An overview of immunological response, anti-viral therapy and vaccine development against severe acute respiratory syndrome coronavirus (Sars-cov)-2

Abstract

SARS-CoV-2, the causative agent of COVID-19 disease belongs to the group beta-coronavirus, which have infected around 120 million people so far with a 2.65 million death toll worldwide. Coronaviruses are enveloped viruses having positive sense, single-stranded RNA genome (26-32 kb size). This paper mainly reviews/focuses on the existing development on the vaccination and drugs developed against severe acute respiratory syndrome coronavirus (SARS-CoV). SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), and the novel SARS-CoV-2 have come out as highly fatal strains of coronavirus for human beings. Novel SARS-CoV-2 requires angiotensin-converting enzyme 2 (ACE2) as its foothold receptor to gain entry into the host cells. Infected patients develop symptoms of fever, nonproductive cough, fatigue, dyspnea, sometimes diarrhoea and radiographic evidence of pneumonia. The immune system reacts violently against the virus spread inside the body which gives rise to a condition known as a cytokine storm. The potential anti-viral medicines suggested for COVID-19 treatment were hydroxychlo-roquine, Lopinavir/Ritonavir etc. which showed some combined effects, positive and negative. Many vaccines candidates are under different phases of trials all over the world against SARS-CoV-2. The main cause which enabled the quick development of vaccine technologies against SARS-CoV-2 was that an already established knowledge of the structure and function of its close associates namely SARS and MESRS was present. Molecular platforms used in vaccine development against SARS-CoV-2 are live attenuated vaccines, DNA based vaccines, RNA based vaccines, protein subunits and replicating viral vector vaccines.