Understanding and addressing hepatitis C reinfection in the oral direct-acting antiviral era

Bridging the gap: Addressing disparities in hepatitis C screening, access to care, and treatment outcomes

Hepatitis C virus (HCV) is a significant public health challenge globally, with substantial morbidity and mortality due to chronic liver disease. Despite the availability of highly effective and well-tolerated direct-acting antiviral therapies, widespread disparities remain in hepatitis C screening, access to treatment, linkage to care, and therapeutic outcomes. This review article synthesizes evidence from various studies to highlight the multifactorial nature of these disparities, which affects ethnic minorities, people with lower socioeconomic status, individuals with substance use disorders, and those within correctional facilities. The review also discusses policy implications and targeted strategies needed to overcome barriers and ensure equitable care for all individuals with HCV. Recommendations for future research to address gaps in knowledge and evaluation of the effectiveness of interventions designed to reduce disparities are provided.

Update on Hepatitis C Vaccine: Results and Challenges

Therapy against the Hepatitis C virus (HCV) has significantly improved with the introduction of direct-acting antiviral drugs (DAAs), achieving over 95% sustained virological response (SVR). Despite this, the development of an effective anti-HCV vaccine remains a critical challenge due to the low number of patients treated with DAAs and the occurrence of HCV reinfections in high-risk groups. Current vaccine strategies aim to stimulate either B-cell or T-cell responses. Vaccines based on E1 and E2 proteins can elicit broad cross-neutralizing antibodies against all major HCV genotypes, though with varying efficiencies and without full protection against infection. In humans, the neutralizing antibodies induced by such vaccines mainly target the AR3 region, but their levels are generally insufficient for broad neutralization. Various HCV proteins expressed through different viral vectors have been utilized to elicit T cell immune responses, showing sustained expansion of HCV-specific effector memory T cells and improved proliferation and polyfunctionality of memory T cells over time. However, despite these advancements, the frequency and effectiveness of T-cell responses remain limited.

Success of the US Veterans Health Administration's Hepatitis C Virus Care Continuum in the Direct-acting Antiviral Era

BACKGROUND

Estimated hepatitis C prevalence within the Veterans Health Administration is higher than the general population and is a risk factor for advanced liver disease and subsequent complications. We describe the hepatitis C care continuum within the Veterans Health Administration 1 January 2014 to 31 December 2022.

METHODS

We included individuals in Veterans Health Administration care 2021-2022 who were eligible for direct-acting antiviral treatment 1 January 2014 to 31 December 2022. We evaluated the proportion of Veterans who progressed through each step of the hepatitis C care continuum, and identified factors associated with initiating direct-acting antivirals, achieving sustained virologic response, and repeat hepatitis C viremia.

RESULTS

We identified 133 732 Veterans with hepatitis C viremia. Hepatitis C treatment was initiated in 107 134 (80.1%), with sustained virologic response achieved in 98 136 (91.6%). In those who achieved sustained virologic response, 1097 (1.1%) had repeat viremia and 579 (52.8%) were retreated for hepatitis C. Veterans of younger ages were less likely to initiate treatment and achieve sustained virologic response, and more likely to have repeat viremia. Stimulant use and unstable housing were negatively associated with each step of the hepatitis C care continuum.

CONCLUSIONS

The Veterans Health Administration has treated 80% of Veterans with hepatitis C in care 2021-2022 and achieved sustained virologic response in more than 90% of those treated. Repeat viremia is rare and is associated with younger age, unstable housing, opioid use, and stimulant use. Ongoing efforts are needed to reach younger Veterans, and Veterans with unstable housing or substance use disorders.

Drug network identification predicts injecting risk behavior among people who inject drugs on hepatitis C virus treatment in Tayside, Scotland

The risk of Hepatitis C Virus (HCV) acquisition among People Who Inject Drugs (PWID) remains high when injecting risk behavior within networks endures. Several psychosocial factors influence such behavior. Following a drive within Tayside, a geographic region in Scotland, to achieve World Health Organization HCV elimination targets, addressing HCV re-infection risk as a barrier to elimination is critically important. This cross-sectional study seeks to address this barrier to elimination by investigating associations between group identification (one's subjective sense of belonging and connectedness to a social group coupled with a sense of shared goals, beliefs and values with the other members of the group) and injecting risk behavior among PWID on HCV treatment at needle and syringe provision sites in Tayside. Participants completed psychosocial questionnaires between treatment weeks zero and three of treatment. Correlation analyses were undertaken, and significant factors included in multiple linear regression models for injecting risk behavior. Injecting frequency, drug network identification, and family identification, were correlated with injecting risk behavior, and drug network identification had a positive predictive on injecting risk behavior. Identification with a social group, conventionally associated with improved health, may pose health risks in specific contexts. Healthcare providers should consider stratifying individuals with higher group identification with PWID networks for enhanced harm reduction engagement to mitigate transmissible infection risk among PWID. Additionally, psychological interventions to strengthen group identification with networks which impact positively on health behavior should be explored.

Hepatitis C virus reinfection incidence among gay and bisexual men with HIV in Australia from 2016 to 2020

BACKGROUND

There is some concern that hepatitis C virus (HCV) reinfection might impact HCV micro-elimination efforts among gay and bisexual men (GBM) with HIV. However, there is a limited understanding of reinfection incidence in the context of unrestricted government-funded HCV treatment. We aimed to estimate HCV reinfection incidence among GBM with HIV in Australia from 2016 to 2020.

METHODS

Data were from 39 clinics participating in ACCESS, a sentinel surveillance network for blood borne viruses and sexually transmissible infections across Australia. GBM with HIV who had evidence of treatment or spontaneous clearance with at least one positive HCV RNA test, a subsequent negative HCV RNA test, and at least one additional HCV RNA test between 1st January 2016 and 31st December 2020 were eligible for inclusion. A new HCV RNA positive test and/or detectable viral load was defined as a reinfection. Generalised linear modelling was used to examine trends in reinfection.

RESULTS

Among 12 213 GBM with HIV who had at least one HCV test, 540 were included in the reinfection incidence analysis, of whom 38 (7%) had evidence of reinfection during the observation period. Over 1124 person-years of follow-up, the overall rate of reinfection was 3.4/100PY (95% CI 2.5-4.6). HCV reinfection incidence declined on average 30% per calendar year (Incidence Rate Ratio 0.70, 95% CI 0.54-0.91).

CONCLUSION

HCV reinfection incidence has declined among GBM with HIV in Australia since government-funded unrestricted DAAs were made available. Ongoing HCV RNA testing following cure and prompt treatment for anyone newly diagnosed is warranted to sustain this.

Concerted synergy between viral-specific IgG and CD8 + T cells is critical for clearance of an HCV-related rodent hepacivirus

BACKGROUND AND AIMS

Evidence assessing the role of B cells and their antibodies, or lack thereof, in the spontaneous resolution of acute HCV infection is conflicting. Utilization of a strictly hepatotropic, HCV-related rodent hepacivirus (RHV) model circumvents many of the challenges facing the field in characterizing the immunological correlates of dichotomous infection outcomes. This study seeks to elucidate the importance of B cells in the clearance of acute RHV infection.

APPROACH AND RESULTS

µMT mice were infected i.v. with RHV and found to develop chronic infection for over a year. Wild-type (WT) mice depleted of B cells also exhibited persistent viremia that resolved only upon B cell resurgence. The persistent infection developed by B1-8i and AID cre/cre mice revealed that antigen-specific, class-switched B cells or their antibodies were crucial for viral resolution. Virus-specific CD8 + and CD4 + T cells were characterized in these mice using newly developed major histocompatibility complex class I and II tetramers and ex vivo peptide stimulation. Immunoglobulin G (IgG) was purified from the serum of RHV- or lymphocytic choriomeningitis virus Armstrong-infected mice after viral clearance and passively transferred to AID cre/cre recipients, revealing viral clearance only in αRHV IgG recipients. Further, the transfer of αRHV IgG into B cell-depleted recipients also induced viral resolution. This ability of RHV-specific IgG to induce viral clearance was found to require the concomitant presence of CD8 + T cells.

CONCLUSIONS

Our findings demonstrate a cooperative interdependence between immunoglobulins and the T cell compartment that is required for RHV resolution. Thus, HCV vaccine regimens should aim to simultaneously elicit robust HCV-specific antibody and T cell responses for optimal protective efficacy.

Determining reinfection rates by hepatitis C testing interval among key populations: A systematic review and meta-analysis

BACKGROUND & AIMS

Detecting hepatitis C virus (HCV) reinfection among key populations helps prevent ongoing transmission. This systematic review aims to determine the association between different testing intervals during post-SVR follow-up on the detection of HCV reinfection among highest risk populations.

METHODS

We searched electronic databases between January 2014 and February 2023 for studies that tested individuals at risk for HCV reinfection at discrete testing intervals and reported HCV reinfection incidence among key populations. Pooled estimates of reinfection incidence were calculated by population and testing frequency using random-effects meta-analysis.

