Has the Spring 2020 lockdown modified the relationship between air pollution and COVID-19 mortality in Europe? In three additional countries, air pollution was related to a higher COVID-19 death risk both during and after the lockdown. To sum up, only in 5 countries out of 33 considered there was no significant relationship between air pollution and COVID-19 mortality during the lockdown whereas there was a link after, which supports the hypothesis that diminishing air pollution emissions may be beneficial for the severe forms of COVID-19. [Extracted from the article]