[jbd28]

It’s not a binary thing. One virus enters a cell and it makes thousands of copies to spread in the body. Each of those get attacked by the antibodies and T cells pre-generated from the vaccine. No vax or no prior infection and the body is learning while also getting ravaged by the virus.

And as for immunity from infection, your body makes antibodies for the prefusion spike (the free floating form that infects cells), the post fusion spike (after it binds to ACE2), and the nucleocapsid. Since prefusion spikes are what bind to cells for entry, you’d want your immune system focused entirely on attacking that vector. China’s sinovac vaccine generates nucleocapsid antibodies and it’s failing in the face of omicron.