Every year viral hepatitis causes almost one and a half million deaths worldwide, more than HIV, tuberculosis, or malaria. Hepatitis B virus (HBV) and hepatitis C virus (HCV) account for 96 percent of these deaths, more than 20,000 a year in the United States alone. Such loss of life comes at a cost to society, both directly, through the expense of treatment, and indirectly, through the loss of adults in their prime; viral hepatitis culls most heavily from the 45 to 64 age group. It is therefore surprising how relatively little public or scientific attention viral hepatitis has garnered. In a 2016 report the World Health Organization (WHO) described it as “largely ignored as a health and development priority until recently.”2
But because of recent advances, hepatitis C is now curable with short and easily tolerable courses of treatment; treatment can prevent most deaths from hepatitis B, and there is an effective vaccine against hepatitis B. Such developments inspired the World Health Assembly resolution in June 2016 to eliminate viral hepatitis as a major public health problem by 2030.
1 References are not included in the summary; please see the body of the report for references and the bulk of the discussion and justification.
3 The committee’s phase one report, Eliminating the public health problem of hepatitis B and C in the United States: Phase one report, is available for free download. Please see Chapter 1 for the full statement of task.
4 The Centers for Disease Control and Prevention’s (CDC’s) Office of Viral Hepatitis and the Department of Health and Human Services’ Office of Minority Health sponsored the first
consider the feasibility of such a goal in the United States. The committee’s previous report concluded that hepatitis B and C could be eliminated as a public health problem, defining a public health problem as a disease that by virtue of morbidity, mortality, or transmission commands attention as a major threat to health in a community. In this report, the second of two, the committee lays out appropriate goals for disease reduction and a path to achieve these goals. The report is organized according to the WHO strategy document, which encourages countries to consider five areas (information, interventions, service delivery, financing, and research) in forming their national plans. Each report chapter deals with one of these topics; a separate chapter presents results of commissioned models informing the committee’s conclusions on a suitable timeline and targets.
TARGETS FOR ELIMINATION
As a first step to identifying targets for eliminating hepatitis B and C from the United States, the committee commissioned models to estimate the effects of different interventions on disease burden. Modelers were chosen for their prior work in the field; only models that have been extensively validated and peer reviewed were considered. Given the differences in biology, epidemiology, and treatment options for hepatitis B and C, the models presented are not directly comparable, but both consider the reduction in morbidity and mortality that might be expected from different strategies for diagnosis, care, and treatment.
Hepatitis B Models
The hepatitis B model compared different levels of diagnosis, care, and treatment on the population of HBV-infected people in the United States. The modeled prevalence of chronic hepatitis B was 1.29 million cases (range: 855,000 to 2.02 million cases). It found that diagnosing two-thirds of hepatitis B cases in the United States, almost doubling the current diagnosis rate, but changing nothing else, would reduce deaths by only 4.5 percent by 2030. In order to see a meaningful reduction in deaths, simultaneous improvements would have to be made in care and treatment of chronic infection. Diagnosing 90 percent of cases, bringing 90 percent of those to care, and treating 80 percent of those for whom treatment is indicated, on the other hand, would, assuming highly motivated patients with good adherence to treatment, result in a cumulative 50 percent reduc-
phase of this report. They were joined in phase two by the American Association for the Study of Liver Diseases, the CDC Division of Cancer Prevention and Control, the Infectious Diseases Society of America, and the National Viral Hepatitis Roundtable.
tion in deaths by 2030 (relative to a 2015 baseline), averting over 60,000 deaths. The same level of diagnosis, care, and treatment would reduce incident cirrhosis by about 45 percent and new cases of hepatocellular carcinoma by a third.
The model has important limitations. The model cohort does not include the roughly 23,370 new cases of chronic hepatitis B that enter the United States every year from immigration (about 1 percent of the total cases) or the relatively small number of chronic infections acquired domestically.5 When considering these cases, the prevalence of chronic hepatitis B will increase from 1.29 million in 2015 to 1.64 million in 2030. These additional cases would not, however, affect the estimated percent reduction in cumulative risk if they follow the same diagnosis, care, and treatment patterns.
The model also does not include strategies to end mother-to-child transmission of HBV or chronic hepatitis B as a result of horizontal transmission, partly because both are rare in the United States. However, work in Alaska has shown that it is possible to fully eliminate both.
