Nanoparticles as adjuvants for vaccines

PMMA nanoparticle adjuvants can be manufactured in a physicochemically reproducible manner. Their particle size can be controlled within narrow limits. Immunogens may be either incorporated or adsorbed to these nanoparticles. PMMA nanoparticles induced significantly higher and more prolonged antibody responses against a variety of immunogens, including influenza virions and subunit vaccines, BSA, and HIV-1 and HIV-2 split vaccines. In addition, a protective immune response against challenge with live influenza virus was induced and a better stability of the immunogen was observed after incorporation or adsorption of influenza virions or subunits to PMMA nanoparticles. The observation that PMMA did not induce antibodies against gp120 contained in the HIV-2 split vaccine demonstrates that different adjuvants or carriers may be required for different antigens. A combination of two or more different adjuvants or carriers may be necessary to induce the optimal immune response against antigen mixtures as present in most vaccine preparations. PMMA seems to be a safe adjuvant material. It is very slowly biodegradable and has been used in surgery in humans for over 40 years, and now warrants continued investigation as a vaccine adjuvant.