They are exempt. It's "2g" rules (geimpft, genesen), so you can have had it or be vaccinated. For clubs and similar they're introducing 2g+ which means you also need a PCR test.
This is, sadly, something the US government is too dumb to copy. More than half the country already had the disease and they pretend it's not the case.
Lost opportunity for some more confusing naming there, like 2gg or 2g+g or perhaps even 2g².