[corty]

In Germany, the end-of-summer spread happened due to several factors, bad weather because autumn, lowered restrictions (as were all summer) and start of schools after the summer holidays. There is no single silver bullet to stop the spread (except maybe "prevent all contact"), but there are several factors that need to play together.

However, the lowered restrictions during German summer also had a visible effect, look at the numbers between June 2020 and August 2020 and you will see a distinct rise there. It isn't nearly as bad as in September, but it is there.