Chronic hepatitis B, caused by an infection with the hepatitis B virus (HBV), is an inflammatory liver disease that leads to tissue damage. A persistent HBV infection, where the immune system cannot completely eliminate the virus, can lead to ongoing liver damage, cirrhosis and even liver cancer. HBV infections have a high prevalence worldwide, especially in areas where transmission is mainly from mother to child during birth. Transmission occurs through blood, sexual contact or from mother to newborn. The latter is the most common cause of chronic infection. The World Health Organization (WHO) estimates that around 296 million people worldwide are living with chronic HBV infections; every year around 820,000 people die as a result. Current treatment options include antiviral drugs, which reduce the viral load and liver inflammation but do not provide a cure. In addition, nucleotide analogs, which are the current standard of care, must be taken daily and are not widely available worldwide. Consequently, there is an urgent need for a cure.

After extensive preclinical testing and manufacturing of the vaccine according to "Good Clinical Practice" guidelines, a key milestone was reached on January 25, 2024, when the first participant was enrolled in the clinical trial of TherVacB. This is an open-label phase 1a study with increasing doses to investigate the safety and immunogenicity of TherVacB in 24 healthy participants aged 18 to 65 years. With the University Medical Center Hamburg-Eppendorf as sponsor and Prof. Dr. Marylyn Addo as principal investigator, the Department of Infectious Diseases and Tropical Medicine at the LMU Klinikum München under the direction of Dr. Mirjam Schunk is responsible for conducting the clinical trial. At the same time, preparations are underway to apply for the phase 1b/2a "first-in-patient" study, which will investigate safety and efficacy in patients with chronic hepatitis B. This study is to be conducted in Germany, Italy, Spain, England and Tanzania and is being funded by the European Union as part of a "Horizon 2020" research project.