Are you going to take the vaccine?

[LeiwoUnion]

   Isn’t the attraction by a magnet due to the metals in the nanobots that are included in the liquid?

Eh, that would be silly. The so called nanobots are not made of ferromagnetic metals; they are usually made of organic materials, sometimes silicone based chemistry. A synthetic 'virus' or other type of drug carrying particle is a common type of 'nanobot'. These can be designed so that they, for example, seek certain tissues before releasing their contents (whatever they are), or they could attach to certain surface features of cells or other biological structures. I've literally had studies about them and I'm qualified to design these types of functional nanoparticles, although never did it professionally as my duties lied elsewhere (stem cell engineering). The scifi type of nanobot is ET tech and is not in wider circulation for human use as far as I know.