Abstract: The invention relates to the field of immunity against coronaviruses. In this respect, the invention provides a lentiviral-based immunogenic agent that is suitable for use in boost or target immunization treatment in a subject, in particular a human subject, who had previously developed an immunity against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) based on: (i) vaccination with the first generation of vaccines against SARS-CoV-2 infection or disease such as a protein, an mRNA, an adenovirus, an inactivated virus or a protein subunit vaccine composition against SARS-CoV-2 infection or disease, in particular a protein- or an mRNA-based vaccine, or (ii) SARS-CoV-2-induced or correlated disease.

Abstract: The invention discloses a lentiviral vector and lentiviral vector particles for treating hepatitis B infection. The lentiviral vector and particles of the invention contain a nucleotide sequence coding an hepatitis B virus antigen. The large S antigen of hepatitis B virus was in particular selected as candidate and can be applied in pharmaceutical compositions or vaccines for treating and/or preventing hepatitis B virus infection or treating and/or preventing diseases caused by hepatitis B virus infection, which has excellent therapeutic and preventive effects in subjects in need thereof.