Abstract: RESEARCH Anup Agarwal,1 Aparna Mukherjee,1 Gunjan Kumar,1 Pranab Chatterjee,1 Tarun Bhatnagar,2 Pankaj Malhotra,3 on behalf of the PLACID Trial Collaborators 1 Clinical Trial and Health Systems Research Unit, Indian Council of Medical Research, V Ramalingaswamy Bhawan, PO Box 4911, Ansari Nagar, New Delhi, 110029, India 2 ICMR School of Public Health, Indian Council of Medical Research -National Institute of Epidemiology, Chennai, Tamil, India 3 Department of Internal Medicine, Post Graduate Institute of Medical Education and Research, Chandigarh, India Correspondence to: A Mukherjee, Clinical Trial and Health Systems Research Unit, Indian Council of Medical Research, V Ramalingaswamy Bhawan, PO Box 4911, Ansari Nagar, New Delhi, 110029, India aparna.sinha.deb@icmr.gov.in (ORCID 0000-0001-7298-5097) Additional material is published online only. To view please visit the journal online. Cite this as: BMJ 2020;371:m3939 http://dx.doi.org/10.1136/bmj.m3939 Accepted: 12 October 2020 ABSTRACT OBJECTIVE To investigate the effectiveness of using convalescent plasma to treat moderate coronavirus disease 2019 (covid-19) in adults in India. DESIGN Open label, parallel arm, phase II, multicentre, randomised controlled trial. SETTING 39 public and private hospitals across India. PARTICIPANTS 464 adults (≥18 years) admitted to hospital (screened 22 April to 14 July 2020) with confirmed moderate covid-19 (partial pressure of oxygen in arterial blood/ fraction of inspired oxygen (PaO2/FiO2) ratio between 200 mm Hg and 300 mm Hg or a respiratory rate of more than 24/min with oxygen saturation 93% or less on room air): 235 were assigned to convalescent