Anyone who was once infected with the alpha or delta variant of the corona virus was only briefly immune to renewed infection with Omikron. But omicron protects well against omicron. And protection from serious illness seems to last a long time.
From
Christina Berndt
Omikron has been the game changer. When this coronavirus variant emerged in the winter of 2021/22, a lot changed in the pandemic. Although Omicron is incredibly contagious, it no longer makes people as seriously ill as its predecessors. Only because of this virus variant can you now, three years after the beginning of the pandemic, let go of the corona virus in Germany.