Susceptibility to Hepatitis A and B Virus Among Clients at a Syringe Services Program in Philadelphia, 2018

The Key Importance of Screening Underprivileged People in Order to Achieve Global Hepatitis Virus Elimination Targets

Chronic hepatitis B (HBV), alongside hepatitis D virus (HDV) super-/co-infection and chronic hepatitis C (HCV), are major contributors to cirrhosis, end-stage liver disease, hepatocellular carcinoma (HCC), and liver-related mortality. Despite significant progress in antiviral treatments and HBV vaccination, viral hepatitis remains a global health burden. Vulnerable populations, such as those experiencing homelessness, migrants, and economically disadvantaged groups, are disproportionately impacted by these infections, often facing barriers to care and exclusion from traditional health systems. This leads to undiagnosed cases and ongoing transmission, undermining global efforts to eliminate HBV and HCV by 2030, as outlined by the World Health Organization (WHO). Recent studies highlight the importance of tailored interventions to address health inequalities. For instance, on-site community-based screening initiatives targeting marginalized groups have shown promise, achieving higher linkage to care rates without monetary incentives. These approaches not only enhance diagnosis but also facilitate integration into healthcare systems, addressing both public health and social disparities. This review underscores the need for targeted strategies to promote the early detection and management of HBV and HCV in underserved populations. Such efforts are critical to advancing the WHO's elimination goals, improving health outcomes, and addressing the broader social determinants of health.

Identifying barriers to hepatitis B and delta screening, prevention, and linkage to care among people who use drugs in Philadelphia, Pennsylvania, USA

BACKGROUND

People who use drugs (PWUD) are at increased risk for blood-borne viruses, including hepatitis B (HBV) and delta (HDV). Despite the public health threats both viruses present, awareness remains low among at-risk communities and providers who serve them. This study assessed barriers to HBV and HDV prevention, diagnosis, and linkage to care, evaluated existing levels of knowledge, and identified educational needs and preferences among both PWUD and service providers.

METHODS

For this mixed-methods study, data were collected through an anonymous online provider-focused survey, and interviews with PWUD, non-medical staff, and healthcare providers at a harm reduction organization in Philadelphia, PA, USA. Convenience sampling was used for recruitment of both key informants and survey respondents. Survey respondents were categorized according to their type of practice. For the interviews, a codebook was created for qualitative analysis. Data were subsequently organized into thematic categories.

RESULTS

The top provider-related barriers limiting HBV screening were identified as confusion about insurance coverage (48%) and competing priorities (45%). Barriers to vaccination included patient hesitancy (52%) and challenges with administering multiple doses (39%). Respondents indicated low knowledge of HDV tests (62%) and cited guideline complexity (31%) as barriers to HDV testing. HBV and HDV awareness within the community and among staff was poor. Findings demonstrated that stigma related to drug use and harm reduction posed a significant barrier to care. Participants recommended awareness campaigns tailored for the PWUD community that are non-stigmatizing and non-judgmental, clear, factual, digestible, and interactive, with empowering steps to protect health.

CONCLUSION

This study identified major gaps in HBV and HDV service delivery for PWUD, including poor basic knowledge, the need to address this through culturally appropriate, non-stigmatizing and tailored educational programming, and challenges with access to vaccination and testing. Continued initiatives are needed to close disparities, and to continue to provide financial and political support for harm reduction organizations, a frequently cited facilitator of healthcare access for PWUD. Significant efforts are essential to address lack of vaccination, testing, and linkage to care, and to improve health outcomes among PWUD.

Colocation of COVID-19 Vaccination Services at Syringe Service Programs for People Who Inject Drugs and People Experiencing Houselessness in Oregon

OBJECTIVES

Integrating vaccination services with other essential health services could increase vaccination rates among socially marginalized populations. We examined the associations between colocation of vaccines at syringe service programs and COVID-19 vaccination status among people who inject drugs and people experiencing houselessness.

METHODS

This study included 1891 participants aged ≥18 years at 9 sites in Oregon from July 2021 through March 2022. Participants self-reported whether they had ever received ≥1 dose of a COVID-19 vaccine. We calculated site-level COVID-19 vaccine availability and overall vaccination rates. We compared site-level vaccination rates and analyzed the association between vaccine availability and vaccination status.

