Oral Pre-Exposure Prophylaxis (PrEP) Awareness and Acceptability Among Persons who Inject Drugs (PWID) in Kenya: A Qualitative Investigation

Background: People who inject drugs (PWID) are disproportionately affected by HIV despite the availability of multiple efficacious biomedical prevention interventions including oral pre-exposure prophylaxis (PrEP). Little is known about the knowledge, acceptability, and uptake of oral PrEP among this population in Kenya. To inform the development of oral PrEP uptake optimization interventions for PWID in Kenya, we conducted a qualitative assessment to establish oral PrEP awareness and willingness to take PrEP by this group in Nairobi City. Methodology: Guided by the Capability, Opportunity, Motivation, and Behaviour (COM-B) model of health behavior change, we conducted 8 focus group discussions (FGDs) among randomly constituted samples of PWID in four harm reduction drop-in centers (DICs) in Nairobi in January 2022. The domains explored were: perceived risks (behaviour), oral PrEP awareness and knowledge (capability), motivation to use oral PrEP (behaviour), and perceptions on community uptake (motivation and opportunity). Completed FGD transcripts were uploaded to Atlas.ti version 9 and thematic analysis was conducted through an iterative process of review and discussion by two coders. Findings: There was a low level of oral PrEP awareness with only 4 of the 46 PWID having heard of PrEP; only 3 out of 46 participants had ever used oral PrEP and 2 out of 3 were no longer using it, indicating a low capacity to make decisions on oral PrEP. Most study participants were aware of the risk posed by unsafe drug injection and expressed willingness to take oral PrEP. Nearly all participants demonstrated low understanding of the role oral PrEP plays in complementing condoms in HIV prevention, presenting an opportunity for awareness creation. While the PWID were eager to learn more about oral PrEP, they favored DICs as places where they would like to obtain information and oral PrEP if they chose to use it, identifying an opportunity for oral PrEP programming interventions. Conclusion: Creation of oral PrEP awareness among PWID in Kenya is likely to improve uptake since the PWID are receptive. Oral PrEP should be offered as part of combination prevention approaches, and effective messaging through DICs, integrated outreaches, and social networks are recommended to mitigate displacement of other prevention and harm reduction practices by this population. Trial Registration: ClinicalTrials.gov Protocol Record STUDY0001370.

persist, including the need to improve PrEP access, optimal delivery models, training of health care workers, and retention into oral PrEP care. [32] For example, despite oral PrEP tablets collection by men who have sex with men (MSM) in Kenya, retention, and adherence to the same is low. [33] Thus, a scale-up of oral PrEP use among PWID guided by an understanding of speci c barriers faced by this group is therefore required. [23,34] To achieve sustainable control of HIV transmission among PWID and their partners, evidence-based HIV prevention strategies are required and this should be informed by existing service challenges and gaps. [35,36] For this reason, there is need to evaluate oral PrEP awareness and acceptability among PWID and their injecting and sexual partners in Kenya. [37,38] Additionally, key barriers such as user challenges, access, and adherence and effectiveness among PWID and their partners must be evaluated with an objective of adapting best delivery models, making social and behavioral impact and integration of oral PrEP services with other services targeting these population groups. [37,38] Whereas oral PrEP has been scaled up in Krenya's general population, gaps still exist among KPs including PWID. [39,40] In light of these contextual gaps, this study was aimed at investigating oral PrEP awareness and acceptability among PWID in Nairobi County to inform the development of oral PrEP interventions for PWID and their partners.

