You severely underestimate people's laziness. Having to schedule an appointment for a first jab is already an ordeal for most of them, so for a second one? Hell no. A non-negligeable group of people also think that only one jab offers enough protection in the long run (as it is the case for many other vaccines), so they do not bother to get the second one, in spite of scientific evidence.

Still, I wonder where we're going with the number of injections to be done. How many will we need in 2 to 3 years? 5 or 6? And what about people who are late on their jabs? This is gonna be some real mess. I guess the only way out is finding a functional cure for COVID.