From Emergence to Endemicity: A Comprehensive Review of COVID-19

Abstract

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later renamed coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in early December 2019. Initially, the China office of the World Health Organization was informed of numerous cases of pneumonia of unidentified etiology in Wuhan, Hubei Province at the end of 2019. This would subsequently result in a global pandemic with millions of confirmed cases of COVID-19 and millions of deaths reported to the WHO. We have analyzed most of the data published since the beginning of the pandemic to compile this comprehensive review of SARS-CoV-2. We looked at the core ideas, such as the etiology, epidemiology, pathogenesis, clinical symptoms, diagnostics, histopathologic findings, consequences, therapies, and vaccines. We have also included the long-term effects and myths associated with some therapeutics of COVID-19. This study presents a comprehensive assessment of the SARS-CoV-2 virology, vaccines, medicines, and significant variants identified during the course of the pandemic. Our review article is intended to provide medical practitioners with a better understanding of the fundamental sciences, clinical treatment, and prevention of COVID-19. As of May 2023, this paper contains the most recent data made accessible.

Keywords: covid-19; emergence; endemicity; sars-cov-2; vaccine; variants; virus.

Figure 1. Timeline of detection of coronaviruses

CoV: coronavirus; SARS: severe acute respiratory syndrome, MERS: Middle East respiratory syndrome

Figure 2. Timeline of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern

Figure 3. Structure of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

M-protein: membrane protein; RNA: ribonucleic acid; N-protein: nucleocapsid protein; E-protein: envelope protein Image Source: Scientific Animations (CC BY-SA 4.0)

Figure 4. Different phases of coronavirus disease 2019 (COVID-19) progression

ARDS: Acute respiratory distress syndrome Image Source: Marik et al., 2021 [77]; Open Access CC BY-NC 4.0 Deed

Figure 5. Histological changes from COVID-19 in lungs. (A) Alveolar injury with desquamation and hyaline membrane formation (arrow); (B) No evidence of inflammatory cellular infiltration; (C) Interstitial thickening; (D) Intra-alveolar hemorrhages (asterisk) and the presence of fibrin plugs; (E) Interstitial thickening due to AT2 cell hyperplasia and alveolar infiltration by inflammatory cells with fibrinoid necrosis noted; (F) Intra-alveolar infiltration with neutrophils suggestive of bacterial superinfection

COVID-19: coronavirus disease 2019; AT2: alveolar type 2 Image Source: Tian et al., 2020 [86]; Open Access

Figure 6. Organ system manifestations of COVID-19

SIADH: syndrome of inappropriate anti-diuretic hormone secretion; IgA: immunoglobulin A; ARDS: acute respiratory distress syndrome; COVID-19: coronavirus disease 2019

Figure 7. List of various types of COVID-19 trials

Covid: coronavirus disease, ECMO: extra-corporeal membrane oxygenation; COVID-19: coronavirus disease 2019

Figure 8. . Medications used to date in the treatment of coronavirus disease 2019 (COVID-19) infection.

GM-CSF: granulocyte-macrophage colony-stimulating factor

Figure 9. Different types of vaccine platforms

DNA: deoxyribonucleic acid; RNA: ribonucleic acid; SARS-CoV-2: severe acute respiratory syndrome-coronavirus-2 Image Source: COVID-19 Vaccine Tracker (https://covid19.trackvaccines.org/vaccine-types/)