A New Nanoparticle (SpFN) Vaccine Candidate

Researchers have developed a promising new SARS-CoV-2 vaccine candidate that utilizes nanotechnology and shows robust, long-lived immunity in mouse models. According to this new study, the vaccine enhanced the recruitment of APCs (antigen-presenting cells), increased polyfunctional spike-specific T cells, with a bias towards TH1 responses, IFN-γ and TNFα as the dominant cytokines, and more robust SARS-CoV-2 spike-specific recall response and presented broad protection against other coronavirus strains.

The researchers have performed a thorough study of the vaccine-evoked innate and adaptive immune responses in mice against SARS-CoV-2. The study results have been published on a pre-print server. The researchers genetically linked the modified and stabilized prefusion-spike protein of the Wuhan-Hu-1 strain of SARS-CoV-2, to form a ferritin-fusion recombinant protein, which naturally forms a Spike-Ferritin nanoparticle (SpFN). hey then formulated it with either of the two distinct adjuvants used in this study: 1) Army Liposome Formulation containing the saponin, QS-21(ALFQ), and 2) Aluminum Hydroxide gel (Alhydrogel®) (AH).

Notably, the vaccine SpFN+ALFQ is currently in phase 1 clinical trial in the United States, sponsored by the U.S. Army (ClinicalTrials.gov Identifier: NCT04784767).  These findings have demonstrated a novel vaccine platform for SAR-CoV-2 that leverages the innate immune response to induce potent memory-specific antiviral T cells.

Ref link: https://www.biorxiv.org/content/10.1101/2021.04.28.441763v1