Comparison of hepatitis B and SARS-CoV2 vaccination rates in people who attended Drugs and Addiction Centres

Background and aimsPersons with substance use disorder are at increased risk for hepatitis B virus (HBV) infection. Although most of them are attached to social health centers, the vaccination rate in this group is low. In this context, we designed a study to evaluate the prevalence of users of drug addiction centers (DAC) not immunized against hepatitis B and to compare the rate of vaccination against hepatitis B with the rate of immunization against SARS-Cov-2 in 2 years of follow-up.DesignRetrospective study that included individuals attended at DAC. Patients were screened at baseline (June 2020–January 2021) for HBV immunization. Individuals with HBsAb < 10 IU/mL were recommended to receive hepatitis B vaccine, during follow-up (January 2021–October 2022). At the end of follow-up, the HBV vaccination rate among candidates was determined and compared with the vaccination rate against SARS-Cov-2 in this population in the same period.FindingsA total of 325 subjects were surveyed and tested. At baseline, the 65% (211/325) of were candidates to initiate vaccination and were advisor to HBV vaccination. During the follow-up 15 individuals received at least one dose of HBV vaccine, supposing a vaccination rate of 7.2%. In the same period, 186 individuals received at least one dose against SARS-Cov-2, representing a vaccination rate of 83%. The comparison between vaccination rates reached statistically significant (p