Additional challenge that need to be addressed before inverse vaccines can be used in humans are the drug delivery methods. Researchers are exploring different methods to deliver the vaccine, such as microparticles, nanoparticles or engineered viruses, to ensure it reaches their target effectively. -Encapsulation in PLGA microparticles: Protein antigens can be encapsulated into porous PLGA (poly(lactic-co-glycolic acid)) microspheres using methods like "self-healing encapsulation" to achieve sustained antigen release. The PLGA delivery system can help protect the antigens and facilitate their targeted delivery to induce immune tolerance. Antigens and other immunomodulators can be efficiently loaded onto the surface of PLGA microparticles by conjugating them with short peptides. This surface conjugation approach can help retain the integrity of the antigens during the encapsulation process. -Incorporation into polysaccharide (dextran) particles: Before encapsulation into PLGA microparticles, protein antigens can be first loaded into polysaccharide (dextran) glassy particles through freezing-induced phase separation. This two-step process can help improve the loading efficiency and stability of the antigens. Microparticles made of biodegradable polymers like PLGA can provide controlled and sustained release of the encapsulated antigens over time.