The simple answer to the question of how long immunity to the SARS-CoV-2 virus from vaccination will last is, "We don't know." The simple reason for this simple answer is that the vaccines began testing in March (Moderna), April (Pfizer), and July (J&J) last year. The earliest test participants still have meaningful concentrations of antibodies, and it is also known that the vaccines cause T-cell responses, meaning that recipients' immune systems "know" how to create appropriate antibodies.
Fauci's problem in this is that he has arrogant immunity against saying, "I don't know."