RESULTS

Forty-one single-armed observational studies (9453 individuals) were included. Thirty-eight studies (8931 individuals) reported HCV reinfection incidence rate and were included in meta-analyses. The overall pooled estimate of HCV reinfection incidence rate was 4.13 per 100 per person-years (py) (95% confidence interval [CI]: 3.45-4.81). The pooled incidence estimate among people who inject drugs (PWID) was 2.84 per 100 py (95% CI: 2.19-3.50), among men who have sex with men (MSM) 7.37 per 100 py (95% CI: 5.09-9.65) and among people in custodial settings 7.23 per 100 py (95% CI: 2.13-16.59). The pooled incidence estimate for studies reporting a testing interval of ≤6 months (4.26 per 100 py; 95% CI: 2.86-5.65) was higher than studies reporting testing intervals >6 months (5.19 per 100 py; 95% CI: 3.92-6.46).

CONCLUSIONS

HCV reinfection incidence was highest in studies of MSM and did not appear to change with retesting interval. Shorter testing intervals are likely to identify more reinfections, help prevent onward transmission where treatment is available and enable progress towards global HCV elimination, but additional comparative studies are required.

Is HCV elimination among persons living with HIV feasible? Data from the NoCo study in the setting of the ICONA cohort

BACKGROUND AND AIMS

Whether the HCV test-and-treat strategy impacted on the rate of new HCV infections among PLWH in Italy is unknown.

METHODS

Prospective study of PLWH in the ICONA network. At baseline, PLWH were tested for HCV-Ab; HCV-RNA (if HCV-Ab positive) and, if positive, treated with DAA. SVR12 indicated eradication. Seroconversions and re-infections were evaluated yearly in HCV-Ab neg and HCV-RNA neg at first screening. We estimated the following: HCV seroconversions, incidence of HCV reinfections, and access to DAA and SVR12 rates tighter with factors associated with each outcome. Data were analysed by Cox regression, Poisson regression and logistic regression models.

RESULTS

Sixteen thousand seven hundred and forty-three PLWH were included; 27.3% HCV-Ab positive; of these, 39.3% HCV-RNA positive. HCV seroconversion incidence: .48/100 PYFU (95% CI: .36-.65); re-infections incidence: 1.40/100 PYFU (95% CI: .91-2.04). The risk factor for HCV re-infection was young age: aIRR 1.85, 95% CI: 1.17-2.95) per 10 years younger. 86.4% of HCV viremic in follow-up started DAA. PWID vs. heterosexuals (aHR .75, 95% CI .62-.90), HIV-RNA >50 copies/mL (aHR .70, 95% CI .56-.87), HCV genotype other than G1, G2, G3, G4 or with multiple/missing HCV genotype and post-COVID-19 calendar periods were associated with lower DAA access. 922/965 (95.5%) PLWH achieved SVR12. We estimated 72% reduction of chance to achieve SVR12 in PLWH with a CD4 count <200/mm3 (vs. CD4 ≥200/mm3 aOR .18, 95% CI: .07-.46). 95.5% of DAA-treated individuals eradicated HCV, but they represent only 53.2% of HCV viremic PLWH and 66.4% of those in follow-up. HCV-RNA positivity by year decreased from 41.7% in 2017 to 11.7% in 2022.

CONCLUSIONS

The screening-and-treat campaign implemented in Italy, even if only partially effective, resulted in a dramatic drop in HCV circulation in our cohort.

Chronic Hepatitis C Virus Infection: An Ongoing Challenge in Screening and Treatment

With the advent of direct-acting antiviral agents (DAA) in the recent few years, hepatitis C virus (HCV) infection has become a curable infectious disease. Successful clearance of HCV could lead to improvement of both hepatic and extrahepatic outcomes, such as complications of cirrhosis, hepatocellular carcinoma, cardiovascular diseases, and incident diabetes. However, challenges persist in reaching the HCV elimination goals of the World Health Organization by 2030. Among these challenges are identifying those already infected or undiagnosed subjects, re-linking to the care of known but untreated HCV-infected subjects, and developing strategies to enhance treatment rates and compliance in specific or high-risk populations. In addition, issues of post-DAA viral clearance, including avoiding or preventing reinfection in high-risk populations and surveillance of hepatocellular carcinoma, are important to consolidate the treatment's short- and long-term efficacies. In the current DAA era, treatment is the most effective prevention strategy not only in its excellent efficacy and safety but also in preventing HCV spread. All of the surveillance or measures should center on DAA treatment in clinical practice.

First Do No Harm? Modeling Risks and Benefits of Challenge Trials for Hepatitis C Vaccine Development

BACKGROUND

In 2019, about 58 million individuals were chronically infected with hepatitis C virus. Some experts have proposed challenge trials for hepatitis C virus vaccine development.

METHODS

We modeled incremental infections averted through a challenge approach, under varying assumptions regarding trial duration, number of candidates, and vaccine uptake. We computed the benefit-risk ratio of incremental benefits to risks for challenge versus traditional approaches. We also benchmarked against monetary costs of achieving incremental benefits through treatment.

RESULTS

Our base case assumes 3 vaccine candidates, each with an 11% chance of success, corresponding to a 30% probability of successfully developing a vaccine. Given this probability, and assuming a 5-year difference in duration between challenge and traditional trials, a challenge approach would avert an expected 185 000 incremental infections with 20% steady-state uptake compared to a traditional approach and 832 000 with 90% uptake (quality-adjusted life-year benefit-risk ratio, 72 000 & 323 000). It would cost at least $92 million and $416 million, respectively, to obtain equivalent benefits through treatment. BRRs vary considerably across scenarios, depending on input assumptions.

CONCLUSIONS

Benefits of a challenge approach increase with more vaccine candidates, faster challenge trials, and greater uptake.

Shorter Duration Hepatitis C Virus Treatment is Associated with Better Persistence to Prescription Refills in People Who Inject Drugs: A Real-World Study

INTRODUCTION

Direct-acting antiviral (DAA) therapy is highly effective in curing hepatitis C virus (HCV) infection in people who inject drugs (PWID). Previous studies showed declining persistence to DAA therapy over the course of treatment. This study compares real-world medication persistence to prescription refills for 8- versus 12-week DAA in treatment-naïve PWID with chronic HCV with compensated cirrhosis or without cirrhosis.

METHODS

Symphony Health's claims database was used to collect data from patients with chronic HCV aged ≥ 12 years who were prescribed 8- or 12-week DAA therapy between August 2017 and November 2020 and had a diagnosis of addicted drug use within 6 months prior to index date. Eligible patients had medical/pharmacy claims in the 6 months before and 3 months after the first index medication fill date (i.e., index date). Patients completing all refills (8-week = 1 refill, 12-week = 2 refills) were deemed persistent. The percentage of persistent patients in each group, and at each refill step, was determined; outcomes were also assessed in a subgroup of Medicaid-insured patients.

RESULTS

This study assessed 7203 PWID with chronic HCV (8-week, 4002; 12-week, 3201). Patients prescribed 8-week DAA treatment were younger (42.9 ± 12.4 vs 47.5 ± 13.2, P < 0.001) and had fewer comorbidities (P < 0.001). Patients receiving 8- versus 12-week DAA had greater refill persistence (87.9% vs 64.4%, P < 0.001). Similar percentages of patients missed their first refill (8-week, 12.1% vs 12-week, 10.8%); nearly 25% of patients receiving 12-week DAA missed their second refill. After baseline characteristics were controlled, patients prescribed 8- versus 12-week DAA were more likely to be persistent (odds ratio [95% confidence interval] 4.3 [3.8, 5.0]). Findings in the Medicaid-insured subgroup were consistent.

CONCLUSION

Patients prescribed 8- vs 12-week DAA therapy had significantly greater prescription refill persistence. Most nonpersistence was due to missed second refills, highlighting the potential benefit of shorter treatment durations in this population.

Investigating rates and risk factors for hepatitis C virus reinfection in people receiving antiviral treatment in England

England has committed to the World Health Organization target to eliminate hepatitis C virus (HCV) as a public threat by the year 2030. Given successful treatments for HCV in recent years, it is unclear whether HCV reinfection will impact England's ability to achieve HCV elimination. We aimed to estimate the HCV reinfection rate among a cohort of patients receiving antiviral treatment using available surveillance data. Linkage between a treatment dataset from 2015 to 2019 and an HCV RNA testing dataset were used to identify people who experienced reinfection using three criteria. A Cox proportional hazards model was used to determine risk factors associated with HCV reinfection among a cohort who received treatment and had follow-up HCV RNA testing. The reinfection rate among those receiving HCV treatment was 7.91 per 100 person-years (PYs, 95% confidence interval (CI) 7.37-8.49) and highest among current injecting drug users (22.55 per 100 PYs, 95% CI 19.98-25.46) and people who had been in prison (20.42 per 100 PYs, 95% CI 17.21-24.24). In the adjusted model, women had a significantly reduced risk of reinfection. Being of younger age, current injecting drug users, and receipt of first treatment in prison were each significantly associated with increased risk of reinfection. Two-fifths of those with reinfection (43%, n = 329/767) were linked to treatment after reinfection, and of those starting treatment, three quarters (75%, n = 222/296) achieved a sustained virologic response. Guidance for testing groups at risk of reinfection and harm reduction strategies to minimize transmission should be implemented if England is to achieve HCV elimination targets.

