BCG and SARS-CoV2 vaccination in mice

I collaborated on this study by Dilhan Perera and colleagues, under the direction of Momar Ndao. The article, published in iScience, explores the effects of prior BCG exposure on the effectiveness in mice of an intranasal adenovirus-based vaccine against SARS-Cov-2, the virus that causes COVID-19.

I was involved in the scoring of lung damage seen in sacrificed mice from the various experimental groups. Obviously, I was blinded to group membership, but I found the assessment to be challenging given the findings of injury were generally mild. As explained in the study discussion:

[a]lthough the C57BL/6 mouse model reflects age- and sex-based differences in human COVID-19 disease, it is not the ideal model for SARS-CoV-2 vaccine studies since these mice do not display all the hallmark features of severe pathology and typically recover from infection.

Nevertheless, Dilhan and his team were able to detect significant differences in certain subgroups, not only based on histological findings, but also on the basis of serological and immunological experiments. These findings are interesting in the context of widespread BCG immunization in many populations throughout the world, especially in the Global South, as well as renewed efforts to expand vaccination for longstanding and emerging diseases.

Read the article in iScience: https://doi.org/10.1016/j.isci.2023.107612