Identifying Missed Opportunities for Routine Vaccination among People Who Use Drugs

Vaccination coverage among people who inject drugs: A systematic review

BACKGROUND

People who inject drugs may be at excess risk of acquiring vaccine-preventable diseases and negative associated health outcomes, but experience barriers to vaccination. We aimed to determine vaccination coverage among people who inject drugs globally.

METHODOLOGY

We conducted systematic searches of the peer-reviewed and grey literature, date limited from January 2008 to August 2023, focusing on diseases for which people who inject drugs are at elevated risk for and for which an adult vaccination dose is recommended (COVID-19, hepatitis A, hepatitis B, human papillomavirus, influenza, pneumococcal disease, tetanus). To summarise available data, we conducted a narrative synthesis.

RESULTS

We included 78 studies/reports comprising 117 estimates of vaccination coverage across 36 countries. Most estimates were obtained from high income countries (80%, n=94). We located estimates for hepatitis B vaccination in 33 countries, which included 18 countries with data on serological evidence of vaccine-derived hepatitis B immunity (range: 6-53%) and 22 countries with self-report data for vaccine uptake (<1-96%). Data for other vaccines were scarcer: reported hepatitis A vaccination coverage ranged 3-89% (five countries), COVID-19 ranged 4-84% (five countries), while we located estimates from fewer than five countries for influenza, tetanus, pneumococcal disease, and human papillomavirus.

CONCLUSION

Estimates were sparse but where available indicative of suboptimal vaccination coverage among people who inject drugs. Improving the consistency, timeliness, and geographic coverage of vaccine uptake data among this population is essential to inform efforts to increase uptake.

Opiate maintenance patients' attitudes and self-reported adherence to protective measures against SARS-CoV-2 infections

Background

During the COVID-19 pandemic we assessed to which extent patients in opioid maintenance treatment (OMT) adhere to official recommendations regarding preventive intervention strategies against COVID-19.

Methods

Patients enrolled in two OMT clinics in Germany were interviewed applying a standardized questionnaire, which covered socio-demographic information, recent psychotropic substance use, recent social activities, the history of SARS-CoV-2 infection, attitudes toward official protection recommendations, and levels of adherence to these suggestions. Current mental and medical diagnoses were retrieved from medical files. In subjects without known infection and without vaccination, blood samples were tested for the identification of anti-SARS-CoV-2-S-antibodies. Interviews were performed between the end of May and the end of September 2021.

Results

Patients' (n = 155) average age was 47 years; 74% were males. In addition to the opiate dependence, in nearly 80% of cases another medical disorder was recorded. The range of medical factors that predispose for severe COVID-19 outcomes were present in 39% of patients; 18% of the sample refused to be vaccinated. Nearly all patients reported having carried out a range of activities outside their residence during the week prior to the interviews, including visits of treatment facilities (86.5%; 95% confidence interval [80.2%; 91.0%]) or meeting with friends (64.5% [65.7-71.6%]). Despite the fact that only about 47.1% [39.2%; 55%] felt well informed about measures against infection, adherence to COVID-19 countermeasures was generally high: 83.9% [77.3; 88.8%] claimed to have worn face masks always/nearly always; social distancing was performed always/nearly always by 58.7% [50.8%; 66.2%]; and hand hygiene was conducted by 64.5% [56.7%; 71.6%] of participants. None out of n = 25 tests from unvaccinated subjects was positive for anti-SARS-CoV-2-S-antibodies. Psychiatric comorbidity and educational degree were not statistically significantly associated with attitudes and compliance, except that patients with lower education felt relatively worse informed.

Conclusion

Self-reported adherence to recommended non-therapeutic intervention strategies and vaccination rates were similar to the German general population. Provision of more health-related information tailored to OMT patients appears necessary.

Identifying barriers and facilitators to COVID-19 vaccination uptake among People Who Use Drugs in Canada: a National Qualitative Study

BACKGROUND

People Who Use Drugs (PWUD) have lower vaccination uptake than the general population, and disproportionately experience the burden of harms from vaccine-preventable diseases. We conducted a national qualitative study to: (1) identify the barriers and facilitators to receiving COVID-19 vaccinations among PWUD; and (2) identify interventions to support PWUD in their decision-making.

METHODS

Between March and October 2022, semi-structured interviews with PWUD across Canada were conducted. Fully vaccinated (2 or more doses) and partially or unvaccinated (1 dose or less) participants were recruited from a convenience sample to participate in telephone interviews to discuss facilitators, barriers, and concerns about receiving COVID-19 vaccines and subsequent boosters, and ways to address concerns. A total of 78 PWUD participated in the study, with 50 participants being fully vaccinated and 28 participants partially or unvaccinated. Using thematic analysis, interviews were coded based on the capability, opportunity, and motivation-behavior (COM-B) framework.

