonged counselling and support appears important to minimize risky sexual behaviour among volunteers after participation in HIV Vaccine trials.

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Willingness to volunteer in a Phase I/II HIV vaccine trial: a study among police officers in Dar es Salaam, Tanzania

Cited by 17 publications

References 23 publications

Willingness to participate in future HIV prevention trials in Beira, Mozambique

Willingness to participate in future HIV prevention trials in Beira, Mozambique

Broad and potent immune responses to a low dose intradermal HIV-1 DNA boosted with HIV-1 recombinant MVA among healthy adults in Tanzania

Experiences of Social Harm and Changes in Sexual Practices among Volunteers Who Had Completed a Phase I/II HIV Vaccine Trial Employing HIV-1 DNA Priming and HIV-1 MVA Boosting in Dar es Salaam, Tanzania

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