A cross-sectional study of factors associated with COVID-19 testing among people who inject drugs: missed opportunities for reaching those most at risk

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.

Long-acting Injectable PrEP Interest and General PrEP Awareness among People who Inject Drugs in the San Diego-Tijuana Border Metroplex

Long-acting injectable HIV pre-exposure prophylaxis (LAI-PrEP) could help overcome multilevel challenges to HIV prevention for people who inject drugs (PWID), including those in the binational San Diego-Tijuana metroplex. Yet, general PrEP awareness and interest in LAI-PrEP remain underexplored among PWID. From 2020 to 2021, 562 HIV-negative PWID in San Diego and Tijuana completed surveys assessing general PrEP awareness and interest in oral and LAI-PrEP. Modified Poisson regression examined factors associated with general PrEP awareness. Multinomial logistic regression assessed factors associated with interest in both oral and LAI-PrEP, oral PrEP only, LAI-PrEP only, or neither. General PrEP awareness was low (18%) and associated with experiencing unsheltered homelessness (adjusted prevalence ratio [APR] = 1.50, 95% confidence interval [CI]: 0.96-2.33), past 6-month fentanyl injection (APR = 1.53, 95% CI: 1.04-2.25), and transactional sex (APR = 1.71, 95% CI: 1.06-2.76). Interest in oral PrEP only was most common (44%), followed by LAI-PrEP only (25%) and neither (16%). Compared to the odds of being interested in LAI-PrEP only, the odds of being interested in oral PrEP only were lower among those who were stopped by police (AOR = 0.38, 95% CI: 0.22-0.65), reported past 6-month fentanyl injection (AOR = 0.33, 95% CI: 0.20-0.56), polydrug use (AOR = 0.48, 95% CI: 0.27-0.86), injecting multiple times daily (AOR = 0.26, 95% CI: 0.14-0.46), receptive syringe use (AOR = 0.30, 95% CI: 0.19-0.49), and higher perceived HIV risk (AOR = 0.24, 95% CI: 0.15-0.39). Interest in LAI-PrEP was more common among PWID reporting social and structural factors that could interfere with oral PrEP adherence, suggesting LAI-PrEP implementation could increase PrEP coverage among those most vulnerable to HIV.

Drug use and COVID-19 testing, vaccination, and infection among underserved, minority communities in Miami, Florida

The Coronavirus Disease 2019 (COVID-19) pandemic has disproportionately impacted people who use drugs (PWUD). This study explored relationships between drug use, COVID-19 testing, vaccination, and infection. This cross-sectional study was conducted in Miami, Florida between March 2021 and October 2022 as part of the National Institutes of Health (NIH) Rapid Acceleration of Diagnostics-Underserved Populations (RADx-UP) initiative and the Miami Adult Studies on HIV (MASH) cohort. Users of cannabis, cocaine/crack, heroin/fentanyl, methamphetamines, hallucinogens, and/or prescription drug misuse in the previous 12 months were considered PWUD. Sociodemographic data, COVID-19 testing history, and vaccination-related beliefs were self-reported. Vaccinations were confirmed with medical records and positivity was determined with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing. Statistical analyses included chi-square tests and logistic regression. Of 1,780 participants, median age was 57 years, 50.7% were male, 50.2% Non-Hispanic Black, and 66.0% reported an annual income less than $15,000. Nearly 28.0% used drugs. PWUD were less likely than non-users to self-report ever testing positive for SARS-CoV-2 (14.7% vs. 21.0%, p = 0.006). However, 2.6% of participants tested positive for SARS-CoV-2, with no significant differences between PWUD and non-users (3.7% vs. 2.2%, p = 0.076). PWUD were more likely than non-users to experience difficulties accessing testing (10.2% vs. 7.1%, p = 0.033), vaccine hesitancy (58.9% vs. 43.4%, p = 0.002) and had lower odds of receiving any dose of a COVID-19 vaccine compared to non-users (aOR, 0.63; 95% CI, 0.49-0.81; p<0.001). PWUD presented with greater difficulties accessing COVID-19 testing, greater vaccine hesitancy, and lower odds of vaccination. Testing and immunization plans that are tailored to the needs of PWUD and consider access, trust-building campaigns, and education may be needed.

