COVID-19 vaccination coverage and vaccine hesitancy among people with opioid use disorder in Barcelona, Spain

People with substance use disorders are considered a priority group for SARS-CoV-2 vaccination as they are at elevated risk of COVID-19 and its severe complications. However, data are scarce about vaccination coverage in a real-world setting.

A descriptive study was conducted in people with opioid use disorder (OUD) from three public centres for outpatient drug addiction treatment in Barcelona, Spain, who received brief medical advice and were referred to vaccination clinic sites.

Three hundred and sixty-two individuals were included: 277 (77%) were men with a mean age of 48.1 ± 8.9 years and 77% were Spanish. Most (90%) participants engaged in polysubstance use and all individuals were on opioid agonist therapy. Psychiatric comorbidity was present in 56% subjects and 32% individuals had ≥1 chronic disease, 30% had HIV and 13% hepatitis C. There were 258 fully vaccinated individuals (71%; 95% confidence interval [CI] 67, 76). Age (odds ratio [OR] 1.04; 95% CI 1.01, 1.08; P < 0.01) and Charlson Comorbidity Index (OR 1.67; 95% CI 1.11, 2.5; P < 0.01) were associated with full vaccination. The vaccination hesitancy causes cited were complacency (53, 51%), convenience (40, 39%) and confidence (11, 10%).

More than two-thirds of our sample of people with OUD were fully vaccinated. Complacency and convenience represented a significant barrier to complete vaccination among people with OUD on opioid agonist therapy referred to vaccination clinic sites. Additional measures are necessary to increase vaccination, especially for younger individuals and those with less medical comorbidity. Integrating vaccination services in drug outpatient centres could be a useful alternative.