Developmental challenges and some solutions for the Front Runner Covid-19 Vaccines

The emergence of SARS-COVID -19 pandemic has propelled Tthe biotech industry to accelerate the development of several biological modalities.

- Sashi Kasimsetty

Some of the medical entities include but not limited to vaccines, nucleic acids, small molecules, convalescent serum, intravenous immunoglobulin (IgG) and monoclonal antibodies (mAbs) or their coformulation. Among them, vaccination is a preferred approach for prevention and treatment of COVID-19 induced disease, however the vaccine evolution is plagued by time constrains and manufacturing hurdles. The massive economic and social impact of corona virus has propelled the scientific and government organizations to accelerated the vaccine development. Figure 1 demonstrates multiple platforms of vaccine models targeted against the COVID-19 pandemic causing virus, amid that race two types of vaccine technologies appeared as front runners 1) Non-replicating viral vector (Gene therapy) and 2) Nucleic acid (mRNA) based, where the former delivers the target antigen to the antigen-presenting cells via adenoviral vector while the later via mRNA packed lipid nano-particles.

The vaccine candidates advanced through both platforms express neutralizing antibodies that target the spike protein of the coronavirus and inhibits its binding to the human ACE2 protein and prevent infection. ChAd Ox1 viral vector developed by University of Oxford in collaboration with AstraZeneca is the prime example of non-replicating gene therapy-based vaccine, while the Moderna's mRNA SARS COV-2 vaccine candidate (mRNA-1273) is an exemplary for nucleic acid-based vaccine.