Shedding Lights on the Extracellular Vesicles as Functional Mediator and Therapeutic Decoy for COVID-19

COVID-19 is an infectious disease caused by the novel coronavirus (SARS-CoV-2) that first appeared in late 2019 and has since spread across the world. It is characterized by symptoms such as fever, cough, and shortness of breath and can lead to death in severe cases. To help contain the virus, measures such as social distancing, handwashing, and other public health measures have been implemented. Vaccine and drug candidates, such as those developed by Pfizer/BioNTech, AstraZeneca, Moderna, Novavax, and Johnson & Johnson, have been developed and are being distributed worldwide. Clinical trials for drug treatments such as remdesivir, dexamethasone, and monoclonal antibodies are underway and have shown promising results. Recently, exosomes have gained attention as a possible mediator of the COVID-19 infection. Exosomes, small vesicles with a size of around 30–200 nm, released from cells, contain viral particles and other molecules that can activate the immune system and/or facilitate viral entry into target cells. Apparently, the role of exosomes in eliciting various immune responses and causing tissue injury in COVID-19 pathogenesis has been discussed. In addition, the potential of exosomes as theranostic and therapeutic agents for the treatment of COVID-19 has been elaborated.