Methods
We used a theory-based model to understand oral PrEP awareness and acceptability among PWID in Nairobi with the objective of developing tailored interventions to promote oral PrEP uptake and adherence. As part of the formative process, we conducted a baseline assessment through focus group discussions (FGDs) whose development and analysis were guided by the Capability, Opportunity, Motivation and Behaviour (COM-B) model. [65,66] In brief, the COM-B model asserts that capability, opportunity, and motivation interact to generate behaviour. The single-headed and double-headed arrows in Fig. 1 below represent potential in uence between components in the system. The causal links within the system can work to reduce or amplify the effect of particular interventions by leading to changes. In our case, we were interested in what components of the behaviour system would need to be changed to achieve oral PrEP uptake (Fig. 1).
In January 2022 we conducted 8 FGDs among randomly constituted samples of HIV-negative PWID in Nairobi county recruited through peer educators (program staff providing day to day outreaches and awareness sessions on the harms of drugs injection, safe needle and syringe use and HIV infection prevention) working in four DICs through word of mouth. Eligible PWIDs were recruited to participate in the 8 FGDs that were strati ed by gender (one male and one female FGDs in each of the four drop-in centers). The overall goal was to assess oral PrEP awareness, experiences, acceptability, and strategies for optimizing uptake in this population. The FGDs were conducted by two female qualitative interviewers (both holding master's degrees in public health) who have previously worked with PWID and other KPs and interviews took place in DICs which are considered safe spaces for PWIDs and privacy was maintained.
Study inclusion criteria were age 18 years and above, self-identi cation as PWID, active injection in the preceding six months, no selfreported acute HIV infection or established HIV infection, and ability to consent to participation in the study.
Guided by the COM-B framework, we designed a semi-structured focus group interview guide to document oral PrEP awareness and acceptability among the PWID. The domains explored were: perceived risky behaviours which denote motivation under the COM-B framework, oral PrEP awareness, and knowledge which denote capability and opportunity under the COM-B model, and motivation to use oral PrEP and perceptions on community uptake which signify motivation and opportunity to take up oral PrEP under the COM-B model. FGD sessions lasted 80 to 100 minutes and were conducted in Swahili, audio-recorded then transcribed and translated to English. Each FGD participant was reimbursed transport costs at a uniform rate of 400 Kenya Shillings (4 USD). Written informed consent (Swahili and English versions) was given by all the FGD participants.
Completed FGD transcripts were uploaded to Atlas.ti version 9 for analysis. We selected 20% of transcripts to check for accuracy in comparison with their respective Swahili audio-les. An initial codebook was developed by two coders based on a subset of transcripts and literature review. Additional codes were those that emerged during the coding process and were included in the nal codebook. Using the nal codebook, all transcripts were coded by one coder and then coding reviewed by a second coder. Disagreements in coding were resolved through discussion. Using thematic analysis, themes were arrived at through an iterative process of review and discussion by the two coders.
Institutional Review Board (IRB) approval was obtained from the University of Washington's Human Subjects Division and the Kenyatta National Hospital (KNH)/University of Nairobi (UON) Ethical Review Committee, and a research permit was obtained from the National Commission for Science, Technology and Innovation (NACOSTI) in Kenya. All methods were performed in accordance with the relevant IRB guidelines and regulations.

