BACKGROUND: Across Sub-Saharan Africa, adolescents and young people (AYP) aged 15-24 have limited access to sexual and reproductive health (SRH) services, including HIV testing services (HTS). In response, the Yathu Yathu study was implemented in two high-density communities in Lusaka, Zambia. Yathu Yathu provides comprehensive, community-based, peer-led SRH services, including differentiated HTS (finger-prick and HIV self-testing) and comprehensive sexuality education (CSE). We describe adaptations to the Yathu Yathu intervention in response to the COVID-19 epidemic, and implications on uptake of HTS among AYP. METHODS: Yathu Yathu provides SRH services through community-based peer-led spaces. AYP in study communities were offered prevention points cards (PPC), which incentivizes and tracks service use. Social media (WhatsApp©/Facebook©) is used to engage and inform AYP about SRH. Due to COVID-19, hubs closed from April-June 2020. We describe adaptations in response to COVID-19 and, using routinely collected PPC data, describe uptake of HTS before (September 2019-March 2020) and after (July-December 2020) adaptations in response to COVID-19. We describe reach of the Yathu Yathu Facebook page and use qualitative data to describe AYP experiences of SRH service access. RESULTS: During hub closures, CSE was delivered via video on social media, resulting in an increase in Facebook page followers from 539(April) to 891(June). WhatsApp groups evolved as a platform to deliver CSE and COVID-19 information, with higher participation among young people aged 20-24. Key service delivery adaptations included: reducing the number of participants in hubs, mandatory handwashing before entry, use of personal protective equipment by staff and provision of facemasks to AYP. HTS were provided as normal. Adaptations led to fewer AYP attending hubs. Uptake of HTS among AYP visiting hubs for the first time after COVID-19-related closures was higher (73.2%) compared to uptake before adaptations (65.9%; adjOR=1.24 95%CI 0.99, 1.56, p=0.06). Despite disappointments with some aspects of service delivery, AYP expressed happiness that hubs had reopened. CONCLUSIONS: Social media can be a useful additional platform to reach AYP with HIV prevention information during COVID-19. With proper infection control in place, HTS can safely be provided to, accessed and accepted by AYP in community-based settings during COVID-19. TRIAL REGISTRATION: National Clinical Trials NCT04060420,19 August 2019. Current Controlled Trials ISRCTN75609016 , 14 September 2021, retrospectively registered.