McGill University scientists have demonstrated in mice that the BCG TB vaccine enhances and prolongs the effect of the SARS-CoV-2 vaccine. Results published bioRxiv and is considered preliminary until published in a peer-reviewed scientific journal.
The researchers found that the BCG vaccine alone could not protect animals from SARS-CoV-2. This was demonstrated by no difference between the lungs of vaccinated and unvaccinated mice.
The intranasal SARS-CoV-2 vaccine optimized for mice protected them from the virus, but after six months the oral virus count was the same in infected vaccinated and unvaccinated animals. The number of virus particles was significantly lower among animals pre-vaccinated with BCG.
Scientists suggest that the BCG vaccine improves the body’s response to the SARS-CoV-2 vaccine and its ability to control the virus in the respiratory tract.
In addition, the BCG vaccine increased the effectiveness of the coronavirus vaccine. Researchers believe that BCG may allow the use of a simplified vaccination schedule under certain circumstances.