One year update on the COVID-19 pandemic: Where are we now?

Abstract

We are living through an unprecedented crisis with the rapid spread of the new coronavirus disease (COVID-19) worldwide within a short time. The timely availability of thousands of SARS-CoV-2 genomes has enabled the scientific community to study the origin, structures, and pathogenesis of the virus. The pandemic has spurred research publication and resulted in an unprecedented number of therapeutic proposals. Because the development of new drugs is time consuming, several strategies, including drug repurposing and repositioning, are being tested to treat patients with COVID-19. Researchers have developed several potential vaccine candidates that have shown promise in phase II and III trials. As of 12 November 2020, 164 candidate vaccines are in preclinical evaluation, and 48 vaccines are in clinical evaluation, of which four have cleared phase III trials (Pfizer/BioNTech's BNT162b2, Moderna's mRNA-1273, University of Oxford & AstraZeneca's AZD1222, and Gamaleya's Sputnik V vaccine). Despite the acquisition of a vast body of scientific information, treatment depends only on the clinical management of the disease through supportive care. At the pandemic's 1-year mark, we summarize current information on SARS-CoV-2 origin and biology, and advances in the development of therapeutics. The updated information presented here provides a comprehensive report on the scientific progress made in the past year in understanding of SARS-CoV-2 biology and therapeutics.

Keywords: COVID-19; Coronavirus; Drug repurposing; Outbreak; Pandemic; Pathogenesis; SARS-CoV-2; Therapeutics; Vaccines.

Fig. 1

Schematic representation of SARS-CoV-2 (A) virus structure and (B) genome organization.

Fig. 2

The D614G mutation. (A) Graph showing the increasing frequency of the D614G variant over time. (B) The virus with D614G mutation is associated with increased transmissibility and higher viral loads in COVID-19 patients.

Fig. 3

(A) Schematic structure of a single CoV spike-protein, showing the receptor binding S₁ subunit, membrane fusion S₂ subunit, and transmembrane anchor (TM) emerging from the viral envelope. (B) The domain structure of S-protein, containing the S₁N-terminal transmembrane domain (S₁NTD) S_1-C terminal (S₁CTD) fusion peptide, heptad repeats (HRN and HRC), and protective cleavage sites (S₁/S₂ and S₂). (C) Binding of CoV to the ACE2 receptor on the host cell through the S-protein RBD.

Fig. 4

2D structures of the drugs currently used for the treatment of COVID-19.