In this qualitative investigation among diverse subpopulations of MSM in two large Indian cities, decision-making about WTP was embedded in social-structural, community and familial spheres of influence. By focusing on WTP among MSM in India at the individual level we risk not only misunderstanding and misconceptualizing barriers and motivators to WTP; but we may fail to mitigate ethical challenges as well as circumscribe the impact of interventions designed to support recruitment and retention in biomedical HIV prevention trials.
The preponderance of studies of WTP tend to consider the individual as the foundation for decision-making 
, perhaps reflecting the influence of Western psychology and the dominance of individualism. The crucial role of the global south–with the greatest burden of HIV and availability of cohorts with HIV incidence to power cost-effective HIV prevention trials–suggests the value of adopting a social ecological approach in WTP research and formative HIV vaccine preparedness interventions. For one, conceptualizations of HIV, vaccines and clinical trials are rooted in the sociocultural context 
. Secondly, as in the present study, although important individual-level concerns are evident, they are embedded in broader familial, community and structural domains.
is a conceptual model of emergent themes in WTP, organized at social-structural, community, interpersonal and individual levels. As indicated in , apparently individual-level decisions to participate or not are influenced by social stigma and institutionalized discrimination against same-sex sexuality, gender nonconformity and people living with HIV, and government endorsement of clinical trials (social-structural); endorsements by MSM community leaders and CBOs, peers and past trial participants (community level); and extensive considerations about familial relationships–with parents, male partners and female spouses (interpersonal level). Many of these factors are manifested at multiple levels of the individual’s social ecology.
Figure 1 A social ecological model of willingness to participate in HIV vaccine trials among MSM in Chennai and Mumbai, India (n=82).
Stigma and discrimination permeated the social ecology of WTP among MSM. Although the Delhi high court in 2008 
decreed that consensual sex between same-sex adults is no longer criminal, participants were concerned about prevailing negative and sometime hostile societal attitudes and institutionalized discrimination against same-sex attracted people, particularly those who are not gender-conforming 
. Stigma operated at the community level in expressed fears of being looked down upon by one’s peers–including other MSM–as one who engages in sexual risk behaviors or is HIV-positive, and thereby one who may fuel stereotypes about MSM among the general public.
At the interpersonal level, stigma operated through fears of adverse consequences of unwanted disclosure of one’s sexuality, including family rejection (from parents, female spouses and male partners) and loss of respect and bringing shame upon one’s family. Accordingly, the stigma that permeates the social ecology of many MSM in India may effectively transform their widespread motivations based on altruism and wanting to give back to their community into liabilities.
In light of the lack of mention of family in most existing studies of WTP, the role of families in decision-making was notable. In a review of 53 HIV vaccine preparedness studies 
, only one, conducted among heterosexuals in India, noted social costs due to familial concerns 
. In the present study, MSM described consulting with and even getting ‘permission’ from parents and partners as essential to WTP. Interestingly, MSM who were financially dependent on parents feared being cut off; and MSM whose parents were financially dependent on them feared becoming ill or injured from the trial and not being able to provide for the family. In both cases financial considerations implicate the centrality of family to WTP. MSM who did not live with their parents and were unmarried expressed reliance on the advice of community leaders and CBO staff, a type of surrogate family–and high WTP contingent on CBO endorsement.
Another pervasive concern was the safety and potential side effects of experimental HIV vaccines, as corroborated by many studies of WTP 
. Some participants understood the inherent uncertainty of clinical trials as well as the fact that a phase III trial indicated previous testing for product safety. However some MSM demanded decisive assurances that there would be no
adverse effects. Safety concerns, however, which are generally approached as an individual-level phenomenon and might thereby be addressed by trialists through educational measures and the informed consent process, were embedded in familial concerns. Many MSM expressed WTP contingent on clinical trials providing health insurance coverage and compensation for family members in the event they are injured in a trial.
