Abstract

*Riddhi Goswami, Subhrojyoti Ghosh, Tiyasa Bhuniya, Aritra Paul, Anuvab Dey, Madhurima Koley, Souhardya Bandyopadhyay

ABSTRACT

Severe Acute Respiratory Syndrome Corona Virus 2 (SARS CoV 2), belonging to the Coronaviridae family, is the main cause of COVID 19. Being a positive single-stranded virus, it spreads primarily through cough and sneeze and exerts its downstream effects by binding to angiotensin-converting enzyme 2 (ACE 2) transmembrane protein that controls the renin - angiotensin system. During the prolonged period of intense lockdown, scientists had been trying to devise various effective vaccine strategies against the virus. One of the most direct consequences of these researches is the development of different types of vaccines like DNA vaccines, mRNA vaccines, Viral Vector Vaccines, Protein Subunit Vaccines, Live attenuated vaccines, Inactivated vaccines, Virus-like particle vaccines just to name a few. Some vaccines have claimed efficacies to be as high as 93.5% in case of COVIran vaccines while others have claimed efficacies to be as low as 45%. Many of the internationally acclaimed and approved vaccines have efficacies in the intermediate ranges of 60%-70% like Oxford Astrazeneca vaccine and the Moderna Vaccine. Clinical trials have been conducted on participants from various parts of the world and different countries have approved various vaccines for emergency usages based on the clinical data. At present, 2 mostly used vaccines in India are Covishield and Covaxin. Our review paper takes into consideration the principal vaccines developed in India and in the rest of the world along with their mode of action, the number of doses required, the storage conditions along with claimed efficacy and clinical trial data. This vaccination strategy must be accelerated as much as possible in order to achieve the goal of ?Herd Immunity‘ at the earliest.