This connection arises from differences in the rates of infection in countries
In at least 2 preprint publications the authors expressed the view
This connection arises from differences in the rates of infection in countries where BCG vaccination is mandatory compared to countries where mandatory vaccination no longer exists or was never implemented in the first place .
In at least 2 preprint publications the authors expressed the view that the " known immunological benefits " of BCG vaccination may be behind the biological mechanism of such observation .