Results
A total of 46 PWID participated in the eight FGDs in the four DICs (52.2% males and 47.3% females, Table 1). Most participants had a primary school level of education (82.4%) with only 17.6% having secondary school education level. In terms of livelihoods, 47.1% were casual labourers, 32.4% were engaged in sex work and 8.8% were self-employed while 11.8% had no source of income. The average monthly income was Kenya Shillings 0 to 5000 (0-50 USD) per month for 41.2% of the FGDs participants, KSHs 5000 to 10,000 (50-100 USD) per month for 47.1% of them and KSHs 10,000 to 20,000 (100-200 USD) per month for the remaining 11.8% (Table 1). The majority of participants (93.5%) in this study had never heard of oral PrEP. They were excited to learn about oral PrEP as expressed by the quote below. It was evident that this high-risk HIV group had limited access to health information and services since they largely lived in hideouts due to fears of stigma and discrimination, fear of law enforcement agencies, inconsistent access to information sources and unavailability of differentiated services targeting the group.
"I also had no idea of what PrEP is, I have heard about it today and I am happy I will know more about it from this forum. It will help us and we will help others." [FGD 1 participant, Male] It was evident that even after providing brief information on oral PrEP, some of the participants still did not understand basic aspects prompting facilitators to revisit the informational poster during the discussion. This low comprehension of the provided information re ects the low education levels among the PWID as illustrated in Table 1 and is also indicative of the need for simpli ed messages on PrEP targeting PWID.
"I have learned about PEP and PrEP today, just now. That's why you can see I have been silent because I don't understand." [FGD 2 participant, Female] A few participants reported that they had heard about or used oral PrEP but were confusing post-exposure prophylaxis (PEP) with oral PrEP. Given that awareness largely spread through networks, the confusion between PrEP and PEP indicates a lack of clarity between these two HIV prevention measures, demonstrating the need for targeted education and prevention efforts for PWID. Related to the aforementioned is the fact that, in Kenya, PEP was rolled out before PrEP hence a higher level of PEP awareness among key populations.
"Even when you are raped, you can also use PrEP." [FGD 4 participant, Female] "I have ever used it, when I was injecting, I noticed that the cotton wool that I was using had stains of human blood but since it was at night nothing much I would have done so I went to the hospital and was prescribed PrEP which I used for 28 days after which I went for a blood test which came out negative." [FGD 3 participant, Male] While some of the participants had heard of oral PrEP, they did not have any understanding of what it entailed and desired to gain understanding. This observation points to substantial unmet information needs due to the limited information available to the PWID.
"I have ever heard of PEP and PrEP but have never known the difference so it's good that you are here to expound more on it." [FGD 6 participant, Male] Given the lack of information on oral PrEP in this population and the enthusiasm to learn more, PWID had several questions about oral PrEP. Speci cally, eligibility criteria for PrEP use, use of PrEP concurrently with other medications, and places where the oral PrEP tablets could be obtained were enquiries from the FGD participants. It was evident that participants had misconceptions on how to correctly use oral PrEP and the timing and duration of taking PrEP drugs.
They perceived that oral PrEP was to be used right before a sexual encounter. Misinformation about this novel HIV preventative measure was evident and this has implications on impeding PrEP uptake. Therefore, the likely misinformation proliferation through shared opinions among peers featured strongly among participants.
"Before we thought you take PrEP right before sex, we didn't know how long to use it, or when to start. So, we have been enlightened. We could have made a mistake. But now we have been helped." [FGD 4 participant, Female] "I knew about it, what I didn't know is for how many hours you should take the drugs prior to having sex with your partner so that you cannot be at risk of getting infected. Participants further explained that female participants may be less likely to use condoms as they may be using other methods to prevent pregnancy and in case they contract STIs, they are con dent to receive treatment. Whereas STIs are one of the potential outcomes of sex that one would like to avoid, availablity of treatment for STIs and the knowledge that these infections were curable promoted unsafe sex in the group. Therefore, it was evident that interrupting transmission of infection, preventing re-infection and treating sexual partners was not only di cult in this group but also poorly understood. These perceptions may pose serious obstacles to STIs prevention efforts due to their in uence on social and sexual networks, access to and provision of care, willingness to seek care, and social norms regarding sex and sexuality. Misconceptions about STI risk and treatment necessitate accurate risk assessment and education and counseling regarding STI prevention through changes in sexual behaviors and use of the recommended prevention services. Recommended PrEP regimens do not appear to alter the effectiveness of hormonal contraceptives and the FGD participants noted that use of PrEP and contraceptives is likely to increase the dual protection from HIV and unwanted pregnancies.
