Infectious disease immunotherapies - An update: Revisiting an age-old adage in times of COVID-19

This review article tries to bring together the important active and passive immunotherapeutic modalities currently under consideration for COVID-19 disease. The basis of immunotherapy is based on use of naturally occurring agents or drugs to modify the body's immune response to certain antigens, the host immune system competent to successfully target and eliminate the infectious agent, without altering the normal physiology. Pubmed was screened for studies using key words; COVID-19, Convalescent plasma therapy, Immunotherapy, Clinical trials. We identified 537 studies through database searches. After reviewing the title and abstracts, we excluded 452 studies that were not relevant, leaving 85 studies for full-text evaluation. Of these, 53 studies fulfilling predefined inclusion/exclusion criteria were finally included. This study found that the common immunotherapies which were used in COVID-19 pandemic times were plasma therapy, T-reg based therapy, tocilizumab, hydroxychloroquine, dexamethasone, and baricitinib.