Public reimbursement policies in Canada for direct-acting antiviral treatment of hepatitis C virus infection: A descriptive study

Background

Direct-acting antiviral (DAA) therapies have simplified HCV treatment, and publicly funded Canadian drug plans have eliminated disease-stage restrictions for reimbursement of DAA therapies. However other policies which complicate, delay, or prevent treatment initiation still persist. We aim to describe these plans' existing reimbursement criteria and appraise whether they hinder treatment access.

Methods

We reviewed DAA reimbursement policies of 16 publicly funded drug plans published online and provided by contacts with in-depth knowledge of prescribing criteria. Data were collected from May to July 2022. Primary outcomes were: (1) if plans have arranged to accept point-of-care HCV RNA testing for diagnosis; testing requirements for (2) HCV genotype, (3) fibrosis stage, and (4) chronic infection; (5) time taken and method used to approve reimbursement requests; (6) providers eligible to prescribe DAAs; and (7) restrictions on re-treatment.

Results

Fifteen (94%) plans have at least one policy in place which limits simplified HCV treatment. Many plans continue to require results of genotype or fibrosis staging, limit eligible prescribers, and take longer than 1 day to approve coverage requests. One plan discourages treatment for re-infection.

Conclusion

Reimbursement criteria set by publicly funded Canadian drug plans continue to limit timely, equitable access to HCV treatment. Eliminating clinically irrelevant pre-authorization testing, expanding eligible prescribers, expediting claims processing, and broadening coverage of treatment for reinfection will improve access to DAAs. The federal government could further enhance efforts by introducing a federal HCV elimination strategy or federal high-cost drug PharmaCare program.

The rate of hepatitis C reinfection in Canadians coinfected with HIV and its implications for national elimination

BACKGROUND

The World Health Organisation (WHO) has set targets for the rate of new infections as a way to measure progress towards the elimination of hepatitis C virus (HCV) as a public health threat. As more people are successfully treated for HCV, a higher proportion of new infections will be reinfections. We consider whether the reinfection rate has changed since the interferon era and what we can infer about national elimination efforts from the current reinfection rate.

METHODS

The Canadian Coinfection Cohort is representative of HIV HCV coinfected people in clinical care. We selected cohort participants successfully treated for a primary HCV infection either in the interferon era or in the era of direct acting antivirals (DAAs). Selected participants were followed from 12 weeks after completing a successful treatment until the end of 2019 or until their last measured HCV RNA. We estimated the reinfection rate in each treatment era, overall and in participant subgroups, using proportional hazard models appropriate for interval censored data.

RESULTS

Among 814 successfully treated participants with additional HCV RNA measurements, there were 62 reinfections. The overall reinfection rate was 2.6 (95% confidence interval, CI, 1.2-4.1) /100 person years (PY) in the interferon era and 3.4 (95% CI 2.5-4.4) /100 PY in the DAA era. The rate in those reporting injection drug use (IDU) was much higher: 4.7 (95% CI 1.4-7.9) /100 PY and 7.6 (95% CI 5.3-10) /100 PY in the interferon and DAA eras respectively.

CONCLUSION

The overall reinfection rate in our cohort is now above the WHO target set for new infections in people who inject drugs. The reinfection rate in those reporting IDU has increased since the interferon era. This suggests Canada is not on track to achieve HCV elimination by 2030.

Economic Impact of Universal Hepatitis C Virus Testing for Middle-Aged Adults Who Inject Drugs

INTRODUCTION

The objective of this study was to estimate the economic impact of providing universal hepatitis C virus testing in commercially insured middle-aged persons who inject drugs in the U.S.

METHODS

This study developed a dynamic 10-year economic model to project the clinical and economic outcomes associated with hepatitis C virus testing among middle-aged adult persons who inject drugs, from a payer's perspective. Costs related to hepatitis C virus testing, direct-acting antiviral, and liver-related outcomes between the (1) current hepatitis C virus testing rate (i.e., 8%) and (2) universal hepatitis C virus testing rate (i.e., 100%) were compared. Among patients testing positive, 21% of those without cirrhosis and 48% of those with cirrhosis were assumed to initiate direct-acting antivirals. Sensitivity analyses were performed to identify variables (e.g., direct-acting antiviral drug costs, hepatitis C virus testing costs, direct-acting antiviral treatment rate) influencing this study's conclusion.

RESULTS

The model predicts that during the 10-year period, universal hepatitis C virus testing will cost an additional $242 per person who injects drugs to the payers' healthcare budgets compared with the current scenario. Sensitivity analyses showed values ranging from $1,656 additional costs to $1,085 cost savings across all varied parameters and scenarios. A total of 80% of the current direct-acting antiviral costs indicated that cost savings will be $383 per person who injects drugs.

CONCLUSIONS

Universal hepatitis C virus testing among persons who inject drugs would not achieve cost savings within 10 years, with the cost of direct-acting antivirals contributing the most to the spending. To promote universal hepatitis C virus testing among persons who inject drugs, decreasing direct-acting antiviral costs and sustainable funding streams for hepatitis C virus testing should be considered.

Another Step Toward Hepatitis C Elimination: An Economic Evaluation of an Irish National Birth Cohort Testing Program

OBJECTIVES

We aimed to evaluate the cost-effectiveness of offering once-off birth cohort testing for hepatitis C virus (HCV) to people in Ireland born between 1965 and 1985, the cohort with the highest reported prevalence of undiagnosed chronic HCV infection.

METHODS

Systematic and opportunistic HCV birth cohort testing programs, implemented over a 4-year timeframe, were compared with the current practice of population risk-based testing only in a closed-cohort decision tree and Markov model hybrid over a lifetime time horizon. Outcomes were expressed in quality-adjusted life-years (QALYs). Costs were presented from the health system's perspective in 2020 euro (€). Uncertainty was assessed via deterministic, probabilistic, scenario, and threshold analyses.

RESULTS

In the base case, systematic testing yielded the largest cost and health benefits, followed by opportunistic testing and risk-based testing. Compared with risk-based testing, the incremental cost-effectiveness ratio for opportunistic testing was €14 586 (95% confidence interval €4185-€33 527) per QALY gained. Compared with opportunistic testing, the incremental cost-effectiveness ratio for systematic testing was €16 827 (95% confidence interval €5106-€38 843) per QALY gained. These findings were robust across a range of sensitivity analyses.

CONCLUSIONS

Both systematic and opportunistic birth cohort testing would be considered an efficient use of resources, but systematic testing was the optimal strategy at willingness-to-pay threshold values typically used in Ireland. Although cost-effective, any decision to introduce birth cohort testing for HCV (in Ireland or elsewhere) must be balanced with considerations regarding the feasibility and budget impact of implementing a national testing program given high initial costs and resource use.

Integrated care model and point of care diagnostics facilitate Hepatitis C treatment among patients receiving opioid agonist therapy: a retrospective review of medical records

Background

Hepatitis C virus (HCV) is common among individuals in opioid agonist therapy (OAT). HCV treatment has previously been unavailable for most HCV positive OAT patients in Finland. The removal of treatment restrictions and attempts to reach HCV elimination goals have increased the number of OAT patients needing HCV treatment. The objectives of this study were 1) to characterize Finnish HCV positive OAT patients and evaluate their eligibility for HCV treatment at addiction service units, and 2) to retrospectively review the outcomes of treated patients.

Methods

The study focused on HCV positive OAT patients (n = 235). Demographics and clinical parameters were retrospectively reviewed using the patients’ medical records. The eligibility of providing HCV treatment to patients at addiction service units were evaluated based on patients’ clinical characteristics, such as liver function and patterns of substance use. The outcomes of patients receiving HCV treatment were reviewed.

Results

Of HCV antibody positive OAT patients, 75% had chronic HCV. Of 103 HCV patients screened for liver fibrosis either with Fibroscan or APRI (aspartate aminotransferase to platelet ratio index), 83 patients (81%) had no indication of severe liver damage. Point of care (POC) HCV tests were used for 46 patients to lower the threshold of attending laboratory testing. All patients preferred POC testing to conventional blood testing.

Twenty patients had received HCV treatment, 19 completed the treatment and achieved sustained virologic response (SVR) at the end of the treatment. Of the 18 patients available for evaluation of SVR at 12 weeks after the treatment (SVR12), 17 achieved SVR12.

Conclusions

The integrated model consisting of HCV diagnostics and treatment at the addiction service unit was successfully implemented within normal OAT practice.

In a Real-Life Setting, Direct-Acting Antivirals to People Who Inject Drugs with Chronic Hepatitis C in Turkey

BACKGROUND

People who inject drugs (PWID) should be treated in order to eliminate hepatitis C virus in the world. The aim of this study was to compare direct-acting antivirals treatment of hepatitis C virus for PWID and non-PWID in a real-life setting.

METHODS

We performed a prospective, non-randomized, observational multicenter cohort study in 37 centers. All patients treated with direct-acting antivirals between April 1, 2017, and February 28, 2019, were included. In total, 2713 patients were included in the study among which 250 were PWID and 2463 were non-PWID. Besides patient characteristics, treatment response, follow-up, and side effects of treatment were also analyzed.

