Geetanjeli R and Sheogobind MPA*

Assistant Professor, Howard University College of Dentistry, Department of Restorative Dentistry, USA

*Corresponding Author: Sheogobind MPA, Assistant Professor, Howard University College of Dentistry, Department of Restorative Dentistry, USA.

Received: May 13, 2025; Published: May 20, 2025

Abstract

The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has presented unprecedented challenges to global health, scientific communities, and healthcare infrastructure. This handbook provides a concise yet comprehensive review of the virus's biology, clinical manifestations, epidemiology, and the global response, with emphasis on the molecular structure and pathogenesis of SARS-CoV-2. It examines the role of virulence factors, the clinical spectrum of COVID-19 symptoms, the impact of pre-existing conditions such as hypertension on disease severity, and evaluates the efficacy of therapeutic strategies including antiviral agents, corticosteroids, and vaccination.
Additionally, the handbook contextualizes the human toll of the pandemic with an analysis of worldwide mortality data from 2020 through 2022, offering insights into excess mortality trends. The work is supported by rigorously selected peer-reviewed literature and it is intended to contribute to clinical understanding, inform future preparedness, and highlight the vital intersections of virology, public health, and clinical medicine in pandemic response.

Keywords: “SARS-CoV-2 Virology; COVID-19 Symptoms; COVID-19 Pathogenesis; Preexisting Conditions for Infection with SARS-CoV-2 Virus