High COVID-19 vaccine uptake following initial hesitancy among people in Australia who inject drugs

BACKGROUND

Previous studies have reported high COVID-19 vaccine hesitancy among people who inject drugs. We aimed to examine COVID-19 vaccine coverage, motivations and barriers to vaccination, and factors associated with uptake among this population in Australia, 1.5 years after vaccine rollout commenced.

METHODS

In June-July 2022, 868 people (66.0 % male, mean age 45.6 years) who regularly inject drugs and reside in an Australian capital city reported the number of COVID-19 vaccine doses they had received and their primary motivation (if vaccinated) or barrier (if unvaccinated) to receive the vaccine. We compared vaccine uptake to Australian population estimates and used logistic regression to identify factors associated with ≥ 2 dose and ≥ 3 dose uptake.

RESULTS

Overall, 84.1 % (n = 730) had received at least one COVID-19 vaccine dose, 79.6 % (n = 691) had received ≥ 2 doses, and 46.1 % (n = 400) had received ≥ 3 doses. Participants were less likely to be vaccinated than the Australian general population (prevalence ratio: 0.82, 95 % confidence interval [CI]: 0.76-0.88). Key motivations to receive the vaccine were to protect oneself or others from COVID-19, while barriers pertained to vaccine or government distrust. Opioid agonist treatment (adjusted odds ratio [aOR]: 2.49, 95 % CI: 1.44-4.42), current seasonal influenza vaccine uptake (aOR: 6.76, 95 % CI: 3.18-16.75), and stable housing (aOR: 1.58, 95 % CI: 1.02-2.80) were associated with receipt of at least two vaccine doses. Participants aged ≥ 40 years (versus < 40 years; aOR: 1.66, 95 % CI: 1.10-2.53) or who reported a chronic health condition (aOR: 1.71, 95 % CI: 1.18-2.47) had higher odds of receiving at least three vaccine doses.

CONCLUSION

We observed higher COVID-19 vaccine uptake than expected given previous studies of vaccine acceptability among people who inject drugs. However, it was lower than the general population. People who inject drugs and reside in unstable housing are a subpopulation that require support to increase vaccine uptake.

WaSH insecurity and anxiety among people who inject drugs in the Tijuana-San Diego border region

BACKGROUND

Water, sanitation, and hygiene (WaSH) insecurity increases the risk of water-related diseases. However, limited research has been conducted on psychosocial distress as it relates to WaSH insecurity, especially among people who inject drugs (PWID). We examined the relationship between WaSH insecurity and related anxiety among PWID living in different housing conditions along the US-Mexico border region.

METHODS

From 2020-2021, a cross-sectional study was conducted among 585 people who injected drugs within the last month in Tijuana (N = 202), San Diego (N = 182), and in both Tijuana and San Diego (N = 201). Participants underwent interviewer-administered surveys related to WaSH access, substance use, and generalized anxiety disorder (GAD-7). Quasi-Poisson regressions were used to assess associations between WaSH insecurity and anxiety in the prior 6-months.

RESULTS

Participants were 75% male, 42% were unhoused and 91% experienced WaSH insecurity in the prior 6-months. After adjusting for housing status, gender, and age, lack of access to basic drinking water (Adj RR: 1.28; 95% CI: 1.02-1.58), sanitation (Adj RR:1.28; 95% CI: 1.07-1.55), and a daily bath/shower (Adj RR: 1.38; 95% CI: 1.15-1.66) were associated with mild-severe anxiety. The number of WaSH insecurities was independently associated with a 20% increased risk of experiencing anxiety per every additional insecurity experienced (Adj RR: 1.20; CI: 1.12-1.27). We also found a significant interaction between gender and housing status (p = 0.003), indicating that among people experiencing sheltered/unsheltered homelessness, women had a higher risk of mild-severe anxiety compared to men (Adj RR: 1.55; 95% CI: 1.27-1.89). At the same time, among women, those who are unhoused have 37% increased risk of anxiety than those who live in stable housing conditions (Adj RR: 1.37; 95% CI: 1.01-1.89).

CONCLUSION

The lack of specific WaSH services, particularly lack of drinking water, toilets, and daily showers were associated with higher levels of anxiety among PWID in the Tijuana-San Diego border region. Women experiencing homelessness were especially vulnerable. WaSH interventions that provide safe, 24-h access may help to reduce anxiety and health risks associated with WaSH insecurity.

