COVID-19 vaccination and drug users: Past, present, and future.

Vaccination against COVID-19 is crucial in the attempt of containing the virus' spread, but facing a viral pathogen with such a high prevalence means that vaccination strategies are facing an unprecedented situation. People that use illicit drugs may have elevated risk of adverse outcomes from COVID-19 given their high prevalence of underlying medical conditions, including respiratory and pulmonary disease, chronic liver disease, cardiovascular and cerebrovascular conditions, diabetes, and compromised immune systems. Despite a widespread distribution on the Italian territory, a large presence of health personnel and a long-standing experience in vaccinations, addiction clinics have yet to be involved in the vaccination campaign against COVID-19. The aim of this study was to investigate the beliefs of drug users attending some Italian addiction clinics, in order to envisage any vaccine administration strategies involving the services themselves. A questionnaire used for the Italian general population to investigate the relative importance of some factors in influencing the propensity to vaccinate against COVID-19, was administrated to drug users in a multicenter survey. The majority of respondents expressed general confidence in vaccines and a good willingness to undergo vaccination. Given strong peer networks, high coverage of treatment and harm reduction interventions, Italian public addiction clinics could play a strategic role in administering the vaccine in this hard-to-reach population, usefully aiding the global campaign against the virus.