At a Glance
Researchers at Colorado State University have generated recombinant BCG (rBCG) strains expressing SARS-CoV-2 immunogens. These rBCG strains have the potential to confer broader and longer-lasting immunity than traditional mRNA vaccines, whole inactivated viruses and recombinant protein-based vaccines. These rBCG strains may also be useful platforms for different viral diseases and antigens. Preliminary studies in established animal challenge models of SARS-CoV-2 infection have indicated protective efficacy and immunogenicity of rBCG vaccines.
Bacillus Calmette–Guérin (BCG) vaccine is a live vaccine primarily used against tuberculosis (TB), created a century ago by attenuation and is the most widely used human vaccine. The BCG vaccine has been noted to improve immunity against a number of viral pathogens and is commonly given to infants, children, and adults in high-risk areas of TB transmission. However, it has recently received attention for its potential to mitigate non-specific immunity of Covid-19. These strains are known to produce long lasting T cell responses, have natural immune enhancing properties, and a remarkable safety recrod. Therefore, it is of great interest to study rBCG strains to formulate a dual vaccine that protects against both TB and SARS-CoV-2, in a single dose.
Colorado State University researchers have successfully shown these rBCG constructs can display various antigens, including the single Spike protein (S) commonly found in available COVID-19 vaccines. These antigens include targets for the nucleocapsid (N), the membrane (M), the envelope (E), and multiple versions of the spike protein (S). Preliminary challenge trials have shown that these rBCG constructs are stable in vivo, and that some of them provide protection with a single dose.
Using this platform technology a single dose of these BCG vaccines have the potential to be modified to confer simultaneous immunity not only to tuberculosis, but also other viral antigens within the same dose.
- Long-term non-specific immunity and specific adaptive immune response
- Will prevent both disease and transmission by controlling virus replication
- Single dose procides protection against two of the deadliest infectious diseases globally, TB and Covid-19
- Over 5 billion doses of the BCG vaccine have been given worldwide for TB, and has wide healthcare approval
- Simple to mass-produce, as it is currently available
- Stable dosages may be freeze dried, which could lead to wider availability for remote areas and countries
- No additional adjucant is necessary to elicit immune response
- Covid-19 vaccine potential, especially in remote areas
- Non-specific immunity
- Adjuvant to increase the immune response of another vaccine
- Other viral diseases may be reduced as well, further studies are underway
Last updated: May 2022