An overview of viruses discovered over the last decades and drug development for the current pandemic

Abstract

Since the discovery of the yellow fever virus in 1901, thus far, two hundred nineteen viral species are recognized as human pathogens. Each year, the number of viruses causing infections in humans increases, triggering epidemics and pandemics, such as the current COVID-19 pandemic. Pointing to bats as the natural host, in 2019, a genome highly identical to a bat coronavirus (COVID-19) spread all over the world, and the World Health Organization (WHO) officially confirmed it as a pandemic. The virus mainly spreads through the respiratory tract, uses angiotensin-converting enzyme 2 (ACE2) as a receptor, and is characterized by symptoms of fever, cough, and fatigue. Antivirals and vaccines have provided improvements in some cases, but the discovery of a new and diverse variety of viruses with outbreaks has posed a challenge in timely treatments for medical scientists. Currently, few specific antiviral strategies are being used, and many of the effective antiviral drugs and reported active molecules are under vital exploration. In this review, with the details of viral diseases, we summarize the current attempts in drug development, epidemiology, and the latest treatments and scientific advancements to combat the COVID-19 epidemic. Moreover, we discuss ways to reduce epidemics and pandemics in the near future.

Keywords: 3D structure analysis; Covid-19; HIV; MERS-CoV; SARS; Viruses.

Fig. 1

a) Aligned 3D structures of the selected proteins brown is 4rsp.pdb, blue 2gx4.pdb and green 7c8t.pdb, b) 3D structure in which red color indicates helics, green β turns, purple ɤ turns brown β hair pin region, c & d) structure according to the showing the substrate binding region.

Fig. 2

Sequence alignment for the proteins 4RSP.pdb, 2GX4.pdb and 7C8T.pdb. Colored boxes indicate the similarity with the 3D structures. Purple shows highly conserved residues, while completely conserved are shown in red.

Scheme 1

Schematic view of the transmission of viruses and illustration of 3D similarity of viral enzymes

Fig. 3

a) 4RSP.pdb, b) 2GX4.pdb, c) 7C8T.pdb, d) with blue, black or green dashed line with arrow at H bond acceptor.

Fig. 4

Binding site characteristics of hyphobicity, aromaticity and H bonding for the proteins, a–c: 4RSP.pdb, d–f: 2GX4.pdb, g–i:7C8T.pdb.