Not a chance immunity would last a lifetime. The efficacy duration will be measured in months. Here is some data from one study:
“One dose helped protect against hospitalization, with effectiveness peaking about five weeks after immunization at 84% effective at preventing hospitalization.
But the follow-up data available beyond that time is where it gets concerning. Effectiveness peaked and then began to decline, going from 84% effective in the fifth week to 61% effective the following week and then 58% beyond then.
It’s unknown whether that trend would continue beyond that, as that’s all the data the researchers had available to crunch in the study. But the findings suggest that protection starts to wane from a single dose after five weeks or so.”
Here is a link to an Israeli chart which shows the decline in efficacy after the second shot.
https://twitter.com/dvir_a/status/1364240578922360833/photo/1
At a recent investor conference Pfizer said annual vaccination would be necessary and additional booster shots may be given.
In lead bow long immunity will last. Many vaccines require a booster periodically. However recent studies have show. the vaccine is just as effective at 6 months as it was when given