Hepatitis C Models
The hepatitis C model compared four scenarios of diagnosis and treatment coverage on incidence and prevalence of hepatitis C and on liver-related deaths, liver cancer, and cirrhosis. It suggested considerable public health benefit to combining aggressive case finding with unrestricted treatment for chronic hepatitis C. In such a scenario, the total number of viremic cases would drop 85 percent and annual deaths from chronic HCV infection would drop 65 percent by 2030 (relative to 2015), averting a cumulative 28,800 deaths between 2015 and 2030. The same level of treatment and case finding would reduce incident infections by 90 percent (relative to 2015) by 2030.
The model’s limitations include the assumption that only 260,000 people can be treated in a year. There is no reason why this number could not increase, especially if the capacity of primary care providers to treat hepatitis C were expanded. The model also assumes diagnosis of 110,000 new cases a year until 2020 and roughly 70,000 to 90,000 a year between 2020 and 2030. Case finding will be more challenging as time passes; the people in contact with the health system will have already been cured. Meeting the target of a two-thirds reduction in HCV-related deaths by 2030 will require special attention to testing and treatment among people who inject drugs, a population accounting for most new HCV infections in the United States, and people in prisons.
5 Fewer than 2,000 a year from vertical and horizontal transmission combined.
A Central Coordinating Office
The targets presented in this report represent the committee’s best effort to balance a compelling public health target against practical constraints. Meeting these targets depends on considerable improvements in testing, diagnosis, and care, as well as increased preventive measures and focused research. The actions recommended in this report all advance some part of the larger goal: eliminating the public health problem of hepatitis B and C in the United States by 2030. This program will require the cooperation of various federal and state government agencies, as well as professional societies, legislators, and private companies. With work spread among so many organizations, the opportunity for distraction is real. The leadership of a single office would help ensure efficient and harmonious work.
Recommendation 2-1: The highest level of the federal government should oversee a coordinated effort to manage viral hepatitis elimination.
Strong central leadership is a characteristic of successful disease elimination programs. The elimination strategy described in this report may have particular need for such leadership, given its emphasis on reaching people who inject drugs and novel strategies to finance medicines for Medicaid beneficiaries and prisoners.
PUBLIC HEALTH INFORMATION
Chronic hepatitis B and C are both clinically silent in most patients. Serious symptoms may not emerge for decades, and the root infection is often unrecorded on death certificates. This long latency is part of the reason why morbidity and mortality from viral hepatitis are undercounted. A better understanding of the true burden of disease will be essential when tracking progress toward elimination. Measuring disease burden is the primary responsibility of state and local health departments, but is something most health departments are not in a position to do.
Describing the Viral Hepatitis Epidemic
The Centers for Disease Control and Prevention (CDC) currently supports enhanced viral hepatitis surveillance in seven jurisdictions, and these offices are finding considerably higher disease burden than national data would suggest. Proper viral hepatitis surveillance requires tracking patients over time and processing a large amount of data for every case. The data gleaned from routine surveillance can identify spikes in new infections, give insight into patterns of access to care, help estimate disease prevalence in
an area, and tailor prevention and response programs. Highly automated surveillance systems can help make this task more efficient; an investment in such systems and the human expertise to manage them would advance the goal of hepatitis elimination in the United States.
Recommendation 3-1: The Centers for Disease Control and Prevention (CDC), in partnership with state and local health departments, should support standard hepatitis case finding measures and the follow-up, monitoring, and linkage to care of all viral hepatitis cases reported through public health surveillance. The CDC should work with the National Cancer Institute to attach viral etiology to reports of liver cancer in its periodic national reports on cancer.
The use of automated, electronic reporting from diagnostic laboratories holds promise to improve viral hepatitis case finding. Such systems cannot replace traditional surveillance, however. The work of managing data, tracking cases, and describing the demographics and risk factors for viral hepatitis will continue to fall on health department epidemiologists. Their work might be made easier by changes to state regulations on the reporting of HBV and HCV test results. A negative HCV RNA test result after treatment is particularly valuable as it indicates sustained virologic response or cure of hepatitis C, but such results are not reportable in many states.
Measuring mortality due to viral hepatitis could be improved by attention to cancer registries. A classification system that captures liver cancer etiology would improve understanding of the burden of HBV infection and HCV infection.
A better understanding of the incidence of viral hepatitis would come from cohort studies, especially among high-risk populations. Further, periodic cross-sectional surveys in similar populations would inform a more accurate understanding of disease prevalence and trends therein. Such studies would complement information about hepatitis coming from population-based surveys.
