Pathogenesis, Symptomatology, and Transmission of SARS-CoV-2 through Analysis of Viral Genomics and Structure

Abstract

COVID-19 involves a number of organ systems and can present with a wide range of symptoms. From how the virus infects cells to how it spreads between people, the available research suggests that these patterns are very similar to those seen in the closely related viruses SARS-CoV-1 and possibly Middle East respiratory syndrome-related CoV (MERS-CoV).

Healthy Immunity on Preventive Medicine for Combating COVID-19

“…It is noteworthy that a large number of COVID-19 patients recover from viral infections due to their healthy immunity. As such, children and adolescents, possessing healthy immunity, generally exhibit mild symptoms, including fever, headache, fatigue, and nasal congestion [ 12 , 72 ]. Conversely, a subset of patients, with impaired immunity and/or underlying medical conditions, display severe clinical manifestations, requiring hospitalizations and life-supporting treatments, with fatal outcomes [ 73 ].…”

“…Notably, COVID-19 genomic variants, i.e., α, β, γ, δ, and Omicron (most contagious), have shown significant effects in different parts of the world and are responsible for the majority of COVID-19-associated infections and complications. Mechanistically, the spike protein is composed of two functional subunits, S1 and S2; the former binds to ACE2, and S2 is responsible for viral fusion [ 12 , 74 ]. The binding of the S2 subunit allows for insertion of the RNA genome into the host cells, which then undergoes proteolytic cleavages by host proteases (e.g., furin and trypsin) and translation to form polyproteins that are then assembled to make replication-transcription complexes.…”

“…The binding of the S2 subunit allows for insertion of the RNA genome into the host cells, which then undergoes proteolytic cleavages by host proteases (e.g., furin and trypsin) and translation to form polyproteins that are then assembled to make replication-transcription complexes. Once the complex is formed (a copy of the RNA genome), structural proteins are synthesized in the cytoplasm and assembled with help from the endoplasmic reticulum and Golgi apparatus [ 12 , 74 , 75 ]. The viral particles are then released from the cell by exocytosis and have the ability to infect other cells and continue the replication process.…”

“…Of note, COVID-19 displays similar clinical features to those of SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome) that have been previously reported [ 10 ]. Airborne transmission is the primary mode of infection for the spread of the COVID-19 virus that enters host cells upon binding to the angiotensin converting enzyme 2 (ACE2) receptors [ 11 , 12 ]. The pathophysiological manifestations of this disease include fever, headache, respiratory distress, hypoxia, lung injury, inflammation, and cardiovascular diseases (CVDs).…”

Considerations for the Safe Operation of Schools During the Coronavirus Pandemic

“…While the age dependency of infection risk is controversial, there is strong evidence that children who are infected with SARS-CoV-2 have a substantially lower risk of severe outcomes than adults. Most are diagnosed with asymptomatic or minimally symptomatic infections ( 36 – 41 ) or experience a mild form of respiratory disease that will typically resolve within a week or two ( 25 , 42 – 46 ). Increasing evidence suggests that the airway epithelium of children may have a better ability to sense infection with SARS-CoV-2 and may mount a more pronounced immune response than adults, resulting in faster viral clearance ( 47 – 49 ).…”