Abstract Background The relationship between HIV serostatus disclosure and sexual risk behavior is inconsistent across studies. As men who have sex with men (MSM) are emerging as the key affected population in Bangkok, Thailand with reported HIV prevalence of 30%, we assessed whether HIV disclosure is associated with protected sex in this population. Methods A risk behavior questionnaire was administered using Audio Computer-Assisted Self-Interviewing (ACASI) to determine whether HIV serostatus disclosure was associated with protected sex in 200 HIV-positive MSM in Bangkok. HIV serostatus disclosure to the most recent sexual partner prior to or at the time of the sexual encounter was assessed. Protected sex was defined as insertive or receptive anal intercourse with a condom at the most recent sexual encounter. Results The mean age was 30.2 years, CD4 was 353 cells/mm3, and one-third was on antiretroviral therapy. At the most recent sexual encounter, HIV serostatus disclosure rate was low (26%); 60.5% of subjects had not discussed their serostatus at all, while 5.5% had not revealed their true serostatus. Seventeen percent reported unprotected anal intercourse and about half had sex with their primary partners. The serostatus of the most recent sexual partner was HIV-positive in 19.2%, HIV-negative in 26.4%, and unknown in 54.4% of subjects. There was no association between disclosure and protected sex, with 41 of 48 (85.4%) disclosers and 104 of 126 (82.5%) of non-disclosers reported protected sex (p = .65). Subjects with HIV-positive partners were less likely to report protected sex overall (20 of 33, 60.6%) compared to those with HIV negative (82 of 96, 85.4%) or unknown (41 of 45, 91.1%) partners (p = .001). Age (27-32 years vs. ≤26 years, p = .008), primary partner status (p < .001), and HIV-positive serostatus of sexual partner (p < .001) were significantly associated with disclosure in the multivariate analyses. Conclusion Rates of HIV disclosure to sexual partners by HIV-positive MSM in Bangkok are low. Despite low rates of HIV serostatus disclosure, most HIV-positive MSM reported protected sex with their partners at risk for infection. Future studies should focus on understanding barriers to disclosure and factors driving risk behavior amongst MSM in Thailand.

Background

Black men who have sex with men (MSM) have a high prevalence of bacterial sexually transmitted infections (STIs), and individual risk behavior does not fully explain the higher prevalence when compared with other MSM. Using the social-ecological framework, we evaluated individual, social and sexual network, and structural factors and their association with prevalent STIs among Black MSM.

Methods

The HIV Prevention Trials Network 061 was a multi-site cohort study designed to determine the feasibility and acceptability of a multi-component intervention for Black MSM in six US cities. Baseline assessments included demographics, risk behavior, and social and sexual network questions collected information about the size, nature and connectedness of their sexual network. Logistic regression was used to estimate the odds of having any prevalent sexually transmitted infection (gonorrhea, chlamydia, or syphilis).

Results

A total of 1,553 Black MSM were enrolled in this study. In multivariate analysis, older age (aOR = 0.57; 95% CI 0.49-0.66, p<0.001) was associated with a lower odds of having a prevalent STI. Compared with reporting one male sexual partner, having 2-3 partners (aOR = 1.74; 95% CI 1.08-2.81, p<0.024) or more than 4 partners (aOR = 2.29; 95% CI 1.43-3.66, p<0.001) was associated with prevalent STIs. Having both Black and non-Black sexual partners (aOR = 0.67; 95% CI 0.45-0.99, p = 0.042) was the only sexual network factor associated with prevalent STIs.

Conclusions

Age and the number and racial composition of sexual partners were associated with prevalent STIs among Black MSM, while other sexual network factors were not. Further studies are needed to evaluate the effects of the individual, network, and structural factors on prevalent STIs among Black MSM to inform combination interventions to reduce STIs among these men.

Accurate HIV risk assessment among men who have sex with men (MSM) is important to help providers assess risk, and target HIV prevention interventions. We sought to develop an evidence-based HIV risk assessment tool for US MSM that is inclusive of Black MSM. Data from four large longitudinal cohorts of MSM were used to develop (EXPLORE), and validate (VAX004, HPTN061, and HVTN505). These data included visits in which participants self-reported HIV risk behavior and underwent HIV testing. We developed a pooled logistic model for incident HIV infection based on self-reported risk behaviors during the 6 months before each study visit. A total of 4069 MSM were used for the development cohort, and 8047 MSM in the three validation cohorts through 2013. The final model includes age (< 35, ≥ 35); Black race and Latino ethnicity; numbers of HIV-negative anal sex partners; number of insertive or receptive anal intercourse episodes; having 1 HIV-negative partner only; self-reported substance use; and bacterial sexually transmitted infection diagnosis. The model showed good discrimination in internal validation (C-statistic = 79.5). The external validation cohorts also showed good discrimination, with C-statistics of 73.1, 71.0, 71.9 in VAX004, HPTN061, and HVTN505 respectively, and acceptable calibration. We developed and validated an HIV risk assessment tool for MSM, which showed good predictive ability, including among the largest cohort of HIV-uninfected Black MSM in the US. This tool is available online (mysexpro.org) and can be used by providers to support targeting of HIV prevention interventions such as pre-exposure prophylaxis for MSM.

