dna immunization 

DNA immunization is one of the most straight-forward approaches to elicit an immune reaction against a foreign protein. Differ from the conventional immunization methods, DNA immunization permits in vivo antigen production, bypassing the time-consuming (sometimes also difficult) processes of immunogens (e.g. peptides and recombinant proteins) synthesis and purification.

https://www.creative-biolabs.com/antibody-production-through-dna-immunization-genetic-immunization.html