Competing considerations about monetary compensation emerged among MSM participants and community leaders. Participants expected that trial volunteers should be well compensated for their time. However, MSM CBO leaders were acutely aware of the potential for compensation that is tantamount to coercion among a client population in which most earn less than $1.50 US per day 
, half of per capita Indian income (~$3.00 US per day) 
. Although MSM community leaders largely supported WTP, recognizing the importance of an HIV vaccine to their communities, they were adamant that participation be truly informed and voluntary. Similar concerns about the role of financial incentives in WTP have been expressed in other low- and middle-income country sites in Africa 
and among marginalized populations in the US 
Importantly, preventive misconception emerged across focus group participants and KIs, along with misunderstanding of key clinical trial concepts, even among those MSM previously engaged in IAVI consultations. Some participants failed to understand the meaning of “candidate” or “experimental”–that the product being tested might not be efficacious; among these, some MSM further construed clinical trials as a form of preventive intervention. Why would a trusted CBO refer them if the “intervention” was not effective? Others, while grasping the experimental nature of vaccines tested in clinical trials, failed to comprehend the meaning of placebo-controlled; they presumed that they, like everyone else, would be given the experimental vaccine, thereby enabling hope that it might work. Finally, others comprehended the meaning of experimental vaccines and placebo-controlled trials, but retained hope that they might be “lucky” and gain protection. In each of these cases the potential for increased sexual risk behaviors arose, including the ability to engage in sex work to generate income without HIV risk.
Misconceptions about HIV vaccine trials may be due in part to the fact that some key clinical trial terminology does not directly translate into Tamil or other Indian languages; and the literal or scientific translation is not comprehensible to lay participants with high school education or less who do not understand the scientific basis for randomized controlled trials (RCTs). A prominent example is “placebo”. A KI community leader who had been engaged in previous IAVI consultations noted that he did not adequately understand what “placebo” means and was unable to explain it to peer outreach staff or clients. Some participants concretely adopted the term “distilled water” as a synonym; however they went on explain that it was unfair to give some trial participants distilled water instead of the test vaccine (which, they reasoned, might be efficacious) and, moreover, unfair and unacceptable that participants would be blind to their randomization.
A second reason for misconceptions may be due to misinterpretation, or perhaps over-interpretation, of clinical trial guidelines in the absence of an understanding of the scientific (and ethical) basis for RCTs. Some MSM peer outreach workers in focus groups (who regularly interact with MSM clientele) indicated beliefs that MSM in trials should abstain from sex (as it might be made more dangerous by the experimental product), while others indicated that MSM in clinical trials should not use condoms so the efficacy of the experimental vaccine could be determined. A third possible basis for misconceptions about HIV vaccine trials is misunderstanding and folk theories about HIV transmission 
and HIV vaccines 
. For example, the mental model of vaccines as introducing a small dose of pathogen to train the immune system 
–and fear that inactivated HIV may “come alive” when it comes into contact with blood–is particularly troublesome in the case of HIV.
Finally, varying perspectives emerged on WTP across different MSM subgroups. Most indicated that kothis, particularly kothis engaged in sex work, would be more likely to participate compared to double-deckers or panthis; kothis have a strong sense of community identity, are attached to MSM CBOs and often live in poverty. However, panthis and double-deckers indicated that MSM from their groups are not preoccupied by fears of disclosure of their sexuality as most are masculine-looking and perceived to be ‘heterosexual’; thus stigma may be less of a barrier to participation than among kothis. Focus group participants and KIs alike indicated that middle- and upper-class MSM, even those who self-identify as gay or bisexual, would be less likely to participate; many do not perceive themselves or their community to be at risk for HIV, they largely do not engage with MSM CBOs (generally serving lower socioeconomic MSM) and the compensation would be negligible.
As a qualitative study, our purpose was to explore in depth rather than to generalize; thus the findings may not apply across MSM populations in India. In particular, the sample may be more representative of lower socioeconomic MSM; middle- and upper-class MSM in India may have different perspectives on WTP. Additionally, the recruitment methods may bias the sample towards MSM who are already engaged with CBOs. MSM who are not connected with CBOs may prove harder to reach, less aware about HIV and less willing to participate. However we successfully recruited a moderately sized and diverse sample of MSM, community leaders and service providers across four languages in two large metropolitan areas in India with high HIV prevalence among MSM–feasible locales for conducting biomedical HIV prevention trials.
