Adolescents and young people living with HIV (AYPLHIV) account for 45% of new HIV infections globally, with 70% of this population residing in sub-Saharan Africa. In Sub-Saharan Africa (SSA), 37% of youth living with HIV/AIDS (YLHIVA) on antiretroviral therapy (ART) have viral load suppression (VLS). This is way below the UNAIDS target of 95% VLS. VLS reduces mortality rate and the risk of HIV transmission. In Uganda, only 44.9% of female and 32.5% male youth aged 15 to 24 years have VLS. ART adherence is essential in achieving VLS. However, in Uganda, ART adherence is suboptimal among the youth (67% -87%) and is lower compared to other age groups.

The sub-optimal ART adherence among YLHIVA result from complex personal, interpersonal, and contextual challenges. Among these challenges are the psychosocial barriers exacerbated by the social cognitive development changes that occur during adolescence and young adulthood. Social acceptance is more critical for this age group than any other, yet many YLHIVA experience stigma and bulling, leading to negative self-images, low self-efficacy, anxiety and depression. Depressed YLHIVA are more likely to abuse alcohol and drugs. World Health Organisation (WHO) and Ministry Of Health Uganda (MoH) recommend peer support groups to offer psychosocial support to YLHIVA. However, in Uganda and most Sub-Saharan countries, peer support group activities occur face-to-face and often in health facilities . This approach presents structural limitations such as the need to travel, inconvenient working hours and inadequate safe space for psychosocial services. The ongoing COVID-19 pandemic has worsened this situation; social distancing requires more space and curfew hours limit the time for providing psychosocial services. Thus, these psychosocial services may not be available at the time when youth need them and hence the need for more real-time and widely feasible interventions.

With the rapid increase in mobile phone availability in SSA, online peer support groups have the potential to help YLHIVA access regular support without significant effort or cost . In Uganda, 60.7% of youth own a mobile phone, 90% use their phone to call, 87.9% use them for social media and 64% use their phones for text messaging. Text messaging and phone call interventions have showed improved ART adherence but these function to automate individual level cues to action. Social media platforms permit virtual communities and can serve as a place for peer support group activities. However, it is not clear what is the best way to create online peer support groups in m-Health interventions, either through integration into established social media platforms or developing "new" social media platforms. "New" social media platforms have an advantage of broad complement functionality, but these need time to develop and phones that are more advanced not readily available in low income setting like Uganda. Besides concerns about stigma associated with mobile apps developed for HIV-positive people may make them unacceptable in communities where HIV is stigmatised . In low-income settings, peer support groups integrated into established social media platforms may be more feasible. Established social media platforms used to offer peer support among People Living with HIV/AIDS (PLWHIVA) include we chat, WhatsApp, Weibo in China and Facebook. Youth largely use Facebook to connect with their peers, but impression management is a major challenge among young Facebook users. This might be exacerbated among YLHIVA as they struggle with self-images. In a recent study conducted in south Africa, YLHIVA expressed preference for online peer support groups integrated into established social media platforms which use minimal data such as WhatsApp. Further more recent research on m-Health interventions for youth, have stressed the need for multifaceted approaches. These include; provision of credible, up-to-date information on HIV and general health and wellness, reminders that focus on ART adherence, those that ease connections to providers and other YLHIVA . WhatsApp offers the flexibility needed for the multifaceted m- health approach and permits virtual communities for peer support groups. WhatsApp documents and videos features offer an avenue for group education. WhatsApp calls and texts ease direct connections to providers, thus enhancing real-time engagement to receive individualized support. In addition, the public uses WhatsApp and so they may not refer to it as an "HIV App".

There is growing evidence that online peer support groups improve psychosocial outcomes, ART adherence and VLS among PLHIVA . However, majority of the studies have been conducted among key populations and very few have examined its benefits among YLHIVA. Among YLHIVA in the US, an online peer support group improved VLS from 64.1% to 91.4% and ART adherence (90.1% vs 57.5% at eight weeks follow-up; difference=31.1, p=.02). On the other hand, in SSA no significant improvements in ART adherence were observed among youth enrolled into online peer support groups. However, these studies had limited sample size and short follow-up periods. Given the mixed results, further evidence on the effectiveness of online peer support groups in improving HIV treatment outcomes among YLHIVA in SSA is required.

In Sub-Saharan Africa, qualitative work has underscored the psychosocial benefits of online peer support groups for YLHIVA. Youth have reported that online peer support groups reduced isolation, increased self-esteem, helped them to sustain efforts towards healthy living and work through the everyday struggles of ART adherence .Youth have described online peer support group as a safe and private community where one could be understood and valued. Furthermore, online peer support groups have improved HIV knowledge but their effect on HIV stigma among YLHIVA in SSA remains unknown. Yet stigma attached to HIV is believed to underpin many of the social, cultural, and psychological barriers to ART adherence. Furthermore, a meta-analysis by Ninke and colleagues, showed that ART adherence was strongly related to adherence self-efficacy. Therefore, the effect of online peer support groups on adherence self-efficacy needs to be understood. In addition, previous studies found that youth with HIV on online support groups felt helpless when group members posted suicidal thoughts. Such discussions are associated with increased depression, though online peer support groups have shown decreased depression among youth with mental problems. The effect of online peer support groups on depression among YLHIVA remains unknown and there is need further investigation in this area.

The utility of online peer support groups has potential to improve ART adherence among YLHIVA in Uganda. Thus, the aim of this study is to explore a WhatsApp peer support group as a strategy to improve ART adherence among youth aged 15-24 years in Kampala district. The study findings will help to advance the knowledge on virtual support as a peer support model in sub-Saharan Africa. The social cognitive theory will guide the study to capture the complex psychosocial profiles of youth ART adherence and retention in care.