In short
The rBCG-N-RSV vaccine is an investigational recombinant BCG vaccine that expresses the respiratory syncytial virus (RSV) nucleoprotein. It is being developed as a potential vaccine against RSV, a common respiratory virus. One Phase 2 clinical trial is currently authorised to evaluate its safety and immunogenicity in 200 adults over 60 years of age.
Key points
- An investigational recombinant BCG vaccine expressing the RSV nucleoprotein, with no marketing authorisation yet.
- Being studied in one authorised Phase 2 clinical trial in adults over 60 years of age.
- The trial will enrol 200 participants and compare rBCG-N-RSV with conventional BCG vaccine.
- Given as a lyophilisate for solution for injection via the intradermal route.
- Main measures include safety, local and systemic adverse events, and cellular immune responses against mycobacterial and RSV antigens.
What is rBCG-N-RSV?
It is based on the conventional BCG vaccine, which is widely used against tuberculosis, but has been modified to also express the nucleoprotein of respiratory syncytial virus (RSV).
The substance is classified under the therapeutic area of virus diseases. It is supplied by Biothervax SpA and currently has no marketing authorisation in the product records, meaning it is still an investigational substance.
How does rBCG-N-RSV work?
The vaccine is designed to stimulate an immune response against two targets. As a live attenuated BCG vaccine, it is intended to trigger a cellular immune response against mycobacterial antigens. In addition, because it expresses the RSV nucleoprotein, it aims to generate a cellular immune response against RSV as well. The trial measures the production of interferon gamma (IFN-γ) and interleukin-2 (IL-2) by T cells when exposed to purified protein derivative (PPD) mycobacterial antigen and to recombinant RSV nucleoprotein antigen.
Which conditions is it studied for?
- Respiratory syncytial virus (RSV) infection — the vaccine is being developed to potentially protect against RSV, a common virus that can cause serious respiratory illness, particularly in older adults.
How is rBCG-N-RSV given?
The vaccine is formulated as a lyophilisate for solution for injection and is administered by the intradermal route (injection into the skin). In the authorised Phase 2 trial, the dose reported is 0.1 CFU/ml (colony forming units per millilitre).
What do the clinical trials show?
One clinical trial is authorised for rBCG-N-RSV. It is a randomised, double-blind, Phase 2 trial that will compare the rBCG-N-RSV vaccine with conventional BCG vaccine in 200 adults over 60 years of age.
The trial is currently in the authorised status, meaning it has received approval but results are not yet available. The primary outcomes focus on safety and immunogenicity, including the occurrence, intensity, and duration of local solicited adverse events (such as the evolution of the "flare-up" until scar generation), unsolicited adverse events during a 6-month follow-up, changes in blood cell counts and biochemical profile, and T cell production of IFN-γ and IL-2 upon exposure to PPD and RSV nucleoprotein antigens.
What side effects are known?
Side effects are not described in the available registry data. The ongoing Phase 2 trial is specifically designed to evaluate the safety of the vaccine, including local reactions at the injection site and systemic adverse events over a 6-month follow-up period.