New publications
TherVacB: Therapeutic Vaccine for Chronic Hepatitis B Begins Clinical Trials
Last reviewed: 27.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
In June 2025, the first dose of TherVacB therapeutic vaccine against chronic hepatitis B was administered in the first clinical trial involving patients. In a previous study in healthy volunteers, the vaccine demonstrated a favorable safety profile and induced the desired immune response.
In the current study, patients with chronic hepatitis B are receiving a therapeutic vaccine in clinics in five countries to assess its safety, tolerability, and efficacy.
Chronic hepatitis B is an infectious disease that affects 254 million people worldwide. It significantly increases the risk of liver damage, cirrhosis, and liver cancer. Although there are preventive vaccines and antiviral drugs, there is still no radical treatment. Modern drugs suppress the virus, but require lifelong use and are not available to all patients. According to the WHO, hepatitis B claims 1.1 million lives each year.
“After 13 years of research, the start of clinical trials of TherVacB in patients is an exciting moment, as it is a critical step towards a possible cure for chronic hepatitis B,” says Ulrike Protzer, professor of virology at the Technical University of Munich and director of the Institute of Virology at Helmholtz Munich, the author of the vaccine.
“This vaccine is designed to activate the natural immune response so that the body can finally eliminate the virus on its own,” she adds, who is also coordinator of the hepatitis research area at the German Center for Infectious Diseases (DZIF).
The vaccine covers almost all strains of the virus
TherVacB uses a so-called heterologous prime-boost strategy: first, viral proteins are introduced to “prime” the immune system, followed by a modified viral vector that enhances the cellular immune response. This approach stimulates both antibody and T-cell immunity directed against the hepatitis B virus. The vaccine is also tailored to cover more than 95% of global HBV strains, making it potentially effective for more than 250 million infected people worldwide.
The current clinical trial is being sponsored by the Ludwig Maximilian University Hospital in Munich and led by Professor Michael Hölscher, Director of the Institute for Infectious Diseases and Tropical Medicine and Coordinator of the DZIF in Munich. The trials are being conducted in clinics in Germany, Italy, Spain, England and Tanzania.
They are aimed at assessing the safety, tolerability and immune activity of the vaccine in patients with chronic hepatitis B, whose infection is currently controlled with antiviral drugs. A total of 81 patients are participating in the study in two phases.
- In the first part (Phase 1b), participants are given increasing doses of the vaccine components to determine the safest and most effective dosage.
- In the second part (phase 2a), the selected optimal dose is tested in a larger number of patients to confirm its safety and assess its ability to induce the immune response needed to control the virus.
"The results could change the global strategy to combat hepatitis B"
If the trial is successful, TherVacB could be a breakthrough in the treatment of chronic hepatitis B. The ability to induce a functional immune response in already infected patients could lay the foundation for a true cure—something no existing treatment offers.
“The results of this trial may not only determine further steps in clinical development, but also redefine the global strategy for combating hepatitis B – especially in regions with a high prevalence of the disease and limited access to current treatments,” says Professor Hölscher.