Recent findings on the Coronavirus disease 2019 (COVID-19); immunopathogenesis and immunotherapeutics

Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) is responsible for recent ongoing public health
emergency in the world. Sharing structural and behavioral similarities with its ancestors [SARS and Middle East
Respiratory Syndrome (MERS)], SARS-CoV-2 has lower fatality but faster transmission. We have gone through a
long path to recognize SARS and MERS, therefore our knowledge regarding SARS-CoV-2 is not raw. Various
responses of the immune system account for the wide spectrum of clinical manifestations in Coronavirus disease-
2019 (COVID-19). Given the innate immune response as the front line of defense, it is immediately activated
after the virus entry. Consequently, adaptive immune response is activated to eradicate the virus. However, this
does not occur in every case and immune response is the main culprit causing the pathological manifestations of
COVID-19. Lethal forms of the disease are correlated with inefficient and/or insufficient immune responses
associated with cytokine storm. Current therapeutic approach for COVID-19 is in favor of suppressing extreme
inflammatory responses, while maintaining the immune system alert and responsive against the virus. This could
be contributing along with administration of antiviral drugs in such patients. Furthermore, supplementation
with different compounds, such as vitamin D, has been tested to modulate the immune system responses. A
thorough understanding of chronological events in COVID-19 contributing to the development of a highly efficient
treatment has not figured out yet. This review focuses on the virus-immune system interaction as well as
currently available and potential therapeutic approaches targeting immune system in the treatment of COVID-19
patients