Implications for Practice and Research
Implications of the social ecology of WTP among MSM in India are that trialists approach at multiple levels what might otherwise be construed largely as individual-level phenomena (e.g., side effects, safety, monetary compensation and altruism)–and thereby largely addressed with interventions targeting the individual. For example, knowledge-based approaches to address misconceptions and mitigate undue fears of side effects and safety concerns may be ineffective in supporting WTP if they do not address financial considerations regarding lost income and support for dependent family members. Societal and community stigma and familial relationships provide a crucial lens for understanding WTP among MSM in India; they also underscore the importance of confidentiality 
and respectful relationships between trial staff and participants 
in supporting WTP as well as retention in HIV prevention trials.
Measures at the social-structural level to reduce barriers to WTP among MSM might include mass media campaigns that aim to promote positive images of same-sex sexuality and destigmatize HIV. The Indian government has previously launched a television and billboard advertising campaign that mobilized a popular cartoon character with a play on words (in Tamil) to challenge the image of a man with many female sex partners as virile, instead designating the character as foolish and at high risk for HIV. Similar campaigns might target negative attitudes among the general public towards MSM and persons living with HIV.
At the community level, tailored interventions to reduce HIV stigma among MSM also may support WTP. Although preventive HIV vaccine trials require participants to be HIV negative, merely engaging with a trial engenders suspicions that one is HIV positive or at high risk, thereby inviting stigma within MSM communities. CBO engagement in promoting positive images of MSM who are willing to volunteer for HIV vaccine trials may help to mobilize motivations for WTP based on altruism and giving back to one’s community, as well as combat stigma 
At the interpersonal level, recognizing the importance of family and partner dynamics among MSM to WTP, potential volunteers might be offered voluntary opportunities to engage their male partner, either separately or as a couple, to meet with a trained trial educator or counselor to address concerns about participation. Similarly, clinical trial staff and MSM outreach workers might be trained to counsel families about their concerns if individual participants so desire.
Given the prevalence of HIV vaccine trial misconceptions and the challenges of explaining basic concepts of RCTs to individuals with low education in the context of folk beliefs about HIV, a mental models approach 
might be incorporated in future community consultation meetings with MSM in India. At the individual level, new knowledge may be more successfully integrated if it is layered onto one’s existing conceptualizations 
. In our previous qualitative research among MSM in Chennai, for example, we identified a mental model deployed by peer educators to explain how antiretroviral medications work, using the metaphor of an egg 
. HIV was described as entering the body’s cells and laying many eggs, akin to a mosquito with which participants are familiar. Antiretrovirals were described as preventing those eggs from hatching and baby viruses from being released. Mental models have been similarly used to support HIV prevention in Kenya, an agricultural country, invoking “zero-grazing” to signify faithfulness to one or even multiple partners within the context of monogamous or polygamous relationships 
. It is important, however, that such mental models are founded on in depth cultural understanding and formative qualitative research conducted in situ, and deployed cautiously; they have the potential to be infused with existing folks beliefs, resulting in further misinformation rather than clarification 
Further research among MSM in India may help to prioritize the most influential factors across the social ecology of WTP as well as to explore subpopulation differences–by geography, socioeconomic status and self-identified sexuality (e.g., kothi, panthi, double-decker, gay)–to support tailored community education and recruitment efforts. Conducting recruitment solely through MSM CBOs, however, may tend primarily to reach kothis, particularly those who engage in sex work, and may be less likely to reach middle-class gay- and bisexually-identified MSM.
This investigation among diverse MSM in India suggests that applying a social ecological approach to WTP may enhance the success of recruitment efforts and the ethical implementation of HIV vaccine trials. To that end, with a new HIV vaccine design program collaboration in India 
and phase II trials under consideration, this community-based investigation supports the value of the process of trialists partnering with local CBOs that work with MSM in designing and implementing study protocols, and involving community advisory boards and other local stakeholders throughout the trial trajectory.