Recommendation 3-2: The Centers for Disease Control and Prevention should support cross-sectional and cohort studies to measure HBV and HCV infection incidence and prevalence in high-risk populations.
The CDC could make use of existing contacts for sero-surveys in populations at risk for hepatitis. Serum analysis is clearly essential in any study of viral hepatitis, and researchers should be encouraged to measure a basic panel of serum biomarkers including HBsAg, total anti-HBc, and anti-HBs, HCV RNA, and HCV antibody. The new HCV immunoglobulin antibody avidity assay, which measures biomarkers that change with duration of in-
fection, could be used with HCV RNA to identify new infections. Though validation studies are ongoing, this assay promises to improve estimates of incidence of hepatitis C, especially in high-risk groups.
This committee’s first report reviewed the epidemiology of hepatitis B and C in the United States. With this review in mind, the committee considered specific actions with the power to interrupt transmission of HBV and HCV and prevent morbidity and mortality from chronic infection. In identifying interventions with the greatest possible effect, the committee considered a continuum of services from prevention to chronic care. As much as possible, this report separates discussion of essential interventions from strategies for improving their delivery.
Prevention and Testing
Prevention is the first step to eliminating the public health problem of hepatitis B and C.
Prevention of HBV Infection
Immunization against HBV can prevent 95 percent of infections. About 90 percent of U.S. children were fully immunized against HBV in 2013, but as of 2014, only about a quarter of adults over 19 were. Unvaccinated adults remain vulnerable to HBV infection through unprotected sex or contact with infected blood. There is not good awareness of the importance of adult vaccination however, and clinics often fail to stock the vaccine, partly because there is no funding to deliver it to uninsured and underinsured adults, and partly because they fear losing patients over the three-dose vaccine schedule.
Adult immunization does not have to be so complicated. Every year since 2009 about 40 percent of adults in the United States have received seasonal influenza vaccine. If states supported hepatitis B vaccination to the same level as seasonal influenza vaccine, great improvements could be made in hepatitis B immunization. The relative success of seasonal influenza immunization is partly a matter of making vaccination convenient, especially for hard-to-reach patients, including homeless people and substance users. Offering vaccination in pharmacies is one way to reach a wider cross-section of the population, as pharmacies have evening and weekend hours without appointment. Some states restrict the types of vaccines offered in pharmacies and the circumstances under which pharmacists may
administer them, however. State laws reimbursing pharmacies for vaccines also vary widely.
Recommendation 4-1: States should expand access to adult hepatitis B vaccination, removing barriers to free immunization in pharmacies and other easily accessible settings.
Early vaccination and dosing with hepatitis B immune globulin can prevent mother-to-child transmission of HBV even among HBeAg+ women. Infants born to highly viremic women face particular risks, however. About 9 percent of infants born to women with HBV DNA greater than 20 million IU/mL contract HBV at birth despite proper prophylaxis.
Among highly viremic women, prophylactic antiviral therapy in the third trimester of pregnancy has been shown to further reduce perinatal HBV transmission. At the same time, women may experience hepatitis flare after stopping treatment, making long-term antiviral therapy necessary. The precise viral load threshold for antiviral therapy is not clear, but all HBsAg+ pregnant women should have early testing so that they and their doctors can weigh the pros and cons of antiviral prophylaxis.
Recommendation 4-2: The Centers for Disease Control and Prevention, the American Association for the Study of Liver Diseases, the Infectious Diseases Society of America, and the American College of Obstetricians and Gynecologists should recommend that all HBsAg+ pregnant women have early prenatal HBV DNA and liver enzyme tests to evaluate whether antiviral therapy is indicated for prophylaxis to eliminate mother-to-child transmission or for treatment of chronic active hepatitis.
Prevention of HBV and HCV Infections
There is no vaccine for HCV and, until there is, prevention will be mostly a matter of limiting exposure to the virus. One component of prevention is curing all chronic infections, thereby removing infected cases from the population. Stopping transmission also depends on reducing risk of HCV among people who inject drugs, a group that accounts for 75 percent of the roughly 30,500 new HCV infections every year in the United States.
Stopping HCV transmission among people who inject drugs is challenging. HCV can survive on fomites for hours, even days, and transmission by needle stick is 10 times more efficient for HCV than HIV. The best way to prevent hepatitis C in this population is to combine strategies that improve the safety of injection with those that treat the underlying addiction.