Prevalence and correlates of SARS-CoV-2 seropositivity among people who inject drugs in Baltimore, Maryland

Background

SARS-CoV-2 serosurveys can help characterize disparities in SARS-CoV-2 infection and identify gaps in population immunity. Data on SARS-CoV-2 seroprevalence among people who inject drugs (PWID) are limited.

Methods

We conducted a cross-sectional study between December 2020 and July 2022 among 561 participants in the AIDS Linked to the IntraVenous Experience (ALIVE) study-a community-based cohort of current and former PWID in Baltimore, Maryland. Serum samples were assayed for infection-induced anti-nucleocapsid (anti-N) and infection and/or vaccination-induced anti-spike-1 (anti-S) SARS-CoV-2 IgG. We estimated adjusted prevalence ratios (aPR) via modified Poisson regression models.

Results

The median age was 59 years, 35% were female, 84% were non-Hispanic Black, and 16% reported recent injection drug use. Anti-N antibody prevalence was 26% and anti-S antibody prevalence was 63%. Anti-N and anti-S antibody prevalence increased over time. Being employed (aPR=1.53 [95%CI=1.11-2.11]) was associated with higher anti-N prevalence, while a cancer history (aPR=0.40 [95%CI=0.17-0.90]) was associated with lower anti-N prevalence. HIV infection was associated with higher anti-S prevalence (aPR=1.13 [95%CI=1.02-1.27]), while younger age and experiencing homelessness (aPR=0.78 [95%CI=0.60-0.99]) were factors associated with lower anti-S prevalence. Substance use-related behaviors were not significantly associated with anti-N or anti-S prevalence.

Conclusions

SARS-CoV-2 seroprevalence increased over time among current and former PWID, suggesting cumulative increases in the incidence of SARS-CoV-2 infection and vaccination; however, there were disparities in infection-induced seroprevalence and infection and/or vaccine-induced seroprevalence within this study sample. Dedicated prevention and vaccination programs are needed to prevent disparities in infection and gaps in population immunity among PWID during emerging epidemics.

A Brief Peer-Led Intervention to Increase COVID-19 Vaccine Uptake Among People Who Inject Drugs in San Diego County: Results From a Pilot Randomized Controlled Trial

Background

We evaluated the impact of a brief peer-led intervention on COVID-19 vaccination among people who inject drugs (PWID) presenting at syringe services program (SSP) locations in San Diego County, California.

Methods

Between March and July 2022, PWID aged ≥18 years without recent voluntary COVID-19 testing who were not up to date on COVID-19 vaccinations received a single-session motivational interviewing intervention (LinkUP) or an attention-matched didactic control condition from trained peer counselors at SSP sites randomized by week. Following either 30-minute session, counselors offered referrals to local vaccination services. Multivariable log binomial regression via generalized estimating equations assessed LinkUP effects on (1) acceptance of COVID-19 vaccination referrals immediately postintervention and (2) COVID-19 vaccine uptake at 6-month follow-up.

Results

COVID-19 vaccination outcomes were obtained on 135 (90.6%) of 149 participants. In multivariable analysis, participants receiving LinkUP had greater acceptance of COVID-19 vaccination referrals than controls (adjusted relative risk, 3.50; 95% CI, 1.01-12.2) and were marginally more likely to report receiving a new COVID-19 vaccine dose (adjusted relative risk, 1.57; 95% CI, .99-2.48). After 6 months, 20% reported receiving a new vaccine dose; however, if COVID-19 vaccine had been available at SSPs, this proportion could have been as high as 34.3% (45.3% LinkUP vs 24.3% control; P = .01).

Conclusions

A brief peer-led SSP-based intervention significantly improved COVID-19 vaccination among PWID. Further improvements could likely be obtained by supporting SSPs to offer COVID-19 vaccination on-site instead of relying on referrals.

Clinical Trials Registration

ClinicalTrials.gov NCT05181657.

Preliminary Efficacy of a Theory-Informed Intervention to Increase COVID-19 Testing Uptake Among People Who Inject Drugs in San Diego County: Findings From a Pilot Randomized Controlled Trial

BACKGROUND

People who inject drugs (PWID) have low rates of COVID-19 testing yet are vulnerable to severe disease. In partnership with a mobile syringe service program (SSP) in San Diego County, CA, we developed the evidence-, community-, and Social Cognitive Theory-informed "LinkUP" intervention (tailored education, motivational interviewing, problem-solving, and planning) to increase COVID-19 testing uptake among PWID.