RESULTS

We found no significant difference in vaccination rates between sites that did and did not offer COVID-19 vaccines (t7 = -0.33; P = .75). We also found no significant association between vaccine availability and vaccination status. However, the odds of having received a COVID-19 vaccine were 2.79 times higher for each additional site visit during which COVID-19 vaccines were available (odds ratio [OR] = 2.79; 95% CI, 2.18-3.58; P < .001). The association between vaccine availability and vaccine status was not moderated by participant age (OR = 1.03; 95% CI, 0.99-1.07; P = .13) or housing instability (OR = 0.59; 95% CI, 0.13-2.60; P = .48).

CONCLUSIONS

Colocating COVID-19 vaccines at syringe service programs was only positively associated with vaccination status if vaccines were offered frequently on-site. Future work should examine whether the frequency of offering vaccination services increases willingness to engage in vaccination and examine trust and convenience as potential mechanisms.

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.

Dismantling Barriers to Hepatitis B and Delta Screening, Prevention, and Linkage to Care among the PWUD Community in Philadelphia

The prevalence of hepatitis B and delta viruses (HBV/HDV) among people who use drugs (PWUD) remains largely unknown. In the context of one Philadelphia-based harm reduction organization (HRO), this study aimed to assess HBV/HDV prevalence and facilitate linkage to care. Participants completed a demographic HBV/HDV risk factor survey and were screened for HBV and reflexively for HDV if positive for HBV surface antigen or isolated core antibody. Fisher's exact tests and regression were used to understand relationships between risks and HBV blood markers. Of the 498 participants, 126 (25.3%) did not have hepatitis B immunity, 52.6% had been vaccinated against HBV, and 17.9% had recovered from a past infection. Eleven (2.2%) participants tested positive for isolated HBV core antibody, 10 (2.0%) for HBV surface antigen, and one (0.2%) for HDV antibody. History of incarceration was associated with current HBV infection, while transactional sex and experience of homelessness were predictive of previous exposure. This study found high rates of current and past HBV infection, and a 10% HBV/HDV co-infection rate. Despite availability of vaccine, one quarter of participants remained vulnerable to infection. Findings demonstrate the need to improve low-threshold HBV/HDV screening, vaccination, and linkage to care among PWUD. The study also identified gaps in the HBV/HDV care cascade, including lack of point-of-care diagnostics and lack of support for HROs to provide HBV services.

Determining Herd Immunity Thresholds for Hepatitis A Virus Transmission to Inform Vaccination Strategies Among People Who Inject Drugs in 16 US States

BACKGROUND

Widespread outbreaks of person-to-person transmitted hepatitis A virus (HAV), particularly among people who inject drugs (PWID), continue across the United States and globally. However, the herd immunity threshold and vaccination coverage required to prevent outbreaks are unknown. We used surveillance data and dynamic modeling to estimate herd immunity thresholds among PWID in 16 US states.

METHODS

We used a previously published dynamic model of HAV transmission calibrated to surveillance data from outbreaks involving PWID in 16 states. Using state-level calibrated models, we estimated the basic reproduction number (R0) and herd immunity threshold for PWID in each state. We performed a meta-analysis of herd immunity thresholds to determine the critical vaccination coverage required to prevent most HAV outbreaks among PWID.

RESULTS

Estimates of R0 for HAV infection ranged from 2.2 (95% confidence interval [CI], 1.9-2.5) for North Carolina to 5.0 (95% CI, 4.5-5.6) for West Virginia. Corresponding herd immunity thresholds ranged from 55% (95% CI, 47%-61%) for North Carolina to 80% (95% CI, 78%-82%) for West Virginia. Based on the meta-analysis, we estimated a pooled herd immunity threshold of 64% (95% CI, 61%-68%; 90% prediction interval, 52%-76%) among PWID. Using the prediction interval upper bound (76%) and assuming 95% vaccine efficacy, we estimated that vaccination coverage of 80% could prevent most HAV outbreaks.