References

1. Zhu N., et al. “A novel coronavirus from patients with pneumonia in China, 2019”. The New England Journal of Medicine 8 (2020): 727-733.
2. Kim D., et al. “The architecture of SARS-CoV-2 transcriptome”. Cell 181.4 (2020): 914-921.e10.
3. Wu A., et al. “Genome composition and divergence of the novel coronavirus (2019-nCoV) originating in China”. Cell Host Microbe 27.3 (2020): 325-328.
4. Hoffmann M., et al. “SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor”. Cell 181.2 (2020): 271-280.e8.
5. Walls AC., et al. “Structure, function, and antigenicity of the SARS-CoV-2 spike glycoprotein”. Cell 181.2 (2020): 281-292.e6.
6. V’kovski P., et al. “Coronavirus biology and replication: implications for SARS-CoV-2”. Nature Reviews Microbiology 19.3 (2021): 155-170.
7. Snijder EJ., et al. “A unifying structural and functional model of the coronavirus replication organelle: tracking down RNA synthesis”. PLoS Biology 18.6 (2020): e3000715.
8. Bradley BT., et al. “Histopathology and ultrastructural findings of fatal COVID-19 infections in Washington State: a case series”. Lancet 396.10247 (2020): 320-332.
9. Hamming I., et al. “Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis”. Journal of Pathology 203.2 (2004): 631-637.
10. Shang J., et al. “Cell entry mechanisms of SARS-CoV-2”. Proceedings of the National Academy of Sciences of the United States of America 117.21 (2020): 11727-11734.
11. Coutard B., et al. “The spike glycoprotein of the new coronavirus 2019-nCoV contains a furin-like cleavage site absent in CoV of the same clade”. Antiviral Research 176 (2020): 104742.
12. Blanco-Melo D., et al. “Imbalanced host response to SARS-CoV-2 drives development of COVID-19”. Cell 181.5 (2020): 1036-1045.e9.
13. Miorin L., et al. “SARS-CoV-2 ORF6 hijacks Nup98 to block STAT nuclear import and antagonize interferon signaling. Proceedings of the National Academy of Sciences of the United States of America 117.45 (2020): 28344-28354.
14. Moore JB, June CH. Cytokine release syndrome in severe COVID-19”. Science 368.6490 (2020): 473-474.
15. Ackermann M., et al. “Pulmonary vascular endothelialitis, thrombosis, and angiogenesis in COVID-19”. The New England Journal of Medicine 383.2 (2020): 120-128.
16. Zhang S., et al. “SARS-CoV-2 binds platelet ACE2 to enhance thrombosis in COVID-19”. Journal of Hematology and Oncology 13.1 (2020): 120.
17. Meng B., et al. “Altered TMPRSS2 usage by SARS-CoV-2 Omicron impacts infectivity and fusogenicity”. Nature 603.7902 (2022): 706-714.
18. Lauer SA., et al. “The incubation period of coronavirus disease 2019 (COVID-19) from publicly reported confirmed cases: estimation and application”. Annals of Internal Medicine 172.9 (2020): 577-582.
19. Guan WJ., et al. “Clinical characteristics of coronavirus disease 2019 in China”. The New England Journal of Medicine 382.18 (2020): 1708-1720.
20. Lechien JR., et al. “Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter European study”. European Archives of Oto-Rhino-Laryngology 277.8 (2020): 2251-2261.
21. Yan CH., et al. “Association of chemosensory dysfunction and COVID-19 in patients presenting with influenza-like symptoms”. International Forum of Allergy and Rhinology 10.7 (2020): 806-813.
22. Pan L., et al. “Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study”. The American Journal of Gastroenterology 115.5 (2020): 766-773.
23. Xiao F., et al. “Evidence for gastrointestinal infection of SARS-CoV-2”. Gastroenterology 158.6 (2020): 1831-1833.e3.
24. Huang C., et al. “Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China”. Lancet 395.10223 (2020): 497-506.
25. Mao L., et al. “Neurologic manifestations of hospitalized patients with coronavirus disease 2019 in Wuhan, China”. JAMA Neurology 77.6 (2020): 683-690.
26. Richardson S., et al. “Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area”. JAMA 323.20 (2020): 2052-2059.
27. Zhou F., et al. “Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study”. Lancet 395.10229 (2020): 1054-1062.
28. Gheblawi M., et al. “Angiotensin-converting enzyme 2: SARS-CoV-2 receptor and regulator of the renin-angiotensin system”. Circulation Research 126.10 (2020): 1456-1474.
29. Fang L., et al. “Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection?” The Lancet Respiratory Medicine 8.4 (2020): e21.
30. Reynolds HR., et al. “Renin-angiotensin-aldosterone system inhibitors and risk of COVID-19”. The New England Journal of Medicine 382.25 (2020): 2441-2448.
31. Verdecchia P., et al. “The pivotal link between ACE2 deficiency and SARS-CoV-2 infection”. European Journal of Internal Medicine 76 (2020): 14-20.
32. Varga Z., et al. “Endothelial cell infection and endotheliitis in COVID-19”. Lancet 395.10234 (2020): 1417-1418.
33. Chen R., et al. “Risk factors of fatal outcome in hospitalized subjects with coronavirus disease 2019 from a nationwide analysis in China”. Chest 158.1 (2020): 97-105.
