COVID-19 Vaccine Development: Challenges and Current Scenarios

The ongoing situation of COVID-19 pandemic entails us towards the development of a prophylactic vaccine as a public health priority. The emergence of SARS-CoV-2 in Wuhan, China during December 2019 marked the third introduction of a highly pathogenic Coronavirus into human population in the twenty-first century. Knowledge from the former vaccine candidates of SARS-CoV and MERS-CoV has unlocked the door for the developers to accelerate the global vaccine development pathway for ongoing COVID-19 pandemic, soon after the online publication of SARSCoV- 2 genomic sequence. The vaccine development pipeline for COVID-19 shows a promising result by utilizing various platforms (nucleic acid, viral vector, recombinant protein, live attenuated viruses, inactivated viruses and virus like particles) with different strategies. Surprisingly till now, we have about 190 vaccine candidates in the clinical and pre-clinical pipeline till 31st August 2020. Approximately, 39 of these vaccine candidates are impending into the human clinical trials after showing significant safety data in preclinical studies of which, 8 vaccine candidates are running in final phase3 stage. Three of them have got an emergency approval for limited or early use. At least 8 candidate vaccines have been developed from India, from which 2 of them have entered phase2 trials. Already existing tuberculosis vaccines are also being tested in clinical trials bridging the gap before a potential COVID-19 vaccine is developed. This chapter highlights the obstacles for implementation of vaccine development for SARS-CoV-2. One of the impediments is identification of high-risk population including frontline health care workers, elderly individuals and persons with pre-existing chronic diseases. We have also provided a comprehensive overview about the COVID-19 vaccine candidates that are in preclinical and clinical stages of development. Thus, fast track clinical trials of many candidates are implemented in different geographical regions promising a prophylactic vaccine against SARS-CoV-2.

Keywords: COVID-19, Clinical trial, Clinical pipeline, Challenges, SARS CoV- 2, Pre-clinical trial, Vaccine development.