RESULTS

Genotype 1a and 3 were more prevalent in PWID-infected patients (20.4% vs 9.9% and 46.8% vs 5.3%). The number of naïve patients was higher in PWID (90.7% vs 60.0%), while the number of patients with cirrhosis was higher in non-PWID (14.1% vs 3.7%). The loss of follow-up was higher in PWID (29.6% vs 13.6%). There was no difference in the sustained virologic response at 12 weeks after treatment (98.3% vs 98.4%), but the end of treatment response was lower in PWID (96.2% vs 99.0%). In addition, the rate of treatment completion was lower in PWID (74% vs 94.4%).

CONCLUSION

Direct-acting antivirals were safe and effective in PWID. Primary measures should be taken to prevent the loss of follow-up and poor adherence in PWID patients in order to achieve World Health Organization's objective of eliminating viral hepatitis.

Direct-acting antiviral retreatment patterns for hepatitis C

BACKGROUND: Despite the strong efficacy of direct-acting antivirals (DAAs) against the hepatitis C virus, many patients require a second regimen of DAA treatment. However, limited research exists to characterize rates of retreatment across different DAA agents or potential factors that may increase retreatment risk. OBJECTIVE: To characterize patterns and predictors of DAA retreatment among a large, generalizable, commercially insured US population of patients. METHODS: Using the IBM MarketScan Commercial Claims and Encounters data source, this retrospective cohort study examined retreatment patterns among patients receiving DAAs between 2013 and 2019. Descriptive statistics were used to compare patient characteristics predictive of retreatment risk and to examine rates of retreatment in patients initiating different DAA treatments. RESULTS: Among 31,553 DAA users, a total of 1,017 (3.2%) required DAA retreatment. Among the 1,017 patients re-treated, 44 (4.3%) received a third treatment regimen and 2 patients received a fourth treatment regimen. The average total cost for a retreatment regimen was $109,683, with patient out-of-pocket costs totaling $1,287 Patients requiring retreatment had higher rates of hypertension (32.0% vs 26.7%; P < 0.001), diabetes (16.9% vs 11.9%; P < 0.001), coagulopathy (9.9% vs 4.5%; P < 0.001), deficiency anemia (11.1% vs 7.4%; P < 0.001), alcohol abuse (3.3% vs 2.3%; P = 0.038), prior liver transplantation (3.4% vs 2.3%; P = 0.024), and hepatocellular carcinoma (6.1% vs 1.9%; P < 0.001) compared with patients not requiring retreatment. CONCLUSIONS: Although uncommon, some patients receiving DAAs require a second regimen of DAA treatment at substantial cost to both health plans and patients. These patients tend to have more comorbidities and markers of hepatic disease severity. Patients with high retreatment risk may benefit from careful monitoring for occurrences of retreatment.

HCV microelimination in harm reduction centres has benefits beyond HCV cure but is hampered by high reinfection rates

Background & Aims

Significant scale-up of treatment among people who inject drugs (PWID) is crucial to achieve WHO HCV elimination targets. We explored the impact of on-site HCV diagnosis and treatment on PWID in an externalised hepatology clinic at the biggest harm reduction centre (HRC) in Barcelona attending to a marginalised PWID population with ongoing high-risk practices.

Methods

On-site HCV point-of-care testing was performed for diagnosis and treatment delivery. HCV-RNA was assessed at SVR12 (sustained virologic response at 12 weeks) and every 6 months. The programme included behavioural questionnaires at baseline and after treatment.

Results

Between 2018 and 2020, 919 individuals were prospectively enrolled. Of these, only 46% accepted HCV screening. HCV-RNA+ prevalence was 55.7% (n = 234). Of the 168 (72%) individuals starting treatment, 48% were foreigners, 32% homeless, 73% unemployed, and 62% had a history of incarceration. At enrolment, 70% injected drugs daily and 30% reported sharing needles or paraphernalia. Intention-to-treat SVR12 was 60%; only 4% were virological failures, the remaining were either early reinfections (20%) or losses to follow-up (16%). The overall reinfection rate during follow-up was 31/100 persons/year. HIV coinfection and daily injection were associated with a higher risk of reinfection. Nonetheless, beyond viral clearance, antiviral therapy was associated with a significant reduction in injection frequency, risk practices, and homelessness.

Conclusions

HCV treatment can be successfully delivered to active PWID with high-risk practices and has a significant benefit beyond HCV elimination. However, approaching this difficult spectrum of the PWID population implies significant barriers such as low rate of screening acceptance and high dropout and reinfection rates.

Lay summary

People who inject drugs attending harm reduction centres represent the most difficult population to treat for hepatitis C. We show that hepatitis C treatment has a significant benefit beyond viral cure, including improving quality of life, and decreasing injection frequency and risk practices. However, intrinsic barriers and the high reinfection rates hamper the achievement of viral microelimination in this setting.

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HCV treatment can be successfully delivered to active PWID with high-risk practices.

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HCV treatment has benefits beyond sustained virological response.

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PWID reported lower injection frequency and risk practices after engaging in the HCV programme.

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However, linkage-to-care for PWID attending harm reduction centres is challenging.

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The high dropout and reinfection rates hamper HCV microelimination in this population.

Country versus pharmaceutical company interests for hepatitis C treatment

Hepatitis C virus (HCV) is one of the leading causes of liver disease and is responsible for massive health and economic burden worldwide. The disease is asymptomatic in its early stages, but it can progress over time to fatal end-stage liver disease. Thus, the majority of individuals infected with HCV are unaware of their chronic condition. Recent treatment options for HCV can completely cure the infection but are costly. We developed a game model between a pharmaceutical company (PC) and a country striving to maximize its citizens' utility. First, the PC determines the price of HCV treatment; then, the country responds with corresponding screening and treatment strategies. We employed an analytical framework to calculate the utility of the players for each selected strategy. Calibrated to detailed HCV data from Israel, we found that the PC will gain higher revenue by offering a quantity discount rather than using standard fixed pricing per treatment, by indirectly forcing the country to conduct more screening than it desired. By contrast, risk-sharing agreements, in which the country pays only for successful treatments are beneficial for the country. Our findings underscore that policy makers worldwide should prudently consider recent offers by PCs to increase screening either directly, via covering HCV screening, or indirectly, by providing discounts following a predetermined volume of sales. More broadly, our approach is applicable in other healthcare settings where screening is essential to determine treatment strategies.

Development and pilot-testing of a hepatitis C reinfection prevention intervention for patients in treatment for hepatitis C infection

•We developed a two-session behavioral intervention to prevent HCV reinfection.•The intervention was piloted at an OTP and integrated into HCV treatment.•Baseline data showed limited knowledge & application of safer injection practices.•Implementation barriers included logistics and the lack of financial incentive.•Adaptations addressed barriers, yielding a more feasible and acceptable intervention.

Detection of Recurrent Hepatitis C Viremia Using Surveillance Data, New York City

The introduction of direct-acting antivirals for treating hepatitis C virus (HCV) infection has greatly improved cure rates. However, persons with past HCV infection who engage in high-risk behaviors can be reinfected. Surveillance data from the New York City (NYC) Health Department were used to detect and investigate individuals cured during January 2014 to December 2016 who had a subsequent positive RNA test (recurrence) by April 2018. Clinical interpretation of recurrence was obtained using provider interviews and review of medical records available through Regional Health Information Organizations. Among 6938 cured individuals, 209 recurrence events were detected (2.7 per 100 person-years). Investigations were completed for 62 (30%) events. Of 38 investigated events occurring less than 12 months postcure, 17 (45%) were relapses; of 24 events occurring 12 or more months postcure, only one (4%) was a relapse. Understanding the timing, frequency, and clinical interpretation of HCV recurrence will guide HCV prevention and elimination efforts for NYC.

Virus-Like Particles Containing the E2 Core Domain of Hepatitis C Virus Generate Broadly Neutralizing Antibodies in Guinea Pigs

A vaccine to prevent hepatitis C virus (HCV) infection is urgently needed for use alongside direct-acting antiviral drugs to achieve elimination targets. We have previously shown that a soluble recombinant form of the glycoprotein E2 ectodomain (residues 384 to 661) that lacks three variable regions (Δ123) is able to elicit a higher titer of broadly neutralizing antibodies (bNAbs) than the parental form (receptor-binding domain [RBD]). In this study, we engineered a viral nanoparticle that displays HCV glycoprotein E2 on a duck hepatitis B virus (DHBV) small surface antigen (S) scaffold. Four variants of E2-S virus-like particles (VLPs) were constructed: Δ123-S, RBD-S, Δ123A7-S, and RBDA7-S; in the last two, 7 cysteines were replaced with alanines. While all four E2-S variant VLPs display E2 as a surface antigen, the Δ123A7-S and RBDA7-S VLPs were the most efficiently secreted from transfected mammalian cells and displayed epitopes recognized by cross-genotype broadly neutralizing monoclonal antibodies (bNMAbs). Both Δ123A7-S and RBDA7-S VLPs were immunogenic in guinea pigs, generating high titers of antibodies reactive to native E2 and able to prevent the interaction between E2 and the cellular receptor CD81. Four out of eight animals immunized with Δ123A7-S elicited neutralizing antibodies (NAbs), with three of those animals generating bNAbs against 7 genotypes. Immune serum generated by animals with NAbs mapped to major neutralization epitopes located at residues 412 to 420 (epitope I) and antigenic region 3. VLPs that display E2 glycoproteins represent a promising vaccine platform for HCV and could be adapted to large-scale manufacturing in yeast systems.

