Abstract: This RADx-UP Phase II proposal, “Social network diffusion of COVID-19 prevention for diverse Criminal Legal Involved Communities”, will implement a situation appropriate COVID-19 testing and vaccination social network diffusion intervention – C3 – building upon RADx-UP Phase I lessons and successful social network prevention interventions developed previously by the research team. C3 Criminal Legal Involved (CLI) populations encompass those non-incarcerated who have experienced recent arrest, incarceration, probation, parole or diversion programs such as drug courts. While increases in COVID-19 testing have been observed among this group, there remain members with limited testing history as well as individuals who are vaccine hesitant. COVID-19 prevention messaging can no longer be simplified to “everyone test and/or everyone vaccinate” as testing and vaccination decisions among community members are sensitive to personal histories (i.e., prior infection), local infection rates (i.e., low rates) and testing/vaccination availability. As COVID-19 prevention efforts have become more complicated (i.e., test if exposed), people tend to focus on the messenger, and particularly those that are close to them. Personal connections and communications within existing personal network structures, such as families, friends and other trusted acquaintances represent the cornerstone to increase situation appropriate testing and overcoming COVID-19 vaccine hesitancy. C3 builds upon RADx-UP I, by using a network diffusion approach facilitated through motivational interviewing purposefully geared to mobilize one’s own organic social network to increase context appropriate testing and vaccine uptake. Through this process we will maximize the primary benefit and impact of this type of intervention which also has the intended effect of increasing likelihood that the messenger themselves will undergo the same behavior change that they have been trained to promote. We will leverage infrastructure developed in RADx-UP Phase I, which includes 4 high-impact sites across the Central US from Phase I: Baton Rouge LA, Little Rock AR, Indianapolis IN, and Chicago IL. We will utilize established engagement efforts already in place and continue to fully integrate communities in the strategic application of the intervention. We will use the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework to guide implementation. C3 aims to: Aim 1a. Test the efficacy (3-month situation appropriate testing or vaccination) of a network diffusion intervention (C3) versus an existing COVID-19 testing and vaccine linkage to care intervention among: 1) primary study participants (primary outcome); and 2) secondary study participants connected to primary participants (secondary outcome) using a RCT design. Aim 1b. Explore the mechanisms for differential intervention effects at the individual and network-level that may increase situation appropriate testing and/or vaccination uptake. Aim 2. Examine key RE-AIM components in real time tied to the implementation of the network diffusion intervention (C3).

Narrative: This RADx-UP Phase II proposal, “Social network diffusion of COVID-19 prevention for diverse Criminal Legal Involved (CLI) Communities”, will implement a situation appropriate COVID-19 testing and vaccination social network diffusion intervention. COVID-19 prevention messaging can no longer be simplified to “everyone test and/or everyone vaccinate” as testing and vaccination decisions among community members are sensitive to personal histories (i.e., prior infection), local infection rates (i.e., low rates) and testing/vaccination availability. We build upon RADx-UP Phase I, by using a network diffusion approach facilitated through motivational interviewing purposefully geared to mobilize one’s own organic social network to increase situation appropriate testing and vaccine uptake.