Development of Spike Receptor-Binding Domain Nanoparticles as a Vaccine Candidate against SARS-CoV-2 Infection in Ferrets
Young‐Il Kim, Do-Kyun Kim, Kwang-Min Yu, Hogyu David Seo, Shin-Ae Lee, Mark Anthony B. Casel, Seung‐Gyu Jang, Stephanie Kim, WooRam Jung, Chih‐Jen Lai, Young Ki Choi, Jae U. Jung
Abstract
-bullfrog ferritin nanoparticles as an antigen delivery system. RBD-ferritin protein purified from mammalian cells efficiently assembled into 24-mer nanoparticles. Sixteen- to 20-month-old ferrets were vaccinated with RBD-ferritin nanoparticles (RBD nanoparticles) by intramuscular or intranasal inoculation. All vaccinated ferrets with RBD nanoparticles produced potent neutralizing antibodies against SARS-CoV-2. Strikingly, vaccinated ferrets demonstrated efficient protection from SARS-CoV-2 challenge, showing no fever, body weight loss, or clinical symptoms. Furthermore, vaccinated ferrets showed rapid clearance of infectious virus in nasal washes and lungs as well as of viral RNA in respiratory organs. This study demonstrates that spike RBD-nanoparticles are an effective protein vaccine candidate against SARS-CoV-2.