PURPOSE

To assess preliminary efficacy of LinkUP in increasing PWID COVID-19 testing in a pilot randomized controlled trial (RCT).

METHODS

We referred participants (PWID, ≥18 years old, San Diego County residents who had not recently undergone voluntary COVID-19 testing) to mobile SSP sites that had been randomized (by week) to offer the active LinkUP intervention or didactic attention-control conditions delivered by trained peer counselors. Following either condition, counselors offered on-site rapid COVID-19 antigen testing. Analyses estimated preliminary intervention efficacy and explored potential moderation.

RESULTS

Among 150 participants, median age was 40.5 years, 33.3% identified as Hispanic/Latinx, 64.7% were male, 73.3% were experiencing homelessness, and 44.7% had prior mandatory COVID-19 testing. The LinkUP intervention was significantly associated with higher COVID-19 testing uptake (p < .0001). Homelessness moderated intervention effects; LinkUP increased COVID-19 testing uptake more among participants experiencing homelessness (adjusted risk ratio [aRR]: 1.80; 95% CI: 1.56-2.09; p < .0001) than those not experiencing homelessness (aRR: 1.20; 95% CI: 1.01-1.43; p = .04).

CONCLUSIONS

Findings from this pilot RCT support the preliminary efficacy of the "LinkUP" intervention to increase COVID-19 testing among PWID and underscore the importance of academic-community partnerships and prevention service delivery through SSPs and other community-based organizations serving vulnerable populations.

Network-level HIV risk norms are associated with individual-level HIV risk and harm reduction behaviors among people who inject drugs: a latent profile analysis

The COVID-19 related U.S.-Mexico border-crossing restrictions disrupted social networks and HIV harm reduction services among people who inject drugs (PWID) in San Diego and Tijuana. We assessed associations of descriptive network norms on PWID's HIV vulnerability during this period. Between 10/2020 and 10/2021, 399 PWID completed a behavioral and egocentric questionnaire. We used Latent Profile Analysis to categorize PWID into network norm risk profiles based on proportions of their network (n = 924 drug use alters) who injected drugs and engaged in cross-border drug use (CBDU), among other vulnerabilities. We used logistic and linear regressions to assess network profile associations with individual-level index of HIV vulnerability and harm reduction behaviors. Fit indices specified a 4-latent profile solution of descriptive network risk norms: lower (n = 178), moderate with (n = 34) and without (n = 94) CBDU and obtainment, and higher (n = 93). Participants in higher risk profiles reported more HIV vulnerability behaviors and fewer harm reduction behaviors. PWID's gradient of HIV risk was associated with network norms, warranting intervention on high-vulnerability networks when services are limited.

Understanding Vaccine Perceptions and Willingness to Receive COVID-19 Vaccination: Opportunities to Strengthen Public Health Responses and COVID-19 Services for People Who Use Drugs

Background: People who use drugs (PWUD) are at high risk for COVID-19 infection, morbidity, and mortality. COVID-19 vaccines are safe and effective at reducing serious illness and death from COVID-19. There are sparse data on the perceptions and willingness of PWUD to receive COVID-19 vaccination. Materials and Methods: In order to assess the perceptions of, and willingness to receive, COVID-19 vaccination among PWUD, we conducted a rapid survey-based assessment of 100 PWUD in NYC (Spring 2021) who reported not having received COVID-19 vaccination and who reported past 30-day illicit drug use. Results: More than 80% of respondents agreed that personally receiving a COVID-19 vaccine was important for the health of others in the community, and endorsing this belief was significantly associated with COVID-19 vaccine willingness reflecting a high prevalence of altruistic beliefs (p-value: 0.01). Other reported perceptions that were significantly associated with COVID-19 vaccine willingness were believing that COVID-19 vaccines are safe for PWUD and trusting COVID-19 information from their healthcare providers (p-values < 0.05). That said, 62% reported being unwilling to receive a COVID-19 vaccine, and 70−83% had concerns about general vaccine safety/efficacy. Examining pairs of questions to explore potential ambivalence between vaccine endorsement and vaccine concerns identified that 56−65% simultaneously reported vaccine safety/efficacy concerns and beliefs that vaccination was an important intervention. Of the 75 respondents who reported past 30-day use of harm reduction and/or substance use disorder (SUD) programs, nearly 90% reported these programs as trusted sources of COVID-19 information. Conclusion: Most participants reported altruistic beliefs about the role of vaccines for community health, including COVID-19 vaccines, and this altruism was associated with willingness to be vaccinated against COVID-19. These findings suggest a complex relationship between beliefs about the role of vaccination in community health and the safety/efficacy of vaccines; this ambivalence suggests that COVID-19 vaccine willingness may not be firmly fixed, indicating potential opportunities to address questions and build vaccine confidence. Harm reduction and SUD programs could be leveraged to further engage PWUD in receipt of COVID-19 information and/or vaccination. Recognizing vaccine ambivalence, emphasizing collective and individual benefits of vaccination, and messaging from trusted sources may be promising approaches to increase vaccination in this population.

