COVID-19: immune response and therapeutic perspective

Disease caused by the new coronavirus (COVID-19) is characterized by fever, cough, and affection of the lower respiratory tract. It is associated with age, comorbidities and a weakened immune system. Typically, lymphopenias have been evidenced in severe cases and an excessive production of inflammatory cytokines (cytokine storm), which would explain the role of the hyperinflammatory response in the pathogenesis of COVID-19. Secondary inflammatory responses from virus reinfections may induce antibody-dependent enhancement (ADE), a viremic phenomenon that may be an alternative mechanism of cellular infection and should be considered when designing vaccines or immunotherapies involving the stimulation of neutralizing antibodies or the use of monoclonal antibodies. Currently, no vaccines or treatments demonstrate safety and efficacy in patients with COVID-19. However, the results from phase III clinical trials which involve the application of an mRNA (messenger ribonucleic acid) nucleic acid vaccine and an antiviral drug (remdisivir), are yet to be concluded. For the time being, the best measure to prevent the spread of COVID-19 is by implementing social isolation, this measure has been adopted by several countries as recommended by the World Health Organization (WHO).