Novel virus-like nanoparticle vaccine effectively protects animal model from SARS-CoV-2 infection

Abstract

The key to battling the COVID-19 pandemic and its potential aftermath is to develop a variety of vaccines that are efficacious and safe, elicit lasting immunity, and cover a range of SARS-CoV-2 variants. Recombinant viral receptor-binding domains (RBDs) are safe vaccine candidates but often have limited efficacy due to the lack of virus-like immunogen display pattern. Here we have developed a novel virus-like nanoparticle (VLP) vaccine that displays 120 copies of SARS-CoV-2 RBD on its surface. This VLP-RBD vaccine mimics virus-based vaccines in immunogen display, which boosts its efficacy, while maintaining the safety of protein-based subunit vaccines. Compared to the RBD vaccine, the VLP-RBD vaccine induced five times more neutralizing antibodies in mice that efficiently blocked SARS-CoV-2 from attaching to its host receptor and potently neutralized the cell entry of variant SARS-CoV-2 strains, SARS-CoV-1, and SARS-CoV-1-related bat coronavirus. These neutralizing immune responses induced by the VLP-RBD vaccine did not wane during the two-month study period. Furthermore, the VLP-RBD vaccine effectively protected mice from SARS-CoV-2 challenge, dramatically reducing the development of clinical signs and pathological changes in immunized mice. The VLP-RBD vaccine provides one potentially effective solution to controlling the spread of SARS-CoV-2.

Vaccine booster efficiently inhibits entry of SARS-CoV-2 omicron variant

“…Written informed consent was obtained from all participants. We packaged SARS-CoV-2 pseudoviruses using the omicron spike and used them to enter HEK293T cells stably expressing human ACE2 [ 5 ]. As comparisons, we also packaged two other SARS-CoV-2 pseudoviruses using the spikes from a prototypic strain and delta strain, respectively.…”

A SARS-CoV-2 peptide vaccine which elicits T-cell responses in mice but does not protect against infection or disease

“…Body weights and clinical scores were recorded daily. Clinical disease was assessed using a 6-point scale(31): 0 = normal; 1 = piloerection; 2 = piloerection and kyphosis; 3 = piloerection, kyphosis, and reduced movement; 4 = piloerection, kyphosis, minimal spontaneous movement, +/-labored breathing (humane endpoint); 5 = moribund, dead, or euthanized. On 5 days post infection (DPI), mice were euthanized by an overdose of isoflurane anesthesia, and lungs were collected.…”

“…Gross lung discoloration scores were assigned as follows(31): 0 = normal, pink lungs; 1 = severe discoloration affecting less than 33% of the lung surface area or mild to moderate discoloration affecting less than 67% of the lung surface area; 2 = severe discoloration affecting 34% to 67% of the lung surface area or mild to moderate discoloration affecting 68% to 99% of the lung surface area; 3 = severe discoloration affecting 68% to 99% of the lung surface area or mild to moderate discoloration affecting 100% of the lung surface area; and 4 = severe discoloration affecting 100% of the lung surface area.…”

Nanomaterial-Augmented Formulation of Disinfectants and Antiseptics in Controlling SARS CoV-2

“…As mentioned in previous sections, the main NMs with anti-coronavirus features are Quantum dots, synthetic virus-like particles, nanostructured lipid carriers, polymeric nanocapsules, carbon nanotubes, carbon dots, metal nanoparticles, nanostars, and magnetic nanoparticles (Table 4 ). The effect of Lipid Nanoparticles (LNP) and Virus-Like Particles (VLP) on SARS-CoV-2 have often been investigated in cell line and animal models including HEK 293 T, HeLa, Vero E6, and Freestyle CHO-S cells and animal models like transgenic hACE2 mice, C57BL/6 mice, BALB/C mice, Rhesus macaques, and Syrian golden hamsters (Geng et al, 2021 ; Ma et al, 2020 ) (Table 4 ).…”