IMPORTANCE There is currently no vaccine to prevent hepatitis C virus infection, which affects more than 71 million people globally and is a leading cause of progressive liver disease, including cirrhosis and cancer. Broadly neutralizing antibodies that recognize the E2 envelope glycoprotein can protect against heterologous viral infection and correlate with viral clearance in humans. However, broadly neutralizing antibodies are difficult to generate due to conformational flexibility of the E2 protein and epitope occlusion. Here, we show that a VLP vaccine using the duck hepatitis B virus S antigen fused to HCV glycoprotein E2 assembles into virus-like particles that display epitopes recognized by broadly neutralizing antibodies and elicit such antibodies in guinea pigs. This platform represents a novel HCV vaccine candidate amenable to large-scale manufacture at low cost.

Emergence of Hepatitis C Virus Genotype 2c Infection Among Human Immunodeficiency Virus-Infected Men Who Have Sex With Men in Tokyo, Japan

ABSTRACT

We report on hepatitis C virus genotype 2c infection in 12 human immunodeficiency virus-infected men who have sex with men in Tokyo, Japan. The uncommon strains from the 12 patients were genetically clustered; they suggested an emerging outbreak in this population at high risk of sexually transmitted infections.

Hepatitis C reinfection by treatment pathway among people who inject drugs in Tayside, Scotland

The efficacy of direct-acting antivirals (DAA) provides an excellent opportunity to scale up HCV diagnosis and treatment, achieving the WHO target of HCV elimination by 2030. However, HCV reinfection among people who inject drugs (PWID) remains a concern and may impede elimination efforts. We assessed reinfection rates among PWID across six specialized treatment pathways, following DAA-based and interferon-based therapies in Tayside, Scotland. Data were collected retrospectively for every treatment episode that resulted in a sustained viral response (SVR) after undergoing treatment. Reinfection rates were calculated for each treatment pathway: hospital outpatient clinic; community pharmacy; drug treatment outreach; prison clinic; nurse-led outreach clinic; and injection equipment provision site. Reinfection is defined as a positive RNA test result after SVR. Incidences of reinfection are expressed in 100 person-years (PYs). In total, 916 treatment episodes met selection criteria. Of these, 100 reinfections were identified, generating an overall reinfection rate of 5.27 per 100 PYs (95%CI: 4.36-6.38). The hospital outpatient clinic had the lowest reinfection incidence (1.81 per 100 PYs, 95%CI: 1.11-2.93), with the injection equipment provision site treatment pathway having the highest reinfection incidence (19.89 per 100 PYs, 95%CI: 14.91-26.54). The incidence of reinfection among those treated with interferon-based therapies and those treated with DAA-based therapies was 4.93 per 100 PYs (95%CI: 3.97-6.11) and 7.17 per 100 PYs (95%CI: 4.75-10.82), respectively. Specialized treatment pathways in Tayside yield varying reinfection incidence rates, with different subpopulations of patients at varying risk of reinfection post-SVR. Results suggest that resources should be targeted at the injection equipment provision site pathway in order to reduce the incidence of reinfection and achieve elimination targets. The study found comparable rates of reinfection following interferon-based and DAA-based therapies, providing support for widening access to treatment services.

Real-life experience of treating HCV co-infection among HIV-infected population in Egypt: single-center experience

BACKGROUND

Liver disease has emerged as a leading cause of death among PLHIV coinfected with HCV.

METHODS

A retrospective study involving all HCV viremic patients coinfected with HIV who presented to HCV/HIV multidisciplinary clinics located at Embaba fever hospital. Patients were assigned to receive DAAs according to the national treatment guidelines. The primary endpoint was SVR12.

RESULTS

Of the 519 patients enrolled, 38.73% LTFU; either not initiated (n = 170) or did not complete the treatment (n = 31). The main identified reasons behind LTFU were schedule conflict (19%) or hospitalization (13%). Among 318 patients who completed their DAAs course, nine patients had a relapse after the end of treatment and 97% had attained SVR12. There were significant differences among different virological response groups in baseline factors including smoking (p = 0.005), history of dental procedure (p = 0.007), CD4 count (p = 0.007), and HIV viral load (p = <0.001). Among responders (n = 309), there was a significant reduction of baseline hemoglobin and significant improvement of baseline platelets (p = 0.005) at on-treatment week 8. Baseline necro-inflammatory markers showed significant improvement across follow-up time points (p < 0.001).

CONCLUSIONS

DAAs are an effective and safe choice to treat HCV in PLHIV. Social stigma could be a major cause for lacking adherence to follow-up visits.Abbreviations: ALT: Alanine Aminotransferase; ARV: Antiretroviral treatment; AST: Aspartate Aminotransferase; DAAs: Direct acting antivirals; ARVs: antiretroviral therapy; EMR: Eastern Mediterranean region; HCV: Hepatitis C virus; kPa: Kilopascal; LTFU: Patient lost to follow up; NCCVH: The National Committee for Control of Viral Hepatitis; PWID: People who inject drugs; SVR: Sustained virological response;UNAIDS: The Joint United Nations Programme on HIV/AIDS.

Reinfection following successful direct-acting antiviral therapy for HCV infection among people attending an inner-city community health centre in Victoria, Canada

BACKGROUND

Studies of HCV reinfection following direct-acting antiviral (DAA) therapy among PWID have been limited by short follow-up and small case numbers. This study evaluated the incidence of HCV reinfection following successful DAA therapy among people attending an inner-city community health centre in Victoria, Canada.

METHODS

In this observational study, participants treated with DAA therapy between November 2014 and December 31, 2019 were included. Retrospective chart review was performed to assess demographics, recent injecting drug use at treatment initiation (previous six months), opioid agonist treatment (OAT), and HIV. Endpoints included sustained virologic response (SVR), HCV reinfection, and mortality.

RESULTS

Of 482 participants initiating DAA treatment, 30% were female, 46% were receiving OAT, 49% had recent injection drug use, 15% had HIV/HCV coinfection, and 22% had cirrhosis. Treatment completion was 97% (468/482; 12 discontinued therapy, and 2 died during treatment). SVR was 87% (418/482). Outcomes among those who completed treatment but did not achieve SVR (n=53), included loss to follow-up (n=11), HCV RNA for SVR testing not completed (n=18), viral relapse (n=6), reinfection (n=5) and viral recurrence (n=5, unable to distinguish viral relapse from reinfection), and death (n=7). The rate of HCV reinfection was 3.6/100 person-years (95% confidence interval [CI] 2.4-5.5; 22 cases; 602 person-years follow-up). Factors associated with an increased risk of HCV reinfection included recent injection drug use (adjusted relative risk [aRR] 8.55, 95% CI 1.98-36.96) and HIV co-infection (aRR 2.35, 95% CI 1.01-5.44). Fifty-five people died (overdose, n=19) during (n=2) or following (n=53) therapy (7.4/100 person-years; 95% CI 5.6-9.6).

CONCLUSION

This study demonstrates ongoing reinfection among a marginalized population at an inner-city community health centre, with higher rates among those with HIV and recent injecting drug use. The rates of reinfection and mortality highlight the importance of integrating HCV care with strategies to address drug-related harms.

Phylogenetic analysis in the clinical risk management of an outbreak of hepatitis C virus infection among transfused thalassaemia patients in Italy

BACKGROUND

Occurrence of hepatitis C virus (HCV) infection is reduced by effective risk management procedures, but patient-to-patient transmission continues to be reported in healthcare settings.

AIM

To report the use of phylogenetic analysis in the clinical risk management of an HCV outbreak among 128 thalassaemia outpatients followed at a thalassaemia centre of an Italian hospital.

METHODS

Epidemiological investigation and root-cause analysis were performed. All patients with acute hepatitis and known chronic infection were tested for HCV RNA, HCV genotyping, and NS3, NS5A, and NS5B HCV genomic region sequencing. To identify transmission clusters, phylogenetic trees were built for each gene employing Bayesian methods.

FINDINGS

All patients with acute hepatitis were infected with HCV genotype 1b. Root-cause analysis, including a lookback procedure, excluded blood donors as the source of HCV transmission. The phylogenetic analysis, conducted on seven patients with acute infection and eight patients with chronic infection, highlighted four transmission clusters including at least one patient with chronic and one patient with acute HCV infection. All patients in the same cluster received a blood transfusion during the same day. Two patients with acute hepatitis spontaneously cleared HCV within four weeks and nine patients received ledipasvir plus sofosbuvir for six weeks, all achieving a sustained virological response.

CONCLUSION

Combined use of root-cause analysis and molecular epidemiology was effective in ascertaining the origin of the HCV outbreak. Antiviral therapy avoided the chronic progression of the infection and further spread in care units and in the family environment.

