The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection. This pandemic is an enormous threat to global economic and health security. Some infected individuals are asymptomatic, while others develop acute respiratory distress syndrome and severe life-threatening viral pneumonia. Although individual risk factors contribute to disease severity (e.g., increasing age, male sex, and higher body mass index), these risk factors cannot explain all the variability in disease severity observed between individuals.

In addition, many factors may affect these individual differences. Scientists have also raised the possibility that genetic variation for the viral S protein receptor and ACE2 (angiotensin-converting enzyme 2) in human cells may lead to male and worsening clinical outcomes in some regions. Furthermore, the scientists also discovered that lipoproteins element E (ApoE) gene variation might increase the risk of COVID-19 infection and acute and severe illness.