RESULTS

Many partially or unvaccinated participants reported lacking knowledge about the COVID-19 vaccine, particularly in terms of its usefulness and benefits. Some participants reported lacking knowledge around potential long-term side effects of the vaccine, and the differences of the various vaccine brands. Distrust toward government and healthcare agencies, the unprecedented rapidity of vaccine development and skepticism of vaccine effectiveness were also noted as barriers. Facilitators for vaccination included a desire to protect oneself or others and compliance with government mandates which required individuals to get vaccinated in order to access services, attend work or travel. To improve vaccination uptake, the most trusted and appropriate avenues for vaccination information sharing were identified by participants to be people with lived and living experience with drug use (PWLLE), harm reduction workers, or healthcare providers working within settings commonly visited by PWUD.

CONCLUSION

PWLLE should be supported to design tailored information to reduce barriers and address mistrust. Resources addressing knowledge gaps should be disseminated in areas and through organizations where PWUD frequently access, such as harm reduction services and social media platforms.

Vaccine confidence among people who use drugs: A cross-sectional survey

Adult immunization coverage remains low in the US, particularly for people who use drugs (PWUD), a population that experiences a disproportionate burden of vaccine-preventable diseases. The extent of and characteristics associated with vaccine confidence (VC) held by PWUD is poorly understood. As VC strongly correlates with vaccine uptake, this cross-sectional study identifies mutable factors associated with VC and quantifies its relationship to immunization status within a highly vulnerable, underimmunized population of PWUD. Using a community-engaged research strategy with select partner organizations hosting syringe exchange programs in Atlanta, Los Angeles, and Las Vegas, USA, we surveyed participants ages 18-69 years served by these organizations from 2019 to 2020. Survey measures included sociodemographics, health behavior including immunization receipt, and vaccine confidence in adult vaccinations using a modified Emory Vaccine Confidence Index (EVCI). The findings reflect relatively low VC among the 1,127 recruited participants, with 56% expressing low VC (EVCI 0-12), 35% medium (EVCI 13-20) and 10% high (EVCI 21-24). EVCI varied by city, with lowest confidence in Atlanta and highest in Las Vegas. VC was associated with past receipt of specific vaccines, including hepatitis A, MMR, Tdap, and influenza. VC varied by specific sociodemographic correlates such as housing insecurity (reduced confidence) and receipt of public benefits or disability (increased confidence). This study identified correlates associated with VC based on site and sociodemographic characteristics for this priority population, highlighting the need for specific interventions to raise VC among PWUD, especially among those experiencing housing insecurity and without public benefits.

Vaccination barriers and opportunities at syringe services programs in the United States, June-August 2021-A cross-sectional survey

BACKGROUND

Syringe services programs (SSPs) are an important venue for reaching people who inject drugs (PWID) to offer preventive services; however, not all SSPs offer vaccinations. We aimed to describe barriers and opportunities for SSPs to offer vaccinations.

METHODS

During June-August 2021, we conducted a descriptive, cross-sectional survey of SSP providers in the United States. SSPs were recruited from national listservs using purposive sampling to ensure geographic diversity. The survey included questions about SSP characteristics, client demographics, existing vaccination resources, resource needs, and staff perspectives on client vaccination barriers. Statistical comparisons were made using Pearson's chi-square test.

RESULTS

In total, 105 SSPs from 34 states responded to the survey; 46 SSPs (43.8%) offered on-site vaccinations. SSPs without on-site vaccinations were more likely operated by community-based organizations (81.4% vs 30.4%, p < 0.001) in urban areas (71.4% vs 40.0%, p = 0.002) than SSPs offering on-site vaccinations. The most common staffing need was for personnel licensed to administer vaccines (74/98, 75.5%). Over half of SSPs reported vaccine supply, administration supplies, storage equipment, and systems to follow-up clients for multidose series as important resource needs. The most common resource need was for reminder/recall systems for vaccines with multidose series (75/92, 81.5%). Vaccine safety concerns (92/95, 96.8%) and competing priorities (92/96, 95.8%) were the most common staff-reported client barriers to vaccinations.

CONCLUSIONS

Addressing missed opportunities for offering vaccinations to PWID who use SSPs will require increased numbers of on-site personnel licensed to administer vaccines and additional training, vaccination supplies, and storage and handling equipment.

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

Introduction

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.

Methods

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.

Results

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%).

Discussion and Conclusions

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.