Elimination of hepatitis C among HIV-positive population in Asia: old and new challenges

Hepatitis C virus (HCV) prevalence is high among people living with HIV co-infected with HCV, people who inject drugs, men who have sex with men and inmates in correctional settings. The barriers to eliminate HCV among these key populations include diagnosis challenges, lack of awareness, discrimination and stigmatization. In addition, scaling up of HCV treatment has been a challenge in Asia–Pacific with the lack of national policies, targets and unavailability of appropriate direct-acting antivirals regimens. In order to achieve HCV micro elimination within these high-risk populations, novel strategies to improve the cascade of care from diagnosis to treatment with direct-acting antivirals, complemented by behavioral change interventions, harm reduction services for people who inject drugs, civil society led advocacy and policies from the government, will be necessary.

Reciprocal Inhibition of Immunogenic Performance in Mice of Two Potent DNA Immunogens Targeting HCV-Related Liver Cancer

Chronic HCV infection and associated liver cancer impose a heavy burden on the healthcare system. Direct acting antivirals eliminate HCV, unless it is drug resistant, and partially reverse liver disease, but they cannot cure HCV-related cancer. A possible remedy could be a multi-component immunotherapeutic vaccine targeting both HCV-infected and malignant cells, but also those not infected with HCV. To meet this need we developed a two-component DNA vaccine based on the highly conserved core protein of HCV to target HCV-infected cells, and a renowned tumor-associated antigen telomerase reverse transcriptase (TERT) based on the rat TERT, to target malignant cells. Their synthetic genes were expression-optimized, and HCV core was truncated after aa 152 (Core152opt) to delete the domain interfering with immunogenicity. Core152opt and TERT DNA were highly immunogenic in BALB/c mice, inducing IFN-γ/IL-2/TNF-α response of CD4+ and CD8+ T cells. Additionally, DNA-immunization with TERT enhanced cellular immune response against luciferase encoded by a co-delivered plasmid (Luc DNA). However, DNA-immunization with Core152opt and TERT mix resulted in abrogation of immune response against both components. A loss of bioluminescence signal after co-delivery of TERT and Luc DNA into mice indicated that TERT affects the in vivo expression of luciferase directed by the immediate early cytomegalovirus and interferon-β promoters. Panel of mutant TERT variants was created and tested for their expression effects. TERT with deleted N-terminal nucleoli localization signal and mutations abrogating telomerase activity still suppressed the IFN-β driven Luc expression, while the inactivated reverse transcriptase domain of TERT and its analogue, enzymatically active HIV-1 reverse transcriptase, exerted only weak suppressive effects, implying that suppression relied on the presence of the full-length/nearly full-length TERT, but not its enzymatic activity. The effect(s) could be due to interference of the ectopically expressed xenogeneic rat TERT with biogenesis of mRNA, ribosomes and protein translation in murine cells, affecting the expression of immunogens. HCV core can aggravate this effect, leading to early apoptosis of co-expressing cells, preventing the induction of immune response.

We Must Do Better: Addressing HCV Treatment Barriers in Persons Who Inject Drugs in the United States

The opioid epidemic in the United States, along with a lack of adequate harm reduction services, has contributed to a sharp rise in hepatitis C virus (HCV) infections. Despite considerable evidence of the effectiveness of HCV treatment in people who inject drugs (PWID), and recommendations from clinical guidelines to prioritize treatment in PWID, there are multiple barriers to broad uptake of HCV treatment. These barriers exist at the systems level, as well as at the level of medical providers and patients. Interventions to remove treatment barriers in the United States include harm reduction services, simplifying HCV testing algorithms, improved linkage to HCV care services, and application of new treatment models including colocating services at substance use disorder treatment programs. By following the lead of other countries who have addressed the barriers to HCV treatment, the United States has opportunities to do better in addressing the consequences of the opioid epidemic, including chronic HCV infection.

Allocating treatment resources for hepatitis C in the UK: a constrained optimization modelling approach

Background and objective: Although the treatment of chronic hepatitis C (CHC) has significantly evolved with the introduction of direct-acting antivirals, the treatment uptake rates have been low especially among marginalized groups in the UK, such as people who inject drug (PWID) and men who have sex with men (MSM). Cutting health inequality is a major focus of healthcare agencies. This study aims to identify the optimal allocation of treatment budget for chronic hepatitis CHC among populations and treatments in the UK so that liver-related mortality in patients with CHC is minimized, given the constraint of treatment budget and equity issue. Methods: A constrained optimization modelling of resource allocation for the treatment of CHC was developed in Excel from the perspective of the UK National Health System over a lifetime horizon. The model was designated with the objective function of minimizing liver-related deaths by varying the decision variables, representing the number of patients receiving each treatment (elbasvir-grazoprevir, ombitasvir-paritaprevir-ritonavir-dasabuvir, sofosbuvir-ledipasvir, and pegylated interferon-ribavirin) in each population (the general population, PWID, and MSM). Two main constraints were formulated including treatment budget and the issue of equity. The model was populated with UK local data applying linear programming and underwent internal and external validation. Scenario analyses were performed to assess the robustness of model results. Results: Within the constraints of no additional funding over original spending in status quo and the consideration of the issue of equity among populations, the optimal allocation from the constrained optimization modelling (treating 13,122 PWID, 160 MSM, and 904 general patients with ombitasvir-paritaprevir-ritonavir-dasabuvir) was found to treat 2,430 more patients (relative change: 20.7%) and avert 78 liver-related deaths (relative change: 0.3%) compared with the current allocation. The number of patients receiving treatment increased 4,928 (relative change: 60.1%) among PWID and 42 (relative change: 35.8%) among MSM. Conclusion: The current allocation of treatment budget for CHC is not optimal in the UK. More patients would be treated, and more liver-related deaths would be avoided using a new allocation from a constrained optimization modelling without incurring additional spending and considering the issue of equity.

Hepatitis C outreach project and cross-sectional epidemiology in high-risk populations in Trondheim, Norway

BACKGROUND

Hepatitis C is highly prevalent among people who use drugs (PWUD), and the hepatitis C virus (HCV) epidemic is less characterised in Norway. The aims of the study were to assess the prevalence and treatment willingness in high-risk populations by reaching out to frequently visited sites for high-risk populations.

METHODS

Individuals from high-risk populations were included from September 2015 to March 2017. Two dedicated study nurses frequently visited the local opioid substitution clinic, outpatient clinics, PWUD day centres, local prison, and refugee centre in Trondheim, Norway. Demographic data, risk behaviour, and clinical symptoms were obtained by study questionnaire. Subjects with anti-HCV+ rapid test were subsequently tested for HCV RNA and genotyped. Viraemic patients were offered referral for HCV treatment evaluation.

RESULTS

A total of 381 participants were included in the study: 52 immigrants, 62 prisoners, and 267 PWUD. The anti-HCV prevalence rates were 0% (n = 0) in immigrants, 40% (n = 25) in prisoners, and 61% (n = 164) in PWUD, with 24% (n = 15) of prisoners and 42% (n = 108) of PWUD being viraemic. Of those qualifying for treatment (n = 31), 30 wished to be evaluated.

CONCLUSION

This study showed high HCV prevalence in prisoners and PWUD and that infected high-risk patients were interested in treatment evaluation.

T-Cell Immunity against the Hepatitis C Virus: A Persistent Research Priority in an Era of Highly Effective Therapy

Approximately 70% of acute hepatitis C virus (HCV) infections become chronic, indicating that the virus is exceptionally well adapted to persist in humans with otherwise normal immune function. Robust, lifelong replication of this small RNA virus does not require a generalized failure of immunity. HCV effectively subverts innate and adaptive host defenses while leaving immunity against other viruses intact. Here, the role of CD4⁺ and CD8⁺ T-cell responses in control of HCV infection and their failure to prevent virus persistence in most individuals are reviewed. Two issues of practical importance remain priorities in an era of highly effective antiviral therapy for chronic hepatitis C. First, the characteristics of successful T-cell responses that promote resolution of HCV infection are considered, as they will underpin development of vaccines that prevent HCV persistence. Second, defects in T-cell immunity that facilitate HCV persistence and whether they are reversed after antiviral cure to provide protection from reinfection are also addressed.

Screening for Sexually Transmitted Infections During Hepatitis C Treatment to Predict Reinfection Among People With HIV

Background

Little is known about the risk of hepatitis C virus (HCV) reinfection among people with HIV (PWH) in the direct-acting antiviral (DAA) era. We evaluate HCV reinfection rates in the DAA era and characterize presustained virologic response (SVR) behavioral risk factors associated with reinfection among PWH at the University of California, San Diego (UCSD).

Methods

Observational longitudinal cohort of PWH treated with DAAs between 2014 and July 2019 who achieved SVR and had at least 1 subsequent HCV viral load measurement. HCV reinfection was defined as new HCV viremia after SVR. We examined whether screening for sexually transmitted infections (STIs) and substance use during the pre-SVR period could identify patients at greater risk for reinfection using exact Poisson regression to compare reinfection incidence rates between those with and without pre-SVR STIs and positive urine drug screens.

