Disclosed is an immunity inducer. The immunity inducer comprises virus like particles; the virus like particles comprise a virus-derived outer coat protein and an antigen-bound protein comprising an exogenous antigen; the outer coat protein constitutes an outer coat of the virus like particles, and the antigen-bound protein is comprised in the outer coat; and the virus like particles induce an immune effect of a living body on the antigen.

Provided are particles of nucleic acid origami structure encapsulated by at least twelve capsid units, compositions comprising the same and uses thereof for delivery of nucleic acids to target cells.