T cell responses have been implicated in reduced risk of HIV acquisition in uninfected persons and control of viral replication in HIV-infected individuals. HIV Gag-specific T cells have been predominantly associated with post-infection control, whereas Env antigens are the target for protective antibodies; therefore, inclusion of both antigens is common in HIV vaccine design. However, inclusion of multiple antigens may provoke antigenic competition, reducing the potential effectiveness of the vaccine. HVTN 084 was a randomized, multicenter, double-blind phase 1 trial to investigate whether adding Env to a Gag/Pol vaccine decreases the magnitude or breadth of Gag/Pol-specific T cell responses. Fifty volunteers each received one intramuscular injection of 1 × 1010 particle units (PU) of rAd5 Gag/Pol and EnvA/B/C (3:1:1:1 mixture) or 5 × 109 PU of rAd5 Gag/Pol. CD4+ T cell responses to Gag/Pol measured 4 weeks after vaccination by cytokine expression were significantly higher in the group vaccinated without Env, whereas CD8+ T cell responses did not differ significantly between the two groups. Mapping of individual epitopes revealed greater breadth of the Gag/Pol-specific T cell response in the absence of Env compared to Env coimmunization. Addition of an Env component to a Gag/Pol vaccine led to reduced Gag/Pol CD4+ T cell response rate and magnitude as well as reduced epitope breadth, confirming the presence of antigenic competition. Therefore, T cell-based vaccine strategies should aim at choosing a minimalist set of antigens to reduce interference of individual vaccine components with the induction of the maximally achievable immune response.

Background

Elicitation of broad immune responses is understood to be required for an efficacious preventative HIV vaccine. This Phase 1 randomized controlled trial evaluated whether administration of vaccine antigens separated at multiple injection sites vs combined, fractional delivery at multiple sites affected T-cell breadth compared to standard, single site vaccination.

Methods

We randomized 90 participants to receive recombinant adenovirus 5 (rAd5) vector with HIV inserts gag, pol and env via three different strategies. The Standard group received vaccine at a single anatomic site (n = 30) compared to two polytopic (multisite) vaccination groups: Separated (n = 30), where antigens were separately administered to four anatomical sites, and Fractioned (n = 30), where fractions of each vaccine component were combined and administered at four sites. All groups received the same total dose of vaccine.

Findings

CD8 T-cell response rates and magnitudes were significantly higher in the Fractioned group than Standard for several antigen pools tested. CD4 T-cell response magnitudes to Pol were higher in the Separated than Standard group. T-cell epitope mapping demonstrated greatest breadth in the Fractioned group (median 8.0 vs 2.5 for Standard, Wilcoxon p = 0.03; not significant after multiplicity adjustment for co-primary endpoints). IgG binding antibody response rates to Env were higher in the Standard and Fractioned groups vs Separated group.

Interpretation

This study shows that the number of anatomic sites for which a vaccine is delivered and distribution of its antigenic components influences immune responses in humans.

Funding

National Institute of Allergy and Infectious Diseases, NIH.

Background

The HIV Prevention Trials Network (HPTN) 083 trial showed that long-acting injectable cabotegravir was more effective than tenofovir disoproxil fumarate plus emtricitabine in preventing HIV in cisgender men and transgender women who have sex with men. We aimed to characterise the cohort of transgender women included in HPTN 083.

Methods

HPTN 083 is an ongoing, phase 2b/3, randomised, multicentre, double-blind, double-dummy clinical trial done at 43 sites in seven countries (Argentina, Brazil, Peru, the USA, South Africa, Thailand, and Viet Nam). HIV-negative participants were randomly assigned (1:1) to receive injectable cabotegravir or tenofovir disoproxil fumarate plus emtricitabine. The study design and primary outcomes of the blinded phase of HPTN 083 have already been reported. An enrolment minimum of 10% transgender women was set for the trial. Here we characterise the cohort of transgender women enrolled from Dec 6, 2016, to May 14, 2020, when the study was unblinded. We report sociodemographic characteristics, use of gender affirming hormone therapy, and behavioural assessments of the transgender women participants. Laboratory testing and safety evaluations are also reported. The trial is registered at ClinicalTrials.gov, NCT02720094.

Findings

HPTN 083 enrolled 570 transgender women (304 tenofovir disoproxil fumarate plus emtricitabine; 266 injectable cabotegravir). Transgender women were primarily from Asia (225 [39%]) and Latin America (205 [36%]); 330 (58%) reported using gender affirming hormone therapy. Intimate partner violence was common (270 [47%] reported emotional abuse and 172 [30%] reported physical abuse) and 323 (57%) reported a history of childhood sexual abuse. 159 (28%) transgender women disagreed that they were at risk for HIV, and 142 (25%) screened positive for depressive symptoms. During study follow-up, incidence of syphilis was 16·25% (95% CI 13·28-19·69), rectal gonorrhoea was 11·66% (9·14-14·66), and chlamydia was 20·61% (17·20-24·49). Frequency of adverse events was similar between the treatment groups. Nine seroconversions occurred among transgender women during the blinded phase of the study (seven in the tenofovir disoproxil fumarate plus emtricitabine group and two in the injectable cabotegravir group); overall incidence was 1·19 per 100 person-years (95% CI 0·54-2·25): 1·80 per 100 person-years (0·73-3·72) in the tenofovir disoproxil fumarate plus emtricitabine group and 0·54 per 100 person-years (0·07-1·95) in the injectable cabotegravir group (hazard ratio 0·34 [95% CI 0·08-1·56]). Cabotegravir concentrations did not differ by gender affirming hormone therapy use.

Interpretation

HIV prevention strategies for transgender women cannot be addressed separately from social and structural vulnerabilities. Transgender women were well represented in HPTN 083 and should continue to be prioritised in HIV prevention studies. Our results suggest that injectable cabotegravir is a safe and effective pre-exposure prophylaxis option for transgender women.

Funding

National Institute of Allergy and Infectious Diseases and ViiV Healthcare.