"I think they should go hand in hand. I think PrEP can be used together with a condom." [FGD 7 participant, Male] Willingness to use Oral PrEP (Behaviour) Participants in this study expressed interest in using oral PrEP, driven by the perception of high risk for HIV due to sharing needles and equipment. Others added that they felt the need to protect themselves against HIV as they were at high risk due to engaging in sex work. This self-perception of being at high risk presents an opportunity for PrEP awareness creation and promotion among PWID. However, there were also a few participants who were not keen on using PrEP but were glad they were equipped with information to be able to decide if they got to a point they felt they needed PrEP. The quote below indicates that some PWID were happy to have learnt about PrEP but were not yet convinced to begin using it. Drop-in centers (DICs) are preferred as a source of information on oral PrEP and oral PrEP access. The participants mentioned other places such as government hospitals where their wider community can access oral PrEP and oral PrEP information but DICs were preferred over public facilities. Participants argued that it may be di cult for them to access information through other sources or media. DICs were preferred because of the privacy and safety attributed to these sites as well as the differentiated care and attention offered to the participants. Access to information from media and other community members was equally low due to economic barriers and social and security concerns that restrict their interactions with the general population.
"It may be di cult doing sensitization, it will depend on personal will but for us drug addicts, most of us come to DICs, so for us it will be easier for us here at the DIC. Speaking about us who engage in substance abuse, it's di cult to nd someone watching TV or reading a newspaper." [FGD 7 participant, Male] "I prefer DICs because most of us have no time to listen to radio or television and therefore almost 90% of us can gather rst-hand information from a DIC because it is where we even come to take our lunch, furthermore there is speci c information that one would want to hear and is not discussed either in radio or television so they are not reliable sources to get the information." [FGD 3 participant, Male] They also noted that it would be bene cial to have sensitization sessions on oral PrEP integrated in needle and syringe programs and targeted outreach programmes. This preference once again highlights privacy concerns and differentiated approaches for PrEP promotion in this population.
"I was thinking that those that come for the outreach to bring needles, could gather the men and talk to them. Not just bringing the needles and just leaving. At least talk to the men before they leave. Not everyone can afford the fare to come here, so, those that come to bring the needles could come with the kits for testing and then give the information [on PrEP].." [FGD 8 participant, Female] Participants also believed that oral PrEP could be bene cial if it was offered closer to them in the community. The quote below highlights the aforementioned confusion of PrEP for PEP. At the same time the aspect of travel distance to access PrEP is presented through preference for communal points for PrEP distribution and this may be attributed to privacy concerns and economic inaccessibility.
"Another thing, during sex not many people will be honest. After the sex is when you will come to realize you have been infected so oral PrEP will be good if they are available at the places we hang out. In case there comes someone to give out PrEP, it will be so good". [FGD 7 participant, Male] Oral PrEP availability will also enhance information reaching the intended population. Practical teachings with demonstrations as well as showcasing oral PrEP tablets would help clear some of the myths and misconceptions that PWID hold and also offer assurance that these drugs can be locally availed to those in need.
"One way to raise oral PrEP awareness is by teaching them and making PrEP available close to them. given that some of the PWID lived in the street while others had shared accommodation. Stigma from swallowing daily pills might therefore limit PrEP uptake among the PWID population.
"For us who abuse drugs, if we are given the PrEP to take home, we are prone to ignoring things and someone can easily ignore taking their drugs. So it will be better to use the drugs from here." [FGD 2 participant, Female] "For the con dentiality purpose one might prefer the monthly one because of avoiding being seen attending the center on either weekly or daily." [FGD 3 participant, Male]

