Figure 4.

Strategies for the development of nanovaccines against SARS-CoV-2.

(A) The spike protein S that is present at the surface of the virus is unique for SARS-CoV-2 and has been used as a vaccine target by different laboratories. Nanovaccines comprise S protein mRNA. although the corresponding DNA sequence can also used. S proteins are often broken down into fragments that can also be used as antigens. (B) (i) The Astrazeneca, Sputnik V, and Johnson & Johnson vaccines use conventional adenovirus-mediated DNA transfer method to express SARS-CoV-2 S protein at the site of inoculation. (ii) The Moderna and Pfizer vaccines introduce S mRNA by means of lipid nanoparticles, leading to local synthesis. (iii) Novavax contains S protein embedded in a nanoparticle system, whereas (iv) Bharat Biotech and Sinopharm used a conventional inactivated whole virus vaccine. Abbreviation: SARS-CoV-2, severe acute respiratory syndrome coronavirus-2.