How long does the protection of the approved mRNA vaccines last?

This is not yet exactly clear. However, it is certain that the efficacy of the mRNA vaccines was tested two to three months after vaccination. This suggests that vaccine protection can be expected to last for at least that long. And while long-term data are still unavailable, those who volunteered to participate in these studies remain under observation. This will enable researchers to assess post-vaccination protection for ever increasing periods of time.