34. Richardson S., et al. “Presenting characteristics, comorbidities, and outcomes among 5700 patients hospitalized with COVID-19 in the New York City area”. JAMA 323.20 (2020): 2052-2059.
35. Vaduganathan M., et al. “Renin-angiotensin-aldosterone system inhibitors in patients with COVID-19”. The New England Journal of Medicine 382.17 (2020): 1653-1659.
36. Beigel JH., et al. “Remdesivir for the treatment of COVID-19-final report”. The New England Journal of Medicine 383.19 (2020): 1813-1826.
37. Hammond J., et al. “Oral nirmatrelvir for high-risk, nonhospitalized adults with COVID-19”. The New England Journal of Medicine 386.15 (2022): 1397-1408.
38. Jayk Bernal A., et al. “Molnupiravir for oral treatment of COVID-19 in nonhospitalized patients”. The New England Journal of Medicine 386.6 (2022): 509-520.
39. The RECOVERY Collaborative Group. Dexamethasone in hospitalized patients with COVID-19”. The New England Journal of Medicine 384.8 (2021): 693-704.
40. The REMAP-CAP Investigators. Interleukin-6 receptor antagonists in critically ill patients with COVID-19”. The New England Journal of Medicine 384.16 (2021): 1491-1502.
41. Marconi VC., et al. “Efficacy and safety of baricitinib for the treatment of hospitalized adults with COVID-19”. The Lancet Respiratory Medicine 9.12 (2021): 1407-1418.
42. Spyropoulos AC., et al. “Scientific and standardization committee communication: clinical guidance on thrombosis and hemostasis issues in critically ill patients with COVID-19”. Journal of Thrombosis and Haemostasis 18.8 (2020): 1859-1865.
43. Planas D., et al. “Considerable escape of SARS-CoV-2 Omicron to antibody neutralization”. Nature 602.7898 (2022): 671-675.
44. Simonovich VA., et al. “A randomized trial of convalescent plasma in COVID-19 severe pneumonia”. The New England Journal of Medicine 384.7 (2021): 619-629.
45. Fan E., et al. “COVID-19-associated acute respiratory distress syndrome: is a different approach to management warranted?” The Lancet Respiratory Medicine 8.8 (2020): 816-821.
46. Barbaro RP., et al. “Extracorporeal membrane oxygenation support in COVID-19: an international cohort study of the Extracorporeal Life Support Organization registry”. Lancet 396.10257 (2020): 1071-1078.
47. World Health Organization. WHO Coronavirus (COVID-19) Dashboard”. Geneva: WHO (2022).
48. Johns Hopkins University. “COVID-19 Dashboard by the Center for Systems Science and Engineering”. Baltimore: JHU (2020).
49. Grasselli G., et al. “Baseline characteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lombardy region, Italy”. JAMA 323.16 (2020): 1574-1581.
50. Micochova P., et al. “SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion”. Nature 599.7883 (2021): 114-119.
51. Mathieu E., et al. “A global database of COVID-19 vaccinations”. Nature Human Behaviour 5.7 (2021): 947-953.
52. Nyberg T., et al. “Comparative analysis of the risks of hospitalisation and death associated with SARS-CoV-2 Omicron (B.1.1.529) and Delta (B.1.617.2) variants in England”. Lancet10332 (2022): 1303-1312.
53. Stokes AC., et al. “Excess deaths during the COVID-19 pandemic: historical trend analysis of 29 high-income countries”. BMJ 373 (2021): n1137.
54. Wang H., et al. “Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21”. Lancet  399.10334 (2022): 1513-1536.
55. Karlinsky A and Kobak D. “Tracking excess mortality across countries during the COVID-19 pandemic with the World Mortality Dataset”. eLife 10 (2021): e69336.
56. Harvey WT., et al. “SARS-CoV-2 variants, spike mutations and immune escape”. Nature Reviews Microbiology 19.7 (2021): 409-424.
57. Wu Z and McGoogan JM. “Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: summary of a report of 72,314 cases from the Chinese Center for Disease Control and Prevention”. JAMA 323.13 (2020): 1239-1242.
58. Zhou F., et al. “Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study”. Lancet 395.10229 (2020): 1054-1062.
59. Polack FP., et al. “Safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine”. The New England Journal of Medicine 383.27 (2020): 2603-2615.
60. Moghadas SM., et al. “The impact of vaccination on COVID-19 outbreaks in the United States”. Clinical Infectious Diseases 73.12 (2021): 2257-2264.
61. RECOVERY Collaborative Group. Dexamethasone in hospitalized patients with Covid-19”. The New England Journal of Medicine 384.8 (2021): 693-704.
62. Hammond J., et al. “Oral nirmatrelvir for high-risk, nonhospitalized adults with Covid-19”. The New England Journal of Medicine 386.15 (2022):1397-1408.
63. Wang H., et al. “Estimating excess mortality due to the COVID-19 pandemic: a systematic analysis of COVID-19-related mortality, 2020-21”. Lancet 399.10334 (2022): 1513-1536.
64. Nalbandian A., et al. “Post-acute COVID-19 syndrome”. Nature Medicine 27.4 (2021): 601-615.

Citation

Citation: Geetanjeli R and Sheogobind MPA. “SARS-CoV-2 (COVID-19) Handbook for Medical and Dental Professionals".Acta Scientific Microbiology 8.6 (2025): 42-52.

Copyright

Copyright: © 2025 Geetanjeli R and Sheogobind MPA. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.