Background. Opioid Agonist Treatment (OAT) is known to be effective in both treating Opioid Use Disorders (OUD) and reducing adverse outcomes. The LASSO program in Oslo, Norway, is a low-threshold OAT clinic which initially only offered patients buprenorphine/naloxone (BPNX) until 2017 when buprenorphine (BP) was introduced as an alternative. Aims: To investigate the impact of increased medication options on treatment adherence and enrollment in a low-threshold OAT program. Methods: All patient contacts from January 1st, 2011 until December 31st, 2019 and all medical charts from January 1st 2017 until December 31st 2019 were included. Differences in recruitment and retention were compared between three time periods; 1) when the clinic was established 2011-14, 2) when there was a dip in recruitment 2015-16 and 3) after BP was introduced in 2017-19. A linear regression model was used to predict total treatment time and Kaplan-Meier survival curves were used to identify the most vulnerable period for attrition. Results: Recruitment: There was a 37.8% increase in total number of patients between periods 2-3 and a 12.9% increase between periods 1-3. Treatment time: Both number of induction attempts and attrition within the first 30 days was predictive of total treatment time. Each induction provided 15 additional days in treatment. Remaining in treatment for 30 days was predictive of completing an additional 70 days of treatment. Patients who changed medications at least once remained in treatment 79 days (BPNX to BP) and 158 days (BP to BPNX). Those who remained on one medication (BPNX or BP) remained in treatment for 35 days. Attrition: 25.7% of patients fell out of treatment prior to day 3 while 50% of patients fell out of treatment prior to day 12 during their first treatment episode. Conclusions: Offering patients a choice between BP and BPNX increased both recruitment and treatment retention. The "option to choose" rather than medication choice seems to be of prognostic value. Furthermore, given the high attrition rate within the first two days, it seems appropriate to re-evaluate titration procedures and intensify psychosocial support efforts during this challenging time.

BACKGROUND:During the initial wave of the COVID-19 pandemic, there was a surprisingly low incidence of SARS-CoV-2 among People Who Use Drugs (PWUD) in Oslo, Norway, despite their heightened vulnerability regarding risk of infection and severe courses of the disease.This study aims to investigate the seroprevalence of SARS-CoV-2 antibodies among PWUD, their antibody responses to relevant virus infections and COVID-19 mRNA vaccines, and their vaccination coverage compared to the general population. METHODS:Conducted as a prospective cohort study, data was collected from residents in six institutions for homeless PWUD and users of a low-threshold clinic for opioid agonist treatment. Ninety-seven participants were recruited for SARS-CoV-2 seroprevalence analysis. Additional two participants with known positive SARS-CoV-2 test results were recruited for further analyses. Twenty-five participants completed follow-up. Data included questionnaires, nasal swabs and blood samples. Data on vaccination coverage was obtained from the National Vaccine Register. Serologic methods included detection of antibodies to relevant virus proteins, neutralizing antibodies to SARS-CoV-2, antibodies to the full-length spike protein, and receptor-binding domain from SARS-CoV-2. RESULTS:Among PWUD, antibodies to SARS-CoV-2 were detected in 2 out of 97 samples before vaccines against SARS-CoV-2 were available, comparable to a 2.8% frequency in population-based screening. Levels of serum antibodies to seasonal coronaviruses and Epstein-Barr-Virus (EBV) in PWUD were similar to population-based levels. After the second vaccine dose, binding and neutralizing antibody levels to SARS-CoV-2 in PWUD were comparable to controls. Eighty-four of PWUD received at least one dose of COVID-19 mRNA vaccine, compared to 89% in the general population. CONCLUSION:Results indicate that PWUD did not exhibit increased SARS-CoV-2 seroprevalence or elevated serum antibodies to seasonal coronaviruses and EBV. Moreover, vaccine responses in PWUD were comparable to controls, suggesting that vaccination is effective in conferring protection against SARS-CoV-2 also in this population.

People who use drugs (PWUD) are at a high risk of contracting and developing severe coronavirus disease 2019 (COVID-19) and other infectious diseases due to their lifestyle, comorbidities, and the detrimental effects of opioids on cellular immunity. However, there is limited research on vaccine responses in PWUD, particularly regarding the role that T cells play in the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we show that before vaccination, PWUD did not exhibit an increased frequency of preexisting cross-reactive T cells to SARS-CoV-2 and that, despite the inhibitory effects that opioids have on T-cell immunity, standard vaccination can elicit robust polyfunctional CD4+ and CD8+ T-cell responses that were similar to those found in controls. Our findings indicate that vaccination stimulates an effective immune response in PWUD and highlight targeted vaccination as an essential public health instrument for the control of COVID-19 and other infectious diseases in this group of high-risk patients.

