Maybe there is no need to complicate things by thinking about nano tech and advanced technology in the jabs. Maybe this one is just to give as many people cancer as possible because that is a type of death which they can easily deny. Steadily increasing rates of cancer, "could be anything" they'll say.

Moreover, with Earth's weakening magnetic field during the Pole shift, that will theoretically bombard Earth with far more space radiation than people are used to. It could be a one two punch, weakening people's immune systems and then kill them off with cancer. Not everyone of course, but who knows, perhaps hundreds of millions or more.

Maybe the full roll out of the more advanced tech comes in response to this first wave of death. Who knows and hard to say, but just thought I'd speculate here.