Immunogenicity of a vaccinia virus-based severe acute respiratory syndrome coronavirus 2 vaccine candidate

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines provide essential tools for the control of the COVID-19 pandemic. A number of technologies have been employed to develop SARS-CoV-2 vaccines, including the inactivated SARS-CoV-2 particles, mRNA to express viral spike protein, recombinant spike proteins, and viral vectors. Here, we report the use of the vaccinia virus Tiantan strain as a vector to express the SARS-CoV-2 spike protein. When it was used to inoculate mice, robust SARS-CoV-2 spike protein-specific antibody response and T-cell response were detected. Sera from the vaccinated mice showed strong neutralizing activity against the ancestral Wuhan SARS-CoV-2, the variants of concern (VOCs) B.1.351, B.1.617.2, and the emerging B.1.1.529 (omicron). This finding supports the possibility of developing a new type of SARS-CoV-2 vaccine using the vaccinia virus vector.

Rapid and sensitive one-tube detection of mpox virus using RPA-coupled CRISPR-Cas12 assay

“…Recombinant vaccinia virus (VACV-N3R/N4R) bearing mpox virus genes N3R and N4R were generated by homologous recombination as reported. 52 Briefly, mpox virus N3R and N4R sequences without ATG start codon were inserted into thymidine kinase (TK) locus of the VACV Tiantan strain by homologous recombination. Recombinant vaccinia virus was obtained with five rounds of plaque purification and the insertion of N3R and N4R into the viral genome was confirmed by PCR and DNA sequencing.…”

Exploration of mRNA nanoparticles based on DOTAP through optimization of the helper lipids

“…SARS‐CoV‐2 spike antibody was detected using the SARS‐CoV‐2 Spike S1 Antibody Titer Assay Kit (Mouse) (Sino Biological Inc., KIT007) according to the instructions of the manufacturers. [ 35 ] Briefly, 100 mL of serum diluted 4‐fold in a dilution buffer was added to spike S1‐precoated microplates and incubated at room temperature for 2 h. Following the addition of diluted horseradish peroxidase (HRP)‐rabbit anti‐mouse IgG to the plates, the plates were washed and incubated for 1 h at room temperature before substrate was added and then the plates were incubated with substrate solution for 20 min. Finally, the optical density (OD) at 450 nm was measured on the Varioskan Flash microplate reader (Thermo Scientific) after termination with stop solution, and quantification of SARS‐CoV‐2 spike antibody was conducted using a standard curve generated from a dilution series of the corresponding control antibody.…”

“…according to the instructions of the manufacturers. [35] Briefly, 100 mL of serum diluted 4-fold in a dilution buffer was added to spike S1precoated microplates and incubated at room temperature for 2 h.…”