Opioid agonist therapy can relieve the symptoms of drug withdrawal and is considered part of the tertiary prevention of substance use disorder (meaning that it prevents the worst complications of the condition). However, 30 million Americans live in places where not a single provider can prescribe opioid agonists. Syringe exchange programs, similarly, do not have sufficient coverage even in cities. Rural and suburban areas, home to half of people who inject drugs, have 30 percent of the nation’s syringe services and distribute only 8 percent of the total number of syringes.
Recommendation 4-3: States and federal agencies should expand access to syringe exchange and opioid agonist therapy in accessible venues.
Evidence indicates that syringe exchange programs neither encourage new users nor increase drug use among clients. Nevertheless, in some states, drug paraphernalia laws and regulations on the sale of syringes can impede the proper reach of syringe services. Expanding syringe exchange to rural and suburban areas may require modification to models developed in cities. Pharmacies may be a promising venue for syringe exchange, as they are accessible to people in most parts of the country and reasonably well equipped to provide a confidential space for counseling. Exchanges operating from a van or bus can reach more people and face less community opposition than a fixed-site exchange. They may also be more appealing to younger clients and to people concerned with maintaining anonymity.
Diagnosis of infected cases is also essential for elimination. U.S. Preventive Services Task Force guidelines recommend screening for people at high risk of HBV or HCV infection, but wider screening may be warranted. Compliance with the current recommendation that anyone born between 1945 and 1965 be screened for HCV is poor.
Emergency departments serve as safety net providers for uninsured and underinsured people, and some have explored opt-out screening for hepatitis C. As the elimination effort continues, finding cases in emergency departments and other such settings will be a key to continued progress.
Recommendation 4-4: The Centers for Disease Control and Prevention should work with states to identify settings appropriate for enhanced viral hepatitis testing based on expected prevalence.
Care and Treatment
The direct-acting antivirals that cure hepatitis C make elimination feasible in the United States. There is no comparable cure for hepatitis B, but entecavir and tenofovir are effective at viral suppression and are cost-effective.
The combination of cost and demand for hepatitis C treatments has
strained the budgets of many payers since these drugs came to market. Insurers responded with restrictions that create more work for providers. There is also evidence of disparities in access to treatment. A recent study found that 46.3 percent of Medicaid patients were refused treatment, compared to only 5.0 percent of Medicare patients and 10.2 percent of patients with commercial insurance.
Delaying treatment only increases a patient’s risk of cirrhosis, liver cancer, and death. There are also consequences to society, as failure to treat chronic HCV infection creates a reservoir for transmission. Treating everyone with chronic hepatitis C, regardless of disease stage, would avert considerable suffering and anxiety.
Recommendation 4-5: Public and private health plans should remove restrictions that are not medically indicated and offer direct-acting antivirals to all chronic hepatitis C patients.
Without universal hepatitis C treatment, elimination of viral hepatitis will not be possible in the United States. Health plans should not stand in the way of this goal. The committee recognizes that the cost of the drugs presents an obstacle to universal treatment, but a strategy to control these costs is discussed later.
Part of the challenge of eliminating hepatitis B and C in the United States is that the people suffering from or at risk for the infections are often not engaged in care. Therefore, the elimination strategy must give as much attention to the delivery of services as to the services themselves. This piece of the strategy considers steps that could be taken to make viral hepatitis a higher priority, to support efficient care, and to reach patients who might otherwise be neglected.
There is often a gap between the practice of medicine as recommended by experts and what actually happens. Closing this gap is of concern to the National Committee for Quality Assurance (NCQA) which maintains the HEDIS6 indicators, a set of measures used to monitor the performance of 90 percent of American health plans. HEDIS measures command a certain attention from providers and health plan managers. Addition of viral hepatitis indicators to HEDIS would help make these services higher priority.
6 Officially, the Healthcare Effectiveness Data and Information Set.
Recommendation 5-1: The National Committee for Quality Assurance should establish measures to monitor compliance with viral hepatitis screening guidelines and hepatitis B vaccine birth dose coverage and include the new measures in the Healthcare Effectiveness Data and Information Set.
Screening and immunization measures would benefit from NCQA’s attention, and they meet established criteria for inclusion in HEDIS. Increased screening could also encourage improvements to point of care assays for HBsAg and HCV core antigen.
Various measures of child and adolescent immunization are also included in HEDIS, including full immunization against HBV in the first year of life. This indicator does not take into account the relative importance of the timing of the first dose, however. Children born to HBsAg+ women or to women who have not been tested for HBV infection require vaccination within 12 hours of birth, others within 1 day of birth. Emphasis on the hepatitis B birth dose as well as the completion of the series could help direct attention to this essential intervention.
Primary care is an efficient way to provide services, and viral hepatitis services should be no exception. At the same time, treating viral hepatitis carries risks that providers in small practices may be reluctant to accept, causing a disparity where viral hepatitis care is out of reach for people in rural and underserved communities.
There is precedent for managing hepatitis C in primary care. The University of New Mexico’s ECHO7 program is one example of an ongoing training and support program between primary providers and specialists. ECHO and similar programs have transferable lessons for building capacity in primary care and could be replicated at large scale with support from professional societies.
Recommendation 5-2: The American Association for the Study of Liver Diseases and the Infectious Diseases Society of America should partner with primary care providers and their professional organizations to build capacity to treat hepatitis B and C in primary care. The program should set up referral systems for medically complex patients.
Capacity building in primary care will have to go beyond one-time training programs and include standing teleconferences to keep the lines
7 Officially, Extension for Community Healthcare Outcomes.
of communication between primary care providers and specialists open. A shared patient information system accessible to all involved providers will also be important to track patients over time and facilitate shared decision making.
Eliminating viral hepatitis will also require additional work to reach patients who are not in regular contact with any primary care provider. Some of the people with the most serious need for viral hepatitis care are hard to reach: people born abroad, who are uninsured, who have substance use problems, and who are or have been imprisoned. Various federal and state agencies should give more explicit attention to bringing hepatitis services to these populations. The Ryan White Act8 was passed in response to a similar problem with HIV. A system of the same breadth and flexibility would go far to reaching marginalized viral hepatitis patients. While building a parallel program comparable to Ryan White might not be feasible, outreach activities for viral hepatitis could be built onto existing Ryan White programs, using separate funding for HIV-negative people.
Recommendation 5-3: The Department of Health and Human Services should work with states to build a comprehensive system of care and support for special populations with hepatitis B and C on the scale of the Ryan White system.
People in jails and prisons bear a particularly high burden of viral hepatitis; CDC estimates from the early 2000s put the prevalence of hepatitis C in correctional facilities at 12 to 35 percent and chronic hepatitis B infection between 1 and 3.7 percent. Unprotected sex and needle sharing are both common among incarcerated people, making jails and prisons an amplifying reservoir for the infections. Ironically, correctional facilities are also an ideal place to test and vaccinate for HBV and to cure chronic HCV infection, as directly observed therapy is the norm and the risk of drug diversion is low.
Recommendation 5-4: The criminal justice system should screen, vaccinate, and treat hepatitis B and C in correctional facilities according to national clinical practice guidelines.
Prisons and jails have a constant rotation of inmates, sometimes living in close quarters. The mixing of people and opportunities for disease transmission make immunization important. Nevertheless, the cost of vaccines and problems with staffing make it difficult for states to vaccinate widely in jails and prisons. More attention to testing for HBV infection could help
8 Officially, the Ryan White Comprehensive AIDS Resources Emergency Act of 1990.
draw attention to the related problem of immunization. If many inmates are shown to be vulnerable to HBV infection, correctional health officers might be able to make a stronger case to their state authorities for immunization support.
Screening inmates for viral hepatitis will bring many new diagnoses to light, especially cases of chronic hepatitis C. Concerns about the adequacy of treating these cases may have prevented prison health officers from screening more aggressively. The expense of testing, vaccination, and treatment is a barrier to hepatitis care in jails and prisons. Strategies to defray these expenses are discussed in the next section.
Eliminating the public health problem of hepatitis B and C will require increasing preventive and therapeutic services. There will be an expense to this increase, but the cost of inaction is also high. By a 2009 estimate, Medicare alone stood to absorb a fivefold increase in hepatitis C expenses, and the introduction of direct-acting antivirals has only increased this estimate. U.S. payers will spend an estimated $136 billion on hepatitis C drugs between 2015 and 2020, about 45 percent of which will come from the government.
In 2016 Congress allocated over a billion dollars to treat hepatitis C in veterans. The committee commends this decision and sees complementary spending on prevention and treatment for a wider patient group as the best strategy to protect the taxpayers’ investment. Congress is in the best position to marshal funds to implement the strategy outlined in this report.
A discretionary program would be one way for Congress to track the effects of their spending over time. As discussed in the previous section, it might be most efficient to use another discretionary program, the Ryan White Act, to reach viral hepatitis patients with overlapping risk factors for HIV. Any modifications to the Ryan White Act should make it clear that services for viral hepatitis patients should supplement the program’s main goal of supporting treatment for poor and uninsured HIV patients. It is also important to remember that the Ryan White Act was passed out of concern for marginalized people facing a lifetime of expensive medical care. Loosening its restrictions to cover viral hepatitis treatments would be consistent with the spirit of this law and would hasten the end of a disease that poses particular risk to people with HIV.
A Purchasing Strategy for Medicines
The cost of the direct-acting antivirals that cure HCV infection is a major obstacle to elimination. These drugs have strained the budgets of
public and private payers alike. Faced with the unenviable task of allocating scarce treatment, payers gave first priority to the sickest patients, those at most immediate risk of death. Many also imposed sobriety restrictions, fearing the risk of reinfection in active drug users too great to justify the expense of treatment. Such restrictions have met with criticism. Overt drug rationing offends the American public, but it is difficult to know how else to act in the face of such high prices.
Unrestricted mass treatment of hepatitis C will be necessary to eliminate the disease as a public health problem by 2030, but no direct-acting agent will come off patent before 2029. Delaying mass treatment would result in tens of thousands of needless deaths and billions of dollars in wasted medical costs. It is the government’s role to avoid such suffering, while still respecting innovator drug companies’ right to compensation for the risk they took to bring a valuable product to market.
Recommendation 6-1: The federal government, on behalf of the Department of Health and Human Services, should purchase the rights to a direct-acting antiviral for use in neglected market segments, such as Medicaid, the Indian Health Service, and prisons. This could be done through the licensing or assigning of a patent in a voluntary transaction with an innovator pharmaceutical company.
There are times when the government must act to correct a market failure. With this in mind, the committee recommends a voluntary transaction between the government and the companies producing direct-acting antivirals wherein the companies compete to sell their patent rights to the federal government for use in neglected populations. The voluntary nature of this process guarantees the drug company reasonable compensation; the patent holder has the option to walk away if the price is too low. Furthermore, the government would license the patent only for use in those populations for whom the government buys and access is limited, such as prisoners and Medicaid beneficiaries. This limitation will also control costs; the government should not have to pay as much as if it were compromising the lucrative private market.
Calculations shown in Chapter 6 suggest that the licensing rights should cost about $2 billion, after which states would pay about $140 million to treat 700,000 Medicaid beneficiaries and prisoners. For comparison, under the status quo it would cost about $10 billion over the next 12 years to treat only 240,000 Medicaid beneficiaries and prisoners.
Critics of this strategy may maintain that it sets a dangerous precedent; they may fear the government negotiating a license for other expensive medicines. This is unlikely, as the U.S. government has never been inclined to such action. In general, the United States is extremely supportive of the
pharmaceutical industry, investing heavily in the science infrastructure that supports it and paying more for medicines than other rich countries. Indeed, the government’s very reluctance to interfere in the pharmaceutical market may have emboldened the industry. The Senate Finance Committee’s investigation into the pricing of sofosbuvir concluded that Gilead9 had deliberately elevated the price in an effort to raise the market floor, ensuring continued high prices for all future hepatitis C treatments. Action now might discourage other companies from pursuing this strategy in the future.
The WHO identified research as one of the essential pieces of any country’s viral hepatitis elimination strategy. For the United States, a comparative advantage in science and technology compels special attention to research. Yet despite being the seventh leading cause of death in the world, viral hepatitis accounts for less than 1 percent of the National Institutes of Health’s research budget.
This report identified a series of key gaps in the research that would benefit from scientific attention, broadly divided into mechanistic and implementation research questions. Mechanistic research questions include the immune response and curative therapies for HBV and vaccine for HCV, as well as rapid diagnostic tests and new treatments for fibrosis, cirrhosis, and liver cancer. Implementation research questions include how to manage substance use in prisons and ways to reach key populations, as well as novel strategies for harm reduction, better understanding of networks of drug users, and prevention of injection drug use.
9 The innovator pharmaceutical firm that brought the drug to market.