Nanoparticle-encased vaccines can fend off lethal pathogens in animals, and could allow for a swift response to disease outbreaks.
Vaccines made from live virus can elicit long-lasting immunity, but most are slow and laborious to make. Daniel Anderson at the Massachusetts Institute of Technology in Cambridge and his colleagues instead made a fully synthetic vaccine by encasing antigen RNA in a modified-polymer nanoparticle that protected the RNA from degradation.
Single injections of such vaccines against the Ebola virus and the influenza virus, as well as the parasite Toxoplasma gondii, were sufficient to generate immune responses in mice and to protect the animals against otherwise lethal doses of the pathogens.
Vaccines have had broad medical impact, but existing vaccine technologies and production methods are limited in their ability to respond rapidly to evolving and emerging pathogens, or sudden outbreaks. Here, we develop a rapid-response, fully synthetic, single-dose, adjuvant-free dendrimer nanoparticle vaccine platform wherein antigens are encoded by encapsulated mRNA replicons. To our knowledge, this system is the first capable of generating protective immunity against a broad spectrum of lethal pathogen challenges, including H1N1 influenza, Toxoplasma gondii, and Ebola virus. The vaccine can be formed with multiple antigen-expressing replicons, and is capable of eliciting both CD8+ T-cell and antibody responses. The ability to generate viable, contaminant-free vaccines within days, to single or multiple antigens, may have broad utility for a range of diseases.
Source: Nature Magazine