No, at least to Christian Drosten [1], he explained multiple times in his podcast, that it is quite hard to compare antibody titers from different laboratories

No, at least to Christian Drosten [1], he explained multiple times in his podcast, that it is quite hard to compare antibody titers from different laboratories and therefore it is hard to define general safe thresholds. [1]: https://en.wikipedia.org/wiki/Christian_Drosten https://en.wikipedia.org/wiki/Christian_Drosten