CONCLUSIONS

Hepatitis A vaccination programs in the United States may need to achieve vaccination coverage of at least 80% among PWID in order to prevent most HAV outbreaks among this population.

Fixing a Hole: a retrospective cohort study evaluating HAV, HBV, tetanus screening, and vaccination during hospitalization in persons who use substances

Background

Rates of serious injection-related infections in persons who use drugs have increased. Resulting admissions are an opportunity for screening and vaccination of preventable infections such as hepatitis A virus (HAV), hepatitis B virus (HBV), and tetanus.

Design and methods

We conducted a retrospective review of adults with documented substance use admitted for bacterial infection between July 2015 and March 2020. We evaluated HAV, HBV, and tetanus vaccination status at admission, along with screening for HAV and HBV infection and immunity. We identified the proportion of patients at risk for infection who received HAV, HBV, and tetanus vaccines during admission and patient-level factors associated with vaccination.

Results

We identified 280 patients who met our inclusion criteria. Of the 198 (70.7%) patients at risk for HAV, infectious disease providers recommended vaccination for 21 (10.6%) and 15 (7.6%) received HAV vaccine. Of the 174 (62.1%) patients at risk for HBV, infectious disease providers recommended vaccination for 32 (18.3%) and 25 (14.4%) received HBV vaccine. A large proportion of patients (31.4%, 88) had no documentation of prior tetanus vaccination, and infectious disease providers recommended tetanus vaccination for three (1.1%) and five patients (1.8%) received a tetanus booster. Infectious disease consult vaccine recommendations were statistically significantly associated with HAV or HBV vaccination prior to discharge.

Conclusion

Over 70% of our population is at risk for one or more of these preventable infections. Efforts are needed to maximize inpatient screening and vaccination for HAV, HBV, and tetanus in patients with barriers to care.

Supporting syringe services programs in the initiation and scale-up of vaccine administration: findings from in-depth interviews

Background

Vaccine-hesitant persons who inject drugs are at increased risk for several vaccine-preventable diseases. However, vaccination rates among this population remain low. While syringe services programs (SSPs) are places where persons who inject drugs feel comfortable accessing services, few offer vaccination services. This study describes facilitators and barriers to vaccination at SSPs.

Methods

We used convenience sampling to conduct semi-structured, qualitative in-depth interviews with 21 SSPs in the USA from June to August 2021. Interview questions asked SSPs about their perceptions, priorities, barriers, facilitators, and the effects of partnerships and policies on vaccine administration. We used deductive thematic analysis to identify the main themes.

Results

Eight (n = 8) SSPs offered vaccinations, and thirteen (n = 13) did not offer vaccinations. Most SSPs believed offering vaccination services was important, although addressing SSP participants’ immediate needs often took precedence. Staffing, physical space, and logistical issues were the most common barriers to vaccine administration reported by SSPs, followed by SSP participant-related barriers. Facilitators of vaccine administration included access to a tracking system, partnering with agencies or other organizations providing vaccines, and having a licensed vaccination provider on-site. Partnerships provided SSPs opportunities to expand capacity but could also restrict how SSPs operate. Recommended policy changes to facilitate vaccine administration included subsidizing the cost of vaccinations and addressing restrictions around who could administer vaccinations.

Conclusions

Increasing the availability of vaccination services at SSPs requires addressing the varying capacity needs of SSPs, such as tracking systems, licensed vaccinators, and free or low-cost vaccination supplies. While these needs can be met through partnerships and supportive policies, both must consider and reflect cultural competence around the lived experiences of persons who inject drugs.

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.

Gaps in Hepatitis A and Hepatitis B Vaccination Among Hepatitis C Antibody-Positive Individuals Experiencing Homelessness

Vaccination for both hepatitis A (HAV) and hepatitis B (HBV) is recommended in hepatitis C infection (HCV). Among HCV antibody-positive persons experiencing homelessness, we identified high rates of HAV (34%) and HBV vaccine (35%) eligibility, highlighting critical gaps in HCV preventative services. Following education, 54% and 72% underwent HAV and HBV vaccination, respectively.