Early experience with convalescent #plasma as immunotherapy for #COVID‐19 in China: Knowns and unknowns

In the absence of a vaccine or specific drug treatment options for coronavirus disease (COVID‐19), attention has been shifted in China to the possible therapeutic use of convalescent plasma. COVID‐19 convalescent plasma (CCP) is currently under investigation. We summarized clinical studies and other research data available as of 5 May 2020 on CCP therapy according to the Clinical Treatment Guideline of COVID‐19 Convalescent Plasma in China, as well as clinical experience at the First Affiliated Hospital of Zhejiang University, as part of a comprehensive anti‐epidemic strategy.

Materials and methods
As of 5 May 2020, when the epidemic was well‐controlled in China, healthcare databases and sources of English literature relating to convalescent plasma were searched and reviewed. Sources of clinical and methodological heterogeneity were identified.

As of 5 May 2020, up to 2000 samples of CCP had been collected across China and administered to 700 COVID‐19 patients. From donors, 200–400 ml of plasma was collected at each donation, with antibody titres > 1:160. We identified three clinical studies for COVID‐19 in China. Analyses showed a statistically significant improvement in clinical outcomes compared with untreated cases (P < 0.001). No adverse effects were reported.

From initial studies, convalescent plasma therapy appears effective and safe for COVID‐19. However, there is clearly a need for well‐designed RCTs (randomized controlled trials) or other formal studies to further evaluate the efficacy and any potential adverse effects of CCP.