The development of a new crown vaccine by the Chinese team has confirmed the prevention potential in non-human primate models.

In their paper, the study authors noted that the combination of the new coronavirus's binding domain (RBD) with the host cell's binder angiotensin-converting enzyme 2 (ACE2) is the most critical step in its infection process.
to minimize potential side effects while stimulating maximum immunogenicity, the researchers envision finding the smallest tingling protein fragments as antigens.
In this study, scientists used several different parts of the S protein to create several candidate vaccines, and after testing and comparison, they finally confirmed that RBD was the largest virus in and out of the immunogenicity compared to the extracellular domain proteins (ECD), S1 sub-base and S2 sub-base of the S protein.
, the team eventually used an amino acid sequence numbered 319-545 in RBD to produce antigens.
the sequence design of the vaccine (Photo Source: Resources) To produce these recombinated proteins, the team used a rod virus expression vector system for protein expression.
paper notes that vaccines produced by this technique often have a properly folded protein composition and are suitable for commercial-scale vaccine production and have been used in a number of approved cervical cancer vaccines and influenza vaccine products.
In animal trials of recombinant RBD protein candidate vaccines, mice, rabbits, and macaques were shown to have elevated IgG and IgM antibodies in their bodies against recombinant RBD after just 7 or 14 days of receiving only one injection.
in addition to recombinant RBD protein itself can effectively induce the production of specific antibodies, experiments show that the addition of adsage can significantly enhance the induction effect, the production of higher levels of specific antibodies.
in-body cell experiments have shown that serum obtained from immune animals can block the combination of RBD with ACE2 expressed on the cell surface, and almost 100 percent of the SARS-CoV-2 protovirus (only the virus shell without viral nucleic acids).
Vaccine has achieved good protection in mouse models (Photo Source: References) And more importantly, in the anti-virus experiments of non-human primate models, this candidate vaccine has shown the protective effect of blocking new coronavirus infections.
researchers vaccinated macaques twice in 7 days at doses of 20 to 40 μg per dose.
then, in the first vaccination of 28 angels they were exposed to the live new coronavirus.
antibodies to live viruses can be detected in vaccinated macaques, and they are fully protected, with no viral nucleic acid detected in either pharynx swabs or lung tissue.
, animals showed clear signs of viral infection in two control groups that received physiological saline or only adverb injections.
it's worth noting that these animal trials have also shown that the recombinant RBD candidate vaccine does not trigger antibody dependence enhancement (ADE) or cause neo crown pneumonia.
concluded in their paper, the research on the candidate vaccine "highlights the importance of the S protein RBD domain in the design of the new crown vaccine and provides the basis for the development of vaccines to induce antibodies against RBD."
addition, the researchers believe that vaccine production techniques using recombinated proteins have a viable precedent for large-scale supply and commerce, which could support further development of this candidate vaccine.
: s1' Jingyun Yang et al., (2020) A vaccine targeting the RBD of the S protein of SARS-CoV-2 induces protective immunity. Nature. DOI: