It's not the vaccine but the body that dictates what happens and at what rate in response to it.
It would be possible to be vaccinated tomorrow (Friday) but fall ill if infected at the weekend because the body has not yet had time to build up the defence.
That's what has been reported multiple times Durdle. I guess every body is different so the rate at which the antibodies develop is different among us. I wonder if age has anything to do with it? Does it take LONGER for us old folks to develop protection? Don't thing slow down as we age? I'll ask. Thank you for your reply! :)