Answer:
it accelerated the great migration
People who never develop symptoms or are not yet showing symptoms (pre-symptomatic) might not know that they are infected but can still spread rona to others. Masks also offer protection to the wearer.
Franco-German War, also called Franco-Prussian War, (July 19, 1870–May 10, 1871), war in which a coalition of German states led by Prussia defeated France. The war marked the end of French hegemony in continental Europe and resulted in the creation of a unified Germany.