The BCG tuberculosis vaccine boosts the production of immune cells and this may explain how it protects newborns from dying of sepsis
Source:
https://www.newscientist.com/article/2242866-bcg-vaccine-helps-fight-infections-by-boosting-immune-cell-production/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home