PROSPECTS OF SARS-CoV-2 VACCINES AND THEIR LANDSCAPE

Abstract

Severe Acute Respiratory Syndrome Corona Virus -2 (SARS-CoV-2), puzzled the whole world with its diverse, unique clinical spectrum, and unprecedented transmission dynamics. The disease caused by this virus is named as Coronavirus disease-19 (COVID-19), reported first time in Wuhan, China, in December 2019. It had spread to almost all countries of the world disrupting the health and economy of many countries. It was the recent zoonotic spillover disease reported in humans from the Coronavirus group, without proper medicine and non-existence of prior immunity, this disease posed a challenge to both the scientific and medical fraternity. The search for safe, effective drugs to treat the disease and vaccines against the causative agent SARS- CoV-2 had begun all over the world with public and private partnerships. Many countries are part of the solidarity trail for identifying the effective drugs, clinical trials and vaccines for this global pandemic. Here in this review, we are focussing on the different vaccine production platforms being used in the preparation of vaccines against SARS-CoV-2, their current status and prospects. Vaccine production technology significantly advanced in recent times by imbibing the cutting edge technologies such as nucleic acid based technologies such as DNA/RNA/Codon deoptimization and availability of safe and effective viral vectors produced through rDNA technology. The availability of complete genome sequence of SARS-CoV-2, geared up for the production of vaccine candidates based on these new vaccine production platforms, and in a record time of 4-5 months, these vaccine candidates entered in human clinical trials for the evaluation of safety and efficacy. Prior knowledge on SARS and MERS-CoV’s structural and genomic features, vaccine production platforms used in making vaccines against them greatly augmented in the SARS-CoV-2 vaccine efforts. As per World Health Organization (WHO) a total of202 vaccine candidates are under developing for SARS-CoV-2, among them 47 entered in clinical trials and 156 are in the preclinical stage. These vaccines are prepared by an amalgamation of both new and old traditional vaccine production platforms such as nucleic acid base platforms, inactivated, live attenuated, recombinant viral vectors, protein and peptide-based vaccines. The success of these vaccine candidates lies in the generation of effective immune response for SARS-CoV-2 across all age groups and people with co-morbidities. We briefly summarize the different strategies of SARS-CoV-2 vaccine production and their prospects with an emphasis on different routes of administration and added a basic mathematical model depicting the importance of vaccination for any pandemic.