Background: COVID-19-related pneumonia was initially rare, though influenza-related pneumonia is well known as a severe complication of influenza. However, COVID-19-related pneumonia may be increasing since the omicron variant of COVID-19 appeared. Methods: The clinical differences between COVID-19-related and influenza-related pneumonia patients were retrospectively investigated in patients hospitalized from January 2022 to December 2023. Results: COVID-19-related and influenza-related pneumonias were found in 46 of 285 (15.8%) and 6 of 12 (50.0%) patients, respectively (p<0.001). Their mean ages were 75.5 (45-93) years and 53.8 (19-73) years in COVID-19-related and influenza-related pneumonia cases, respectively (p=0.002). Aspiration pneumonia was more common in COVID-19-related pneumonia (28/46=60.9%) than in influenza-related pneumonia patients, and it was treated by sulbactam/ampicillin (31/46=67.4%). The influenza-related pneumonia patients were more often infected in the work place (2/6=33.3%) and not vaccinated (4/6=66.7%), compared with COVID-19-related patients. Death occurred in 7 of 46 (15.2%) COVID-19 patients, but none of 6 influenza-infected patients died. Conclusions: These data suggest that COVID-19-related pneumonia presented as aspiration pneumonia in older patients, although influenza-related pneumonia was more common in younger and non-vaccinated patients and might be associated with immune mechanisms during the omicron variant surge era.

Coronaviruses (CoVs) are a broad family of potentially serious RNA viruses that are now causing an outbreak of respiratory disease known as CoV disease 2019 (COVID-19). Melatonin is a pineal hormone that is predominantly produced and released at night from the amino acid tryptophan. Melatonin and its metabolites are also important in immunomodulation, and they have antioxidative properties due to their capacity to scavenge reactive oxygen species both directly and indirectly. COVID-19 leads to changes of altered consciousness levels in about 15% of hospitalized patients, starting from somnolence to disorientation, delirium, stupor, and coma. Melatonin can decrease the molecules that cause delirium in the elderly and central respiratory depression, such as benzodiazepines and antipsychotics. Melatonin may help alleviate infection-induced acute respiratory distress as well as its diverse effects, which include anti-inflammatory, antioxidative, and immune-enhancing properties. Its supplemental dose may be able to prevent SARS-COV-2 infections by reversing aerobic glycolysis via suppression of both HIF-1 and mTOR, allowing pyruvate dehydrogenase complex activity to be suppressed and acetyl-coenzyme A to be produced. When mitochondrion-produced and parenteral melatonin are combined, the cytokine storm is reduced, and COVID-19 infection-induced damage is alleviated. In conclusion, melatonin could have an important role in the management of COVID-19.

CoV-2 disease 2019 (COVID-19) pandemic has exerted a great burden on the health and economic systems worldwide. One of the most important factors that affect the severity and prognosis of COVID-19 is the occurrence of hyperstimulation of the immune system resulting in “cytokine storm”. Similar to SARS-CoV, an intracellular complex called nod like receptor family pyrin domain containing 3 (NLRP3) inflammasome was found to be activated by SARS-CoV-2, then in turn stimulates several interleukins and initiates the inflammatory cascade. In addition, other inflammatory mediators such as interferons e.g., IFN-α, and IFN-γ, interleukins e.g., IL-1β, IL-12, IL-18, tumor necrosis factor-α (TNF- α), and chemokines e.g., CCL2, CXCL10 have been reported in severely ill patients. These mediators represent the corner stone in developing cytokine storm that results in uncontrolled systemic inflammatory reaction with subsequent acute respiratory distress syndrome (ARDS), multiple organ failure and eventually death. Based on its anti-inflammatory effects, colchicine has also gained attention to be utilized in the management of COVID-19 patient. Colchicine exerts its anti-inflammatory effect through inhibition of formation of microtubules which is considered an essential step in several cellular processes such as division, signalling, and migration. Also, colchicine affects the cytokine cascade by inhibiting IL-1β leading to reduction in neutrophils recruitment, free radicles production and inflammasome stimulation. This raises the concerns about the effectiveness of colchicine in COVID-19 treatment and the possibility of providing an improvement of the clinical course of the disease.