Fighting the flu: The surprising power of a century-old vaccine for tuberculosis

As Canada’s flu season collides with record strep A cases and ongoing COVID-19 concerns, a new study is shedding light on our understanding of respiratory immune responses. Scholars from the Research Institute of the McGill University Health Centre (RI-MUHC) have discovered a surprising facet about a century-old vaccine for tuberculosis, Bacillus Calmette Guérin (BCG). The study, published in the journal Nature Immunology , uncovered a previously unknown mechanism that extends the vaccine’s shield to combat influenza A virus-the most prevalent flu strain.

"The immune interactions involved here can ’train’ the lungs, which are frequently exposed to infectious agents in the environment. If we can map out the protective immune pathways involved in the lungs, this will revolutionize our conceptual and clinical approaches in developing vaccines against infections, including emergent respiratory viruses," explains lead author Maziar Divangahi, a pulmonary immunologist, a senior scientist at the RI-MUHC, and a Professor of Medicine at McGill University. The discovery paves the way for future studies to assess whether BCG could be used to prevent other emergent viruses. Notably, research on the vaccine’s protection against COVID-19 has had promising results.

About the study

"BCG immunization induces CX3CR1  effector memory T cells to provide cross-protection via IFN-mediated trained immunity" by Kim Tran et al. was published in Nature Immunology.

About McGill University 

Founded in Montreal, Quebec, in 1821, McGill University is Canada’s top ranked medical doctoral university. McGill is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning three campuses, 12 faculties, 14 professional schools, 300 programs of study and over 39,000 students, including more than 10,400 graduate students. McGill attracts students from over 150 countries around the world, its 12,000 international students making up 30% of the student body. Over half of McGill students claim a first language other than English, including approximately 20% of our students who say French is their mother tongue.