Pneumonia brought on by the 2019 coronavirus disease (COVID-19) outbreak is extremely dangerous. Researchers anticipate that convalescent plasma therapy (CPT) will successfully treat passive immunity against COVID-19. The benefits of CPT in severe, early-onset cases of COVID-19 require proof of a high titer of neutralizing antibodies. This case-control study compared conventional treatment with a transfusion of high-titer (≥ 1:320) COVID-19 convalescent plasma for severe COVID-19 pneumonia.

Among 107 severe COVID-19 patients, 55 received CPT plus standard care, while 52 received standard care alone. The CPT group had a death rate of 15.3%, while the conventional care group had a mortality rate of 85.4% (P<0.001). CPT was associated with a lower risk of death in both univariate and multivariate models (hazard ratio [HR] 0.14; 95% CI 0.07-0.31; P<0.001 and HR 0.26; 95% CI 0.08-0.79; P=0.018, respectively). The need for high-flow oxygen, the duration of mechanical ventilation, and the need for supplemental oxygen all decreased once CPT was implemented. Both the radiological and clinical results got better.

Immediate CPT in patients with a high neutralizing antibody titer is well tolerated and decreases mortality in those with severe COVID-19 who develop the disease early. However, additional research is needed to determine whether or not CPT is beneficial during the early stages of a disease.