They (BioNTech) themselves have only a few in Germany (2 or 3), but it's produced by other companies for them now as well totalling to around seven according to this German source: https://www.pharma-food.de/markt/standorte-corona-impfstoff-.... I say around because not all do the whole production sometimes only parts of it as it seems. Didn't dig very deep into it.