Short-Course Antiviral Therapy Cures Acute Hepatitis C, But Eight Weeks May Be the Floor

A new systematic review and meta-analysis published in Virology Journal has brought together the scattered clinical evidence on treating acute hepatitis C virus (HCV) infection with interferon-free, dual direct-acting antiviral (DAA) regimens, and the headline finding is striking: across fourteen studies encompassing 1,078 treated patients, the pooled rate of sustained virological response at twelve weeks after therapy (SVR12) — the standard benchmark for cure — reached 97.7 percent. The analysis, conducted by Nada Mansour and Ahmed M. Kamel of Cairo University’s Faculty of Pharmacy together with Ramy M. F. Elbarody of King Salman Specialist Hospital in Saudi Arabia, also delivers a nuanced message about treatment duration. Cure rates climbed steadily as courses lengthened, from under 85 percent at four weeks to above 99 percent at eight weeks, suggesting that while ultra-short therapy remains tempting, eight weeks may represent the practical minimum for reliably eradicating recently acquired infection.

Acute HCV infection occupies a distinctive position in viral hepatitis control. Unlike chronic infection, which develops silently over years, acute infection is by definition a recent event, often detectable within weeks to months of transmission. It does not spread randomly through populations: it clusters disproportionately among men who have sex with men living with HIV, where sexual networks and immune compromise combine to fuel outbreaks, and among people who inject drugs, where sharing of injection equipment sustains chains of transmission. This clustering is precisely what makes early treatment so valuable from a public health standpoint. Curing an individual during the acute phase not only prevents progression to chronic liver disease but also removes that person from the pool of infectious individuals, interrupting onward transmission at a moment when the virus has had little time to disseminate through a network.

The therapeutic landscape that made such early intervention conceivable is the DAA revolution. Direct-acting antivirals target specific viral proteins — the NS3/4A protease, the NS5A protein, and the NS5B polymerase — and, when combined in dual or triple regimens, can block viral replication at multiple independent points. The older interferon-based therapies, with their punishing side-effect profiles and months-long courses, have been almost entirely displaced. Yet a genuine uncertainty persisted in the acute setting: chronic HCV is routinely cured with eight to twelve weeks of dual or triple DAA therapy, but acute infection presents a different virological and immunological context, and the question of whether shorter courses might suffice — four weeks, perhaps six — remained unresolved. The new analysis was designed to answer exactly that question, and to determine whether the choice of regimen mattered as much as the length of treatment.

Methodologically, the review was rigorous and prospectively registered. The authors searched MEDLINE, Scopus, and the Cochrane Central Register of Controlled Trials through 1 July 2026 for studies of interferon-free dual-DAA therapy in acute or recently acquired HCV that reported SVR12. The protocol was prepared a priori and lodged with PROSPERO, the international prospective register of systematic reviews, under registration number CRD420261464486. Because most of the available evidence consists of uncontrolled case series rather than randomised trials, the authors appraised each study as a single-arm case series and pooled the cure proportions using random-intercept logistic regression, a technique that models between-study heterogeneity more appropriately for proportions than simple pooling of rates. Fourteen studies yielded nineteen single-arm analysis units covering 1,078 patients, and the pre-specified subgroups were regimen, treatment duration, study design, and HIV status.

The pooled result of 97.7 percent, with a 95 percent confidence interval of 94.7 to 99.1 percent, is remarkable for its consistency: the I² statistic, a standard measure of heterogeneity, stood at just 30.4 percent, indicating that the studies were largely telling the same story despite differences in populations, regimens, and settings. In absolute terms, 1,043 of the 1,078 treated patients achieved SVR12. For a disease that, in the interferon era, was cured in well under half of acutely treated patients even after six months of therapy, this figure encapsulates how completely the pharmacology of HCV has been transformed. Equally notable is what did not predict cure: the pooled SVR12 did not differ significantly by regimen (p = 0.608), by study design (p = 0.764), or by HIV status (p = 0.975). Co-infection with HIV, long a complicating factor in hepatitis C management, did not appear to blunt the efficacy of dual-DAA therapy in the acute setting.

