Related Experiment Video
Updated: Apr 27, 2026
Stem Cell-Derived Viral Ag-Specific T Lymphocytes Suppress HBV Replication in Mice
Published on: September 25, 2019
Protective immunity against hepatitis C: many shades of gray
Mohamed S Abdel-Hakeem1, Naglaa H Shoukry2
1Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) , Montréal, QC , Canada ; Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal , Montréal, QC , Canada ; Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University , Cairo , Egypt.
Insights
Hepatitis C virus (HCV) clearance depends on host genetics and immune responses. Understanding protective immunity, especially T cell and antibody responses, is crucial for developing an effective HCV vaccine.
Area of Science:
- Immunology
- Virology
- Hepatology
Background:
- Hepatitis C virus (HCV) infection frequently leads to chronic liver damage, with spontaneous viral clearance occurring in only about 25% of cases.
- Despite advancements in direct-acting antivirals, an effective vaccine against HCV is still lacking, posing ongoing challenges for new infections and reinfections, particularly in high-risk populations and developing nations.
- The outcome of acute HCV infection is a complex interaction between host genetics, viral factors, and the host's immune system.
Purpose of the Study:
- To review the correlates of protective immunity during acute Hepatitis C virus (HCV) infection and upon viral reexposure.
- To explore the role of both T cell and antibody responses in controlling HCV infection.
- To discuss the implications of these findings for the development of an HCV vaccine.
Main Methods:
- Review of existing human and chimpanzee studies on HCV-specific CD4 and CD8 T cell responses.
- Analysis of recent data on the role of antibody responses in HCV infection.
- Examination of studies in high-risk cohorts identifying correlates of protection during real-world exposures and reinfections.
Main Results:
- HCV-specific CD4 and CD8 T cell responses are essential for preventing viral persistence.
- Antibody responses appear to play a more significant role in controlling HCV than previously recognized.
- Individuals who spontaneously clear acute HCV develop long-lived memory T cells, conferring protection against persistent infection upon reexposure.
Conclusions:
- Protective immunity against Hepatitis C virus (HCV) involves a complex interplay of T cell and antibody responses.
- Understanding these immune correlates is vital for developing effective prevention strategies, including a much-needed HCV vaccine.
- Further research is needed to resolve outstanding questions regarding key protective correlates and their application in vaccine design.
Abstract:
The majority of individuals who become acutely infected with hepatitis C virus (HCV) develop chronic infection and suffer from progressive liver damage while approximately 25% are able to eliminate the virus spontaneously. Despite the recent introduction of new direct-acting antivirals, there is still no vaccine for HCV. As a result, new infections and reinfections will remain a problem in developing countries and among high risk populations like injection drug users who have limited access to treatment and who continue to be exposed to the virus. The outcome of acute HCV is determined by the interplay between the host genetics, the virus, and the virus-specific immune response. Studies in humans and chimpanzees have demonstrated the essential role of HCV-specific CD4 and CD8 T cell responses in protection against viral persistence. Recent data suggest that antibody responses play a more important role than what was previously thought. Individuals who spontaneously resolve acute HCV infection develop long-lived memory T cells and are less likely to become persistently infected upon reexposure. New studies examining high risk cohorts are identifying correlates of protection during real life exposures and reinfections. In this review, we discuss correlates of protective immunity during acute HCV and upon reexposure. We draw parallels between HCV and the current knowledge about protective memory in other models of chronic viral infections. Finally, we discuss some of the yet unresolved questions about key correlates of protection and their relevance for vaccine development against HCV.
Related Concept Videos
01:25Hepatitis
01:29Immune Response Against Viral Pathogens
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
01:28Viral Hepatitis I: Introduction
01:23Immunological Memory
What is Immunological Memory?
Immunological memory is an integral function of the immune system that allows it to recognize and react more rapidly and effectively to pathogens previously encountered. This feature...
01:31Active versus Passive Immunity
Active Immunity
Active immunity refers to the resistance one develops...
01:27Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...