A reference in the discussion section was missing in the original article: at the end of the sentence "A recent published study assessed during the first pandemic
wave the SARS-CoV-2 seroprevalence, COVID-19
symptoms, and comorbidity among OAT patients from one
addiction outpatient unit in Dublin, Ireland" the article "Fenton F, Stokes S, Eagleton M. A cross-section observational study on the seroprevalence of antibodies to COVID-19 in patients receiving opiate agonist treatment. Ir J Med Sci. 2021. DOI 10.1007/s11845-021-02660-w" should have been cited. The original article has been corrected and the reference  added.
This correction has been made to the online version as of February 1, 2022.
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