Employment of old options to control novel coronavirus: Pros and Cons

Abstract

Since late December 2019, humans have been under danger due to an outbreak of a coronavirus (SARS-CoV-2) disease COVID-19. Worldwide uncontrolled occurrences (16,812,755 cases out of which 662,095 died as on 30th July 2020) of COVID-19, challenge to public health infrastructures and becoming a grave threat to the population. The condition is becoming worse as the disease is transmitting through a vast number of asymptomatic and pre-symptomatic cases. While the World is finding expedited approvals for the development of a vaccine, which is time-dependent, being preventative and not possibly a cure, physicians are considering several age-old immunotherapeutic techniques– the Convalescent plasma (CP) therapy and antimalarial drug, hydroxychloroquine (HCQ) could be therapeutic options against COVID-19 infection. CP therapy involves the use of passive immunization where the administration of antibodies from a given donor to a susceptible person to initiate the development of immunity to the recipient against SARS-COV-2 is initiated. For the CP therapy to be effective, an adequate amount of antibody has to be administered to the recipient from the donor at the very early stages of the COVID-19 disease. CP therapy for COVID-19 may be beneficial for prophylactic as well as for treatment purposes. But, people may experience any inadvertent untoward effects including immunological reactions and blood-borne pathogenic infections related to blood transfusion. Furthermore, the use of CP therapy may cause antibody-dependent enhancement (ADE) or immune enhancement as a result of infectivity and virulence of the pathogen. As employment of the ADE mechanism may be one of the reasons behind the high severity of SARS-CoV-2 among the older population. On the other hand, HCQ has diverse modes of action, like alteration of the acidic environment inside lysosome, late endosomes, restriction further with endocytosis, exosome release, phagolysosomal fusion in systematically and subsequently inhibition of cytokine storm in the host cell. But, a study report from Brazil warns that the high-dose group patients had more severe QT prolongation (syndrome of heart rhythm disorder, causes arrhythmias) and tendency near higher lethality compared to the low dose. At the time of their reporting, the overall fatality rate across both arms of the study was 13.5%. They are indicating that the percentage of fatality rate was overlapping with the patients, not taking HCQ. One of the sums of diverse mechanisms might work against viral infections and help prevent more deaths. Overall, in this situation of unavailability of specific medication, the CP therapy and HCQ treatment might act as an immediate saviour for society from the pandemic.