Results

Eight out of 200 PWH were reinfected with HCV a median ~26 weeks after SVR over 328.1 person-years of follow-up (PYFU), for an incidence rate of 2.44/100 PYFU. The observed HCV reinfection rate was highest among men who have sex with men who inject drugs (MSM IDU; 4.63/100 PFYU) and those aged 30-39 years (6.80/100 PYFU). Having a positive gonorrhea/chlamydia test during the pre-SVR period was a predictor of HCV reinfection.

Conclusions

The HCV reinfection rate in the DAA era is similar to the rate observed in the interferon era in San Diego in PWH. STI screening during HCV treatment may help determine those at higher risk for HCV reinfection.

Hepatitis C Virus Treatment: Simplifying the Simple and Optimizing the Difficult

The availability of safe, efficacious, oral direct-acting antivirals (DAAs) have ushered in a new era of hepatitis C treatment with potential to eliminate hepatitis C as a public health threat. To achieve population-level effectiveness of these oral DAAs, hepatitis C treatment by a wide range of providers in different settings will be essential to increase the number of persons treated. We provide a clinical review of hepatitis C treatment with a focus on practical tools for management of hepatitis C in majority of currently infected individuals who can be easily cured and optimization of treatment for those in whom treatment may not be as simple.

Cost effectiveness of treatment models of care for hepatitis C: the South Australian state-wide experience

AIM

The objective was to study the long-term (lifetime) cost effectiveness of four different hepatitis C virus (HCV) treatment models of care (MOC) with directly acting antiviral drugs.

METHODS

A cohort Markov model-based probabilistic cost-effectiveness analysis (CEA) was undertaken extrapolating to up to 30 years from cost and outcome data collected from a primary study involving a real-life Australian cohort. In this study, noncirrhotic patients treated for HCV from 1 March 2016 to 28 February 2017 at four major public hospitals and liaising sites in South Australia were studied retrospectively. The MOC were classified depending on the person providing patient workup, treatment and monitoring into MOC1 (specialist), MOC2 (mixed specialist and hepatitis nurse), MOC3 (hepatitis nurse) and MOC4 (general practitioner, GP). Incremental costs were estimated from the Medicare perspective. Incremental outcomes were estimated based on the quality-adjusted life years (QALY) gained by achieving a sustained virological response. A cost-effectiveness threshold of Australian dollar 50 000 per QALY gained, the implicit criterion used for assessing the cost-effectiveness of new pharmaceuticals and medical services in Australia was assumed. Net monetary benefit (NMB) estimates based on this threshold were calculated.

RESULTS

A total of 1373 patients, 64% males, mean age 50 (SD ±11) years, were studied. In the CEA, MOC4 and MOC2 clearly dominated MOC1 over 30 years with lower costs and higher QALYs. Similarly, NMB was the highest in MOC4, followed by MOC2.

CONCLUSION

Decentralized care using GP and mixed consultant nurse models were cost-effective ways of promoting HCV treatment uptake in the setting of unrestricted access to new antivirals.

SARS-CoV-2 will constantly sweep its tracks: a vaccine containing CpG motifs in 'lasso' for the multi-faced virus

During the current COVID-19 pandemic, the global ratio between the dead and the survivors is approximately 1 to 10, which has put humanity on high alert and provided strong motivation for the intensive search for vaccines and drugs. It is already clear that if we follow the most likely scenario, which is similar to that used to create seasonal influenza vaccines, then we will need to develop improved vaccine formulas every year to control the spread of the new, highly mutable coronavirus SARS-CoV-2. In this article, using well-known RNA viruses (HIV, influenza viruses, HCV) as examples, we consider the main successes and failures in creating primarily highly effective vaccines. The experience accumulated dealing with the biology of zoonotic RNA viruses suggests that the fight against COVID-19 will be difficult and lengthy. The most effective vaccines against SARS-CoV-2 will be those able to form highly effective memory cells for both humoral (memory B cells) and cellular (cross-reactive antiviral memory T cells) immunity. Unfortunately, RNA viruses constantly sweep their tracks and perhaps one of the most promising solutions in the fight against the COVID-19 pandemic is the creation of 'universal' vaccines based on conservative SARS-CoV-2 genome sequences (antigen-presenting) and unmethylated CpG dinucleotides (adjuvant) in the composition of the phosphorothioate backbone of single-stranded DNA oligonucleotides (ODN), which can be effective for long periods of use. Here, we propose a SARS-CoV-2 vaccine based on a lasso-like phosphorothioate oligonucleotide construction containing CpG motifs and the antigen-presenting unique ACG-containing genome sequence of SARS-CoV-2. We found that CpG dinucleotides are the most rare dinucleotides in the genomes of SARS-CoV-2 and other known human coronaviruses, and hypothesized that their higher frequency could be responsible for the unwanted increased lethality to the host, causing a ‘cytokine storm’ in people who overexpress cytokines through the activation of specific Toll-like receptors in a manner similar to TLR9-CpG ODN interactions. Interestingly, the virus strains sequenced in China (Wuhan) in February 2020 contained on average one CpG dinucleotide more in their genome than the later strains from the USA (New York) sequenced in May 2020. Obviously, during the first steps of the microevolution of SARS-CoV-2 in the human population, natural selection tends to select viral genomes containing fewer CpG motifs that do not trigger a strong innate immune response, so the infected person has moderate symptoms and spreads SARS-CoV-2 more readily. However, in our opinion, unmethylated CpG dinucleotides are also capable of preparing the host immune system for the coronavirus infection and should be present in SARS-CoV-2 vaccines as strong adjuvants.

Hepatitis C Reinfection in People Who Inject Drugs in Resource-Limited Countries: A Systematic Review and Analysis

Hepatitis C (HCV) is a global pandemic. The World Health Organization has developed a strategic plan for HCV elimination that focuses on low- and middle-income countries (LMICs) and high-risk populations, including people who inject drugs (PWID). While direct-acting antiviral (DAA) therapies are highly effective at eliminating HCV infections and have few side effects, medical professionals and policymakers remain concerned about the risk of reinfection among PWID. This study is a systematic review of research measuring the rate of HCV reinfection among PWID in LMICs and identifies additional areas for further research. A systematic search strategy was used to identify studies documenting HCV reinfection after sustained virologic response in PWID in LMICs. We refined results to include studies where at least 50% of participants had DAA treatment for primary HCV infection. Pooled reinfection rate was calculated across all studies. Seven studies met eligibility criteria. Most studies were conducted in six upper middle-income countries (Mexico, Romania, Russia, Taiwan, Georgi, and Brazil) and one lower middle-income country (Bangladesh) with a total of 7665 participants. No study included information from PWID in low-income countries. Sample sizes ranged from 200 to 3004 individuals, with demographic data missing for most participants. Four studies used deep gene sequencing, and reflex genotyping procedures to differentiate reinfection (infection by a different HCV genotype/subtype) from virologic relapse (infection by the same strain). The follow-up time of people cured from primary chronic HCV infection ranged from 12 weeks to 6.6 years. The pooled reinfection rate of all seven studies was 2.8 (range: 0.02 to 10.5) cases per 100 person-years (PY). In the five studies that differentiated relapse from reinfection, the incidence of reinfection was 1.0 per 100 PY. To date, research on reinfection rates among PWID in LMICs remains limited. Research focused on PWID in low-income countries is particularly needed to inform clinical decision making and evidence-based programs. While rates of reinfection among PWID who complete DAA treatment in upper and lower middle-income countries were similar or lower than rates observed in PWID in high-income countries, the rates were highly variable and factors may influence the accuracy of these measurements. This systematic review identifies several areas for continued research. Policies concerning access to HCV testing and treatment should be comprehensive and not place restrictions on PWID in these settings.

IFNL3-adjuvanted HCV DNA vaccine reduces regulatory T cell frequency and increases virus-specific T cell responses

BACKGROUND & AIMS

Although direct-acting antiviral (DAA) treatment results in a sustained virologic response (SVR) in most patients with chronic HCV infection, they are at risk of re-infection. Moreover, the immune system is not completely normalized even after SVR (e.g. increased regulatory T [Treg] cell frequency). We developed a DNA vaccine, GLS-6150, to prevent re-infection of patients with DAA-induced SVR and evaluated its safety and immunogenicity in individuals with chronic HCV infection.

METHODS

GLS-6150 consists of plasmids encoding HCV non-structural proteins (NS3-NS5A) and adjuvant IFNL3. The vaccine was administered 4 times at 4-weekly intervals to 3 groups (1, 3, or 6 mg/vaccination; n = 6 per group), followed by a 6 mg boost at 24 weeks (n = 14). Peripheral blood T cell responses were evaluated by interferon (IFN)-γ enzyme-linked immunospot assays, intracellular cytokine staining, and major histocompatibility complex class-I (MHC-I) dextramer staining. Treg cell frequency was assessed by flow cytometry.

