Convalescent plasma for COVID19
Convalescent plasma has been used as a therapy for several viral infections in the recent past, including EBOLA, SARS-CoV, H5N1 avian influenza, and H1N1.
Albert Yan, MD commentary:
In the article by Shen et al (JAMA: March 27, 2020), 5 patients had severe COVID19 receiving artificial ventilation and high viral load. Of these 5 patients, all had been treated with methylprednisolone, with 4 of the 5 having received lopinavir/ritonavir, 3 having received interferon alfa-1b, and 2 having received favipiravir. Given the severity of their illness, they were administered convalescent plasma obtained from donors between 18-60 years of age who had already recovered from SARS-COV2 and been asymptomatic for at least 10 days. The donors all tested negative for COVID19 and other respiratory viruses as well as bloodborne illnesses (HBV, HCV, HIV, syphilis). They had to have documented SARS-CoV2-specific antibody titers of greater than 1:1000 and a neutralizing antibody of greater than 40. Donors then received 400 mL of convalescent plasma on the same day it was donated to maximize the activity of the product. In all 5 patients, inflammatory markers showed significant improvement following the single infusion, pulmonary findings on CT scans showed improvement. Of the 5 patients who were mechanically ventilated, 3 were successfully weaned within 5 days and then discharged within 11-13 days later. The two remaining patients showed stabilization, and the patient who was on ECMO was decannulated successfully within 5 days. These are promising results and show that convalescent plasma warrants further investigation, especially given its past success with other similar viral illnesses. At present, many questions remain unanswered, including the overall efficacy and safety in larger study populations, optimal timing of the intervention, whether more frequent dosing regimens might work better, and whether coordination with other antiviral therapies might provide even greater benefits, and whether such a treatment could be scaled up to address the mounting number of cases being seen should this treatment prove effective.