Perceived Barriers to PrEP Use [Capability and Opportunity]
Three main perceived barriers to PrEP use were documented in the FGDs and these were the timing and frequency of swallowing PrEP, effects of missing out on daily doses, and accessing the distribution locations for PrEP pills. Mitigation of privacy-related barriers associated with daily oral PrEP use, the e cacy of PrEP, and ease in obtaining PrEP tablets and monthly re lls would therefore support opportunities for uptake, retention, and adherence to this biomedical intervention.
FGD moderator: What can be the challenges to using PrEP? were using oral PrEP including 6.0% in Nairobi. [41] The low oral PrEP awareness levels indicate may be a reason for the suboptimal uptake of this preventive innovation.
Although the Kenya national guidelines have recommended PrEP for individuals at substantial risk of HIV infection, its use remains low; indeed, among adolescent girls and young women seeking family planning services in clinics in parts of Western Kenya with high HIV prevalence, only 4.0% had ever taken up oral PrEP. [42,43] Similarly, among women living with HIV in Kenya in 2018, only 6.0% were aware of PrEP as a method for protecting HIV-uninfected partners from acquiring HIV. [44] Globally, low PrEP awareness and knowledge among PWID have been equally documented, with knowledge rates of 25% in Baltimore, 31.0% in New York, and 6.1% across twenty-two cities in India. [45,46] Overall, there is low use of PrEP in this group in qualitative studies in Bangkok as well as quantitative studies in the United States with studies showing that ≤1% of PWID in n Seattle, Washington were taking oral PrEP in 2021. [47,48] In addition, whereas PrEP is designed to be used in a planned way, on an ongoing basis and PEP is used in emergency situations, this distinction was not clear among the interviewed PWID. This nding has been documented among key populations in Portugal, Boston, Pittsburgh, San Juan and the northeastern region of the USA and it is attributed to low awareness of and exposure to these two interventions to these hidden population groups. [68,69,70] For all key populations, the World Health Organization (WHO) recommends offering oral PrEP to people at substantial risk of HIV infection, as part of combination prevention packages. The FGDs respondents have demonstrated a lack of clarity on the role oral PrEP plays as opposed to condom usage for HIV prevention. [49] Oral PrEP users in Kenya have previously expressed their confusion and frustration with health care providers' insistence on using condoms in addition to oral PrEP. [50] Previous studies among key populations on oral PrEP in Kenya have, however, shown increases in condom use from 6/10 to 9/10 in three months when the correct information is provided. [51] This calls for effective messaging to ensure the provision of oral PrEP while avoiding the displacement of existing condom use as guided by the World Health Organization. [52] Upon provision of brief information regarding oral PrEP by the research teams, most PWID were receptive to this intervention due to the perceived high risk of HIV infection from unsafe injection practices, involvement in sex work and sex outside sex work given the high prevalence among peers and partners, all of which have been previously documented. [53,54] The perception of high HIV risk in this group of PWID is an opportunity for potential behaviour change interventions to minimize or eliminate HIV transmission risks. Globally, willingness to take up oral PrEP upon awareness creation has been shown due to the perceived risk of HIV. This may indicate that awareness creation combined with existing risk perception can increase uptake of oral PrEP. [45] Multiple studies in USA have shown that increased awareness of PrEP was associated with higher willingness to use PrEP hence the need to ensure that PWID are knowledgeable about these pills. [55,56,57] Quantitatively, across various set ups including Canada and the United States, on average one in every three PWID expressed willingness to use PrEP. [56,58] The interviewed PWID indicated a preference of DICs for oral PrEP information and access, a nding that has been previously been documented among adolescents in Kenya who opted for the safe space model due to the privacy that comes with such settings. [59] This preference of DICs for information access offers an opportunity to provide behaviour change communication targeting PrEP uptake. As of 2017, 72% of the PWID in Kenya had visited a DIC including 75% of those in Nairobi, a further a rmation that these sites are popular among members of this vulnerable group. [60] In the country, PWIDs have cited nancial barriers to making visits to health centers, long distance to clinic and stigma as some of the reasons why they prefer DICs to health facilities for HIV services. [61] In other settings, negative experiences with healthcare providers, stigma within social networks, poor infrastructure and low capacity for PrEP delivery in health facilities have been proven to be barriers to PrEP uptake among PWID. [56] Lastly, sensitization sessions on oral PrEP integrated in DICs and outreach activities have also been reported by these FGD participants as a suitable platform to create awareness on oral PrEP. The recommended use of outreach activities conducted by NSPs where peers can sensitize clients in the community presents an opportunity for oral PrEP awareness creation. Social networks that have the potential to motivate PWIDs can also be leveraged to increase uptake of oral PrEP, promote adherence and improve retention in this vulnerable population. This nding indicates that social networks and peer led outreaches within the larger NSPs may be e cient means for disseminating messaging about oral PrEP. [62,63,64] Limitations Informed consent was obtained from the study participants, written informed consent (Swahili and English versions) was given by all the FGD participants and the study team ensured adherence to a high standard (best practice) of experimental studies and the safety of PWIDs. All methods were performed in accordance with the relevant IRB guidelines and regulations.

Consent for publication
Not applicable.

Availability of Data and Materials
All the data collection tools and data are in the custody of Dr. Cosmas Mugambi and are available on request.

Competing interests
The authors declare that they have no competing interests. The study was also supported by a US National Institutes of Health (NIH) National Institute on Drug Abuse (NIDA) funded study (R01 DA043409). The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the o cial views of the National Institutes of Health.

Authors Contributions
All the nine authors (GCM, AM-W, JK, TT, LM, CF, WS, EG, and DB) made substantial contributions to the conception and design of the study, acquisition of data, analysis, and interpretation of data; and they have been involved in drafting the manuscript or revising it critically for important intellectual content, and they have given nal approval of the version to be published, and they have agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. COM-B model [65,66]