Birk NM, et al. – This work was designed to assess the impact of Bacillus Calmette–Guérin vaccine (BCG) vaccination technique for scarring in a high–income setting, by assessing the associations between the post injection reaction, the wheel size, and the probability of developing a scar, and scar size. As per observations, scarring after BCG vaccination seemed associated with lower infant mortality. In a high–income setting, researchers noticed that correct injection technique was highly important for the development of a BCG scar and that registration of the category of BCG skin reaction (as wheel, bulge, or no reaction) could be used to identify infants at risk of scar failure. Finally, there appeared a positive association of the wheel size with both the probability of getting a scar and scar size.