Abstract Background People who use drugs (PWUD) have increased risk of acquiring SARS-CoV-2 and having severe courses of COVID-19. However, during the first wave of the pandemic, surprisingly few PWUD tested positive for SARS-CoV-2 in Oslo. Aims: To investigate the seroprevalence of SARS-CoV-2, the antibody responses to virus infections and SARS-CoV-2 vaccines, and the vaccination rate among PWUD compared to the general population. Methods: Design: A prospective cohort study. Setting: Data was collected from residents at six institutions for homeless PWUD and users of a low-threshold clinic for opioid agonist treatment. Data was collected at baseline (N=99) and follow-up (N=25) and consisted of questionnaires and blood samples. Data on vaccination was collected from the National Vaccine Register. Serologic methods included detection of antibodies to different virus proteins, detection of neutralizing antibodies to SARS-CoV-2, and antibodies to Spike-FL, receptor-binding domain of the Spike protein and nucleocapsid from SARS-CoV-2. Results Antibodies to SARS-CoV-2 were detected in 4/99 samples from PWUD in the months before vaccines were available. The corresponding frequency for population-based screening was 2.8%. The levels of serum antibodies to seasonal coronaviruses and EBV in PWUD, were also similar to those measured in population-based screening. The levels of binding and neutralizing antibodies to SARS-CoV-2 measured in samples obtained from PWUD (N=25) after the second vaccine dose were comparable to those observed in healthy controls. Concerning humoral immune responses to COVID-19 vaccination, there was no difference between PWUD and healthy individuals. Eighty-four and eighty-nine per cent had received at least one dose of corona vaccine among PWUD and the general population, respectively. Conclusion Results showed that PWUD did not have increased seroprevalence of SARS-CoV-2 and did not have increased serum antibodies to seasonal coronaviruses and EBV. Vaccine responses were not different from controls demonstrating that vaccination is a viable strategy to confer protection against SARS-CoV-2 in PWUD

Abstract Background People who use drugs (PWUD) have increased risk of acquiring SARS-CoV-2 and having severe courses of COVID-19. However, during the first wave of the pandemic, surprisingly few PWUD tested positive for SARS-CoV-2 in Oslo. Aims: To investigate the seroprevalence of SARS-CoV-2, the antibody responses to virus infections and SARS-CoV-2 vaccines, and the vaccination rate among PWUD compared to the general population. Methods: Design: A prospective cohort study. Setting: Data was collected from residents at six institutions for homeless PWUD and users of a low-threshold clinic for opioid agonist treatment. Data was collected at baseline (N=99) and follow-up (N=25) and consisted of questionnaires and blood samples. Data on vaccination was collected from the National Vaccine Register. Serologic methods included detection of antibodies to different virus proteins, detection of neutralizing antibodies to SARS-CoV-2, and antibodies to Spike-FL, receptor-binding domain of the Spike protein and nucleocapsid from SARS-CoV-2. Results Antibodies to SARS-CoV-2 were detected in 4/99 samples from PWUD in the months before vaccines were available. The corresponding frequency for population-based screening was 2.8%. The levels of serum antibodies to seasonal coronaviruses and EBV in PWUD, were also similar to those measured in population-based screening. The levels of binding and neutralizing antibodies to SARS-CoV-2 measured in samples obtained from PWUD (N=25) after the second vaccine dose were comparable to those observed in healthy controls. Concerning humoral immune responses to COVID-19 vaccination, there was no difference between PWUD and healthy individuals. Eighty-four and eighty-nine per cent had received at least one dose of corona vaccine among PWUD and the general population, respectively. Conclusion Results showed that PWUD did not have increased seroprevalence of SARS-CoV-2 and did not have increased serum antibodies to seasonal coronaviruses and EBV. Vaccine responses were not different from controls demonstrating that vaccination is a viable strategy to confer protection against SARS-CoV-2 in PWUD

Background: This is a 6-year retrospective quality control study of the LASSO Program (Low Threshold Substitution Treatment in Oslo), using exclusively Suboxone® (buprenorphine-naloxone [BPNX]) in out-patient settings. Adequate abstinence prior to induction is necessary to avoid acute onset opioid withdrawal symptoms; thus, its use in low threshold settings is far less common than methadone. Objectives: The aim of this study was to determine if BPNX is a safe and feasible medication to use in a low threshold setting. Methods: The analysis is based on daily supervised BPNX medication. The standardized induction regime started with 4-mg BPNX increasing by 4 mg daily until 16 mg, with individual adjustments based on clinical status. Treatment effect was evaluated by the number of medication induction attempts, treatment length and lag time between initial contact and medication start. Statistical computations were performed with SPSS®. Results: There were 331 out of 394 registered patient inquires that started on BPNX. Two hundred fifty-three patients (76.4%) completed induction on first attempt with 95% Wilson score CIs of (0.716–0.807). The accumulated percentage increased to 85.2% during successive inductions. No significant association was found between lag time and (i) the number of days on medication during the first induction; or (ii) total treatment length. Patients had a median lag time of 5 days, remained in treatment a median of 52.0 days with an average of 3.9 inductions. There were no cases of severe precipitated withdrawal and only 2 cases of adverse reactions among the 1,293 inductions and 25,544 administered dosages. Conclusion: This study shows that BPNX is highly effective in treating marginalized heroin addicts in low threshold settings. Even during their first attempt, 76.4% completed induction. There were no cases of severe precipitated withdrawal. Prolonged lag time affected neither the length of first treatment nor the total treatment length. Individualized induction readiness approach and motivation were central to the above results.

Introduction: In 2014, Oslo University Hospital introduced a Safe Low Dose Methadone (SLDM) project in an effort to reach 'hard-to-treat' opioid-dependent patients that were unable to comply with previous treatment plans. The basic assumption was that a dosage of 60 mg methadone adminstered daily should provide adequate physical abstinence relief with only a low risk of respiratory depression, even when combined with central depressants. Methods: This prospective study is a follow-up of 20 'hard-to-treat' patients in SLDM over a period of 15 months. All patients were benefiting from a 'stable living situation' prior to titration. Treatment status was evaluated at 2, 7 and 15 months after the cut-off period for inclusion. Results: Eighty per cent of the patients were on methadone at the 15 months evaluation follow-up. There were no serious intoxications or overdoses reported among any of the 20 patients during the study period. Conclusions: 'Hard-to-treat' patients may be treated successfully and responsibly with low dose methadone when this takes place within a tightly controlled framework.