Table 2.

LinkUP intervention targets, strategies, and specific activities

Intervention targets	Intervention strategies	Examples of specific activities	Format
Limited COVID-19 knowledge	Basic COVID-19 education	• General background on COVID-19 including symptoms • Facts on COVID-19 testing • Facts on COVID-19 vaccination (primary series and booster shots) • COVID-19 treatment information • Provision of local resources for testing and vaccination	Brief educational videos on COVID-19, testing, and vaccination (and CPR for attention-control didactic condition); appendix of local resources
Limited COVID-19 testing and vaccine motivation	Motivational interviewing	• Assessing readiness for COVID-19 testing and vaccination • Decisional balance scales (i.e., rating personal motivation) for COVID-19 testing and vaccine • Assessing individuals’ specific COVID-19 concerns • Debating and clarifying COVID-19 (mis)information (e.g., vaccine myths vs. facts) • Reviewing local COVID-19 situation and adding personal meaning	Personalized discussion informed by the principles of motivational interviewing (with reflection, affirmation, normalization)
Limited COVID-19 testing and vaccine self-efficacy and behavioral skills	Problem-solving and planning	• Identifying personally-relevant challenges to COVID-19 testing and vaccination (e.g., competing priorities, scheduling appointments when required, homelessness, transportation, etc.) • Planning for future COVID-19 testing and vaccination (listing anticipated plans, challenges to plans, and solutions)	Personalized discussion with problem-solving and planning around specific structural and social barriers
COVID-19 testing and vaccine update	(d) Offer services and referrals	• Offer on-site rapid COVID-19 antigen testing or PCR sample collection • Offer referrals for COVID-19 vaccination at nearby clinics and pharmacies	Personalized discussion