Ethno-epidemiology of Hepatitis C (HCV), HIV and Overdose associated with Drug Markets and Drug Tourism

The project aimed to increase access and uptake of COVID-19 testing and vaccination among people who inject drugs (PWID), a population highly vulnerable to COVID-19. This RADx-UP project, LinkUP, was nested within the San Diego component of the parent grant, La Frontera, which was funded by National Institute on Drug Abuse (NIDA) in April, 2020. To date, 31% of La Frontera PWID have tested SARS-CoV-2 antibody+, of whom 65% had not previously been tested for COVID-19. Only 3% had been vaccinated by May, 2021, and 45% were vaccine hesitant. The specific aims were: AIM1: To prospectively evaluate the prevalence, predictors and barriers to COVID-19 testing among PWID. AIM2: To prospectively assess incidence, predictors, and barriers to COVID-19 vaccination among PWID. AIM3: To adapt and pilot an intervention offered at a mobile syringe services program (SSP) to improve uptake of COVID-19 testing and vaccination among PWID. AIM4: To compare COVID testing and vaccination rates before and after the state introduces a) COVID-19 rapid testing, and b) COVID-19 vaccination at the SSP, which represents a natural experiment. AIM5: To prospectively assess the impact of COVID-19 testing and vaccination on PWID's behaviors. To meet Aims 1 and 2, interviews were conducted with 400 PWID in La Frontera. Results were made available in Fall 2021. Based on these findings and input from the Community and Scientific Advisor Board (CASB), the study selected and adapted a brief intervention to improve COVID-19 testing and vaccination uptake among PWID at the mobile van of the community partner, OnPoint. The OnPoint peer counselors also offered on-site rapid COVID-19 antigen testing and confirmatory PCR and referrals to the closest COVID-19 vaccination center until vaccine was offered at OnPoint by the state. The study evaluated COVID-19 vaccine update independently through ongoing La Frontera study visits, that included self-reported interview data and linage of electronic health records with the San Diego County COVID-19 database, by analyzing SARS-CoV-2 antibody patterns to differentiate between natural infection and vaccine-induced immunity. Results were used to estimate effect sizes for a future efficacy trial and shared with the RADx-UP consortium, policymakers, and program planners. Since there are 185 SSPs across the country, the study informed efforts to enable SSPs to become important 'touchpoint' to reach marginalized PWID, strengthening the nation's pandemic preparedness infrastructure to reduce COVID-19 health disparities.