RESULTS

Severe adverse events or vaccine discontinuation were not reported. The IFN-γ spot-forming cells specific to NS3-NS5A were increased by GLS-6150. Both CD4+ and CD8+ T cells produced multiple cytokines. However, the frequency and phenotype of HCV-specific MHC-I dextramer+CD8+ T cells were not changed. Interestingly, the frequency of Treg cells, particularly activated Treg cells, was decreased by GLS-6150, as expected from previous reports that IFNL3 adjuvants decrease Treg cell frequency. Ex vivo IFN-λ3 treatment reduced Treg frequency in pre-vaccination peripheral blood mononuclear cells. Finally, Treg cell frequency inversely correlated with HCV-specific, IFN-γ-producing T cell responses in the study participants.

CONCLUSIONS

We demonstrate that GLS-6150 decreases Treg cell frequency and enhances HCV-specific T cell responses without significant side effects. A phase I clinical trial of GLS-6150 is currently underway in patients with DAA-induced SVR.

CLINICAL TRIAL NUMBER

NCT02027116.

LAY SUMMARY

Although direct-acting antivirals (DAAs) are successfully used for the treatment of chronic hepatitis C virus (HCV) infection, a prophylactic HCV vaccine needs to be developed, especially for patients who achieve a sustained virologic response. In the current study, we show that a DNA vaccine (GLS-6150) was safe and increased HCV-specific T cell responses. A clinical trial is underway to test this vaccine in patients with a sustained virologic response following DAA therapy.

Outcomes of Hepatitis C Virus Treatment in the New York City Jail Population: Successes and Challenges Facing Scale up of Care

BACKGROUND

The population detained in the New York City (NYC) jail system bears a high burden of hepatitis C virus (HCV) infection. Challenges to scaling up treatment include short and unpredictable lengths of stay. We report on the clinical outcomes of direct-acting antiviral (DAA) treatment delivered by NYC Health + Hospitals/Correctional Health Services in NYC jails from 2014 to 2017.

METHODS

We performed a retrospective observational cohort study of HCV patients with detectable HCV ribonucleic acid treated with DAA therapy while in NYC jails. Some patients initiated treatment in jail, whereas others initiated treatment in the community and were later incarcerated. Our primary outcome was sustained virologic response at 12 weeks (SVR12).

RESULTS

There were 269 patients included in our cohort, with 181 (67%) initiating treatment in jail and 88 (33%) continuing treatment started in the community. The SVR12 virologic outcome data were available for 195 (72%) individuals. Of these, 172 (88%) achieved SVR12. Patients who completed treatment in jail were more likely to achieve SVR12 relative to those who were released on treatment (adjusted risk ratio, 2.93; 95% confidence interval, 1.35-6.34). Of those who achieved SVR12, 114 (66%) had a subsequent viral load checked. We detected recurrent viremia in 18 (16%) of these individuals, which corresponded to 10.6 cases per 100 person-years of follow-up.

CONCLUSIONS

Hepatitis C virus treatment with DAA therapy is effective in a jail environment. Future work should address challenges related to discharging patients while they are on treatment, loss to follow-up, and a high incidence of probable reinfection.

Dissection of two drug-targeted regions of Hepatitis C virus subtype 4a infecting Egyptian patients

Recently, treatment of HCV infection has been improved after the development of direct acting antivirals (DAAs) which target different viral proteins (NS3-4A, NS5A and NS5B). The activity and effectiveness of these DAAs are affected by the presence of resistance associated substitutions (RASs). This study aimed to characterize HCV genotypes circulating among Egyptian HCV patients, to dissect the full sequences of HCV NS3-4A and NS5B regions, and to characterize RASs associated with NS3-4A and NS5B inhibitors in HCV treatment-naïve patients. Genotyping of 80 HCV samples from treatment-naïve patients was done using restriction fragment length polymorphism and phylogenetic analysis based on some full NS5B sequences. Results showed the prevalence of HCV subtype 4a. Twenty four new full sequences of NS3-4A and NS5B regions of subtype 4a were deposited in the GenBank database. In general, the substitutions associated with NS3-4A-targeting drugs were absent predicting possible responsiveness of Egyptian HCV patients to these drugs. In addition, the absence of amino acid substitutions associated with resistance to Sofosbuvir may predict good response to treatment with Sofosbuvir. Some amino acid substitutions associated with resistance to different classes of non-nucleoside inhibitors were detected. Further investigations on treated Egyptian HCV patients may evaluate the effectiveness of the massively used drugs. Many predicted T-cell-binding epitopes in NS3-4A and NS5B regions were found to be highly conserved in the currently studied isolates; a finding that might be important for HCV vaccine development. We demonstrated potential NS3 epitopes that could be used in engineering T cells against HCV epitopes.

Eradicating hepatitis C: Are novel screening strategies for people who inject drugs cost-effective?

BACKGROUND

In developed countries, people who inject drugs (PWID) have a high prevalence of hepatitis C virus (HCV), yet they are often under-diagnosed. The World Health Organization has set 2030 as a target year for HCV elimination. To meet this target, improving screening in convenient community settings in order to reach infected undiagnosed individuals is a priority. This study assesses the cost-effectiveness of alternative novel strategies for diagnosing HCV infection in PWID.

METHODS

A cost-effectiveness analysis was undertaken to compare HCV screening at needle exchange centres, substance misuse services and at community pharmacies, with the standard practice of detection during general practitioners' consultations. A decision tree model was developed to assess the incremental cost per positive diagnosis, and a Markov model explored the net monetary benefit (NMB) and the cost per Quality Adjusted Life Years (QALYs) gained over a lifetime horizon.

RESULTS

Needle exchange services provided a 7.45-fold increase in detecting positive individuals and an incremental cost of £12,336 per QALY gained against current practice (NMB £163,827), making this the most cost-effective strategy over a lifetime horizon. Screening at substance misuse services and pharmacies was cost-effective only at a £30,000/QALY threshold. With a 24% discount to HCV treatment list prices, all three screening strategies become cost-effective at £20,000/QALY.

CONCLUSIONS

Targeting PWID populations with screening at needle exchange services is a highly cost-effective strategy for reaching undiagnosed HCV patients. When applying realistic discounts to list prices of drug treatments, all three strategies were highly cost-effective from a UK NHS perspective. All of these strategies have the potential to make a cost-effective contribution to the eradication of HCV by 2030.

Co-Located hepatitis C virus infection treatment within an opioid treatment program promotes opioid agonist treatment retention

BACKGROUND

Co-located treatment for hepatitis C virus (HCV) infection for patients with opioid use disorder (OUD) within an opioid treatment program (OTP) addresses gaps in the HCV care continuum. Few reports have analyzed outcomes related to OUD treatment, such as retention, associated with co-located HCV treatment.

METHODS

Patients (n = 89) treated for OUD and chronic HCV infection in a Northeast US OTP from January 2014 through July 2017 were compared to control patients (n = 199) being treated for OUD and diagnosed with but not treated for HCV during the same period. All patients received opioid agonist treatment (OAT). The outcome of interest is patient retention in the OTP from January 2014 through September 2018, analyzed using logistic regression and survival analysis based on OTP loss to follow-up dates.

RESULTS

After adjusting for baseline covariates, patients who completed HCV treatment had 2.22 (95 % CI: 1.11, 4.45) increased likelihood of remaining in the OTP compared to patients in the control group. Survival analysis indicated the HCV treatment group had a significantly greater probability of being retained over the duration of the study compared with the control group.

CONCLUSION

Results indicate that a co-located model of care is associated with improved OTP treatment retention following HCV treatment, and suggest that co-locating HCV and OUD treatment has a secondary impact on keeping patients engaged in OAT.

Low Hepatitis C Reinfection Following Direct-acting Antiviral Therapy Among People Who Inject Drugs on Opioid Agonist Therapy

BACKGROUND

Direct-acting antiviral (DAA) therapy is highly effective in people who inject drugs (PWID); however, rates, specific injection behaviors, and social determinants associated with hepatitis C virus (HCV) reinfection following DAA therapy among PWID on opioid agonist therapy (OAT) are poorly understood.

METHODS

PREVAIL was a randomized controlled trial that assessed models of HCV care for 150 PWID on OAT. Those who achieved sustained virologic response (SVR) (n = 141; 94%) were eligible for this extension study. Interviews and assessments of recurrent HCV viremia occurred at 6-month intervals for up to 24 months following PREVAIL. We used survival analysis to analyze variables associated with time to reinfection.

RESULTS

Of 141 who achieved SVR, 114 had a least 1 visit in the extension study (62% male; mean age, 52 years). Injection drug use (IDU) was reported by 19% (n = 22) in the extension study. HCV reinfection was observed in 3 participants. Over 246 person-years of follow-up, the incidence of reinfection was 1.22/100 person-years (95% CI, 0.25-3.57). All reinfections occurred among participants reporting ongoing IDU. The incidence of reinfection in participants reporting ongoing IDU (41 person-years of follow-up) was 7.4/100 person-years (95% CI, 1.5-21.6). Reinfection was associated with reporting ongoing IDU in the follow-up period (P < .001), a lack confidence in the ability to avoid contracting HCV (P < .001), homelessness (P = .002), and living with a PWID (P = .007).

CONCLUSIONS

HCV reinfection was low overall, but more common among people with ongoing IDU following DAA therapy on OAT, as well as those who were not confident in the ability to avoid contracting HCV, homeless, or living with a PWID. Interventions to mediate these risk factors following HCV therapy are warranted.