SARS-CoV-2 Infections in a High-Risk Migratory Population Arriving to a Migrant House along the US-Mexico Border

Few reports exist on the COVID-19 epidemiology of migrant populations. We tested 370 migratory individuals from ten countries arriving at a migrant house along the US–Mexico border based on a rapid assay detecting SARS-CoV-2 antigen. Fifty-six were positive, for a prevalence of 15.1% (95%–CIs of 11.8–19.2%). Only 21 positive persons presented signs or symptoms associated with the infection (95%–CIs = 25–49%). Most (51.7%) positive migrants arrived in the previous two days before being tested, indicating that the virus infection was acquired during their transit. Out of the total of 56 positive individuals, 37.5% were from El Salvador, 33.9% from Honduras, and 21.4% from Guatemala. This study suggests that vulnerable populations traveling from countries in Latin America and seeking residence in the US are high-risk individuals for exposure to SARS-CoV-2. The rapid antigen COVID-19 testing on arrival at the migrant house, and subsequent 10-day quarantine, was a critical step to help minimize further transmission. Therefore, the present study demonstrates that public health services provided to migratory and vulnerable populations are necessary for pandemic control.

Study protocol for a pilot randomized controlled trial to increase COVID-19 testing and vaccination among people who inject drugs in San Diego County

BACKGROUND

People who inject drugs (PWID) have low rates of COVID-19 testing and vaccination and are vulnerable to severe disease. We partnered with a local, community-based syringe service program (SSP) in San Diego County, CA, to develop the single-session theory- and evidence-informed "LinkUP" intervention to increase COVID-19 testing and vaccination. This paper details the protocol for a pilot randomized controlled trial (RCT) of the LinkUP intervention.

METHODS

With significant community input into study design considerations, including through our Community and Scientific Advisory Board, the LinkUP pilot RCT leverages an ongoing cohort study with adult (≥ 18 years) PWID in San Diego County to recruit participants who have not recently undergone voluntary COVID-19 testing and are unvaccinated. Eligible participants are referred to SSP locations randomized to offer the active intervention (involving tailored education, motivational interviewing, and problem-solving strategies) or a didactic attention-control condition (information sharing only). Both conditions are delivered by trained peer counselors hired by the SSP and were designed to be delivered at mobile (outdoor) SSP sites in ~ 30 min. Intake data assesses COVID-19 testing and vaccination history, health status, and harm reduction needs (to facilitate SSP referrals). At the end of either intervention condition, peer counselors offer onsite rapid COVID-19 antigen testing and COVID-19 vaccination referrals. Out-take and follow-up data (via SSP and state health department record linkages) confirms whether participants received the intervention, COVID-19 testing (and results) onsite or within six months, and vaccination referrals (and uptake) within six months. Planned analyses, which are not powered to assess efficacy, will provide adequate precision for effect size estimates for primary (COVID-19 testing) and secondary (vaccination) intervention outcomes. Findings will be disseminated widely including to local health authorities, collaborating agencies, and community members.

DISCUSSION

Lessons from this community-based pilot study include the importance of gathering community input into study design, cultivating research-community partnerships based on mutual respect and trust, and maintaining frequent communication regarding unexpected events (e.g., police sweeps, neighborhood opposition). Findings may support the adoption of COVID-19 testing and vaccination initiatives implemented through SSPs and other community-based organizations serving vulnerable populations of people impacted by substance use and addiction. Trial registration This trial was registered prospectively at ClinicalTrials.gov (identifier NCT05181657).