- December 3, 2021
- Posted by: admin1
- Category: DPN Topics
Subject – Science and Tech
Context – Indonesia’s recent approval for emergency use of the first protein-based vaccine developed by Novavax is welcome news
- Unlike the never-used-before platforms of the mRNA and viral vector vaccines, recombinant protein-based technology is time-tested and widely used for many viral diseases. Protein-based vaccines, while slow to develop, are more stable at higher temperatures, easy to scale up, highly cost-effective, safe, and efficacious.
- The first protein-based vaccines relied on natural sources of antigens. In this regard, the first hepatitis B vaccine is unique in using a human source (plasma) for the vaccine antigen.
- Rather than injecting a whole pathogen to trigger an immune response, subunit vaccines (sometimes called acellular vaccines) contain purified pieces of it, which have been specially selected for their ability to stimulate immune cells.
- Because these fragments are incapable of causing disease, subunit vaccines are considered very safe.
- There are several types:
- Protein subunit vaccines contain specific isolated proteins from viral or bacterial pathogens;
- Polysaccharide vaccines contain chains of sugar molecules (polysaccharides) found in the cell walls of some bacteria;
- Conjugate subunit vaccines bind a polysaccharide chain to a carrier protein to try and boost the immune response.
- Only protein subunit vaccines are being developed against the virus that causes COVID-19.