>>The story also asks what happens to the lipid nanoparticles<<

these lipid particles are incorporated into the cell membrane during vesicular fusion. Expression of the mRNA results in S protien being expressed on the surface of this cell, Antibodies of complementary clonal type bind to this spike in numerous locations the now adulterated cell is labelled as antigenic thus is destroyed by macrophages, the pieces of this cell are then compared to the self/nonself portfolio of patterns and further antibodies are produced.

all the while this cell is in distress due to the presence of foriegn nucleotides and this incurrs an interferon mediated response that spreads among cells and likewise induces interferon response