Duration, however, was a different matter entirely, and the gradient the authors observed is the analytical heart of the paper. At four weeks of therapy, pooled SVR12 was 84.8 percent (95 percent CI 74.1 to 91.6). At six weeks it rose to 91.7 percent (86.2 to 95.1). At eight weeks it reached 99.4 percent (97.5 to 99.9), and at twelve weeks it was 97.4 percent (91.7 to 99.2). The between-subgroup difference was highly significant, with p less than 0.001. The pattern suggests a pharmacological logic: viral load in acute infection can be extraordinarily high, and the probability that a fixed duration of dual therapy eliminates every last replicating virion depends on how much time the drugs have to drive viral populations to extinction. Below roughly eight weeks, the margin of safety narrows visibly; at eight weeks and beyond, cure approaches the ceiling that assay sensitivity allows.

The authors were careful to test the robustness of their pooled estimate, and the result survived every challenge they threw at it. Sensitivity analyses restricted to randomised trials alone, excluded the study judged to be at highest risk of bias, and systematically removed one study at a time in leave-one-out analyses; in each case the pooled SVR12 remained stable. This kind of stress-testing matters because meta-analyses of single-arm studies are vulnerable to small-study effects and to the idiosyncrasies of individual cohorts. The fact that the estimate barely moved under these perturbations lends considerable weight to the central conclusion that dual-DAA therapy in acute HCV performs at or near the levels achieved in chronic infection.

Yet the authors stop well short of declaring the question settled, and their caution is warranted on two grounds. First, the evidence base remains predominantly single-arm: without concurrent control groups, one cannot fully exclude that some acute infections would have resolved or responded differently under other conditions, and the pooled estimate reflects observational experience rather than randomised comparison. Second, and more subtly, regimen and duration are partially confounded in the available literature — certain regimens were used predominantly in short-course studies, so the apparent irrelevance of regimen (p = 0.608) may partly reflect that entanglement rather than a true pharmacological equivalence. The authors explicitly call for randomised duration-comparison trials to confirm the optimal short-course strategy before clinical practice abandons conventional durations.

The practical implications nonetheless point in a clear direction. The findings support early treatment of acute HCV — treating promptly upon diagnosis rather than waiting to see whether spontaneous clearance occurs — and they favour a course of at least eight weeks. For the populations in which acute infection clusters, this matters concretely. In HIV care settings, where patients are monitored frequently and incident infections can be detected early, an eight-week dual-DAA course offers near-certain cure with minimal pill burden. Among people who inject drugs, where retention in care is the dominant challenge, every week of treatment removed from a regimen increases the likelihood of completion; but the data here suggest that shaving duration below eight weeks trades a real loss in cure probability for that convenience, a trade-off that 85 percent cure at four weeks does not obviously justify when 99 percent is achievable with four more weeks of therapy.

Placed in the broader context of global HCV elimination goals, the study adds a piece to a puzzle that extends well beyond acute infection. The World Health Organization has set targets for eliminating viral hepatitis as a public health threat, and mathematical models have repeatedly shown that treatment as prevention — curing infected individuals fast enough to reduce transmission — is most efficient when deployed in high-incidence networks. Acute infection is where those networks are most visible and most accessible, and a 97.7 percent cure rate with a well-defined minimum duration gives clinicians and public health programmes a concrete, actionable protocol. The remaining uncertainties, chiefly the exact optimal duration and the need for randomised confirmation, are now sharply defined questions rather than open-ended ones, and the authors’ call for duration-comparison trials provides the roadmap for answering them. In the meantime, the message for practice is straightforward: acute hepatitis C is highly curable with interferon-free dual therapy, cure does not depend on HIV status or on the particular dual regimen chosen, and eight weeks is the duration at which the evidence currently coheres.

Subject of Research: Efficacy of interferon-free dual direct-acting antiviral regimens and treatment duration for acute hepatitis C virus infection

Article Title: Efficacy of direct-acting antiviral regimens for acute HCV infection: a systematic review and meta-analysis

Article References: Mansour, N., Elbarody, R. M. F., & Kamel, A. M. (2026). Efficacy of direct-acting antiviral regimens for acute HCV infection: a systematic review and meta-analysis. Virology Journal. https://doi.org/10.1186/s12985-026-03307-x

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03307-x

Keywords: hepatitis C, acute HCV infection, direct-acting antivirals, sustained virological response, SVR12, treatment duration, meta-analysis, systematic review, HIV coinfection, men who have sex with men, people who inject drugs, viral cure