A SARS-CoV-2 ferritin nanoparticle vaccine elicits protective immune responses in nonhuman primates.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants stresses the continued need for next-generation vaccines that confer broad protection against coronavirus disease 2019. We developed and evaluated an adjuvanted SARS-CoV-2 spike ferritin nanoparticle (SpFN) vaccine in nonhuman primates. High-dose (50-μg) SpFN vaccine, given twice 28 days apart, induced a T helper cell 1 (T_H1)–biased CD4 T_H response and elicited neutralizing antibodies against SARS-CoV-2 wild type and variants of concern, as well as against SARS-CoV-1. These potent humoral and cell-mediated immune responses translated into rapid elimination of replicating virus in the upper and lower airways and lung parenchyma of nonhuman primates after high-dose SARS-CoV-2 respiratory challenge. The immune response elicited by SpFN vaccination and resulting efficacy in nonhuman primates support the utility of SpFN as a vaccine candidate for SARS-causing betacoronaviruses. A nanoparticle vaccine for SARS-CoV-2: Despite the early success of authorized and approved SARS-CoV-2 vaccines, improved vaccines that can elicit robust cellular and humoral immune responses are still essential for combating the ongoing COVID-19 pandemic. Here, Joyce et al. developed a SARS-CoV-2 spike protein ferritin nanoparticle (SpFN) vaccine. Nonhuman primates vaccinated with two doses of SpFN plus adjuvant separated by 28 days developed potent SARS-CoV-2–specific B and T cell responses, which conferred protection against SARS-CoV-2 challenge. Serum isolated from vaccinated animals neutralized several variants of concern, including the delta variant. Together, these data support further development of this adjuvanted SpFN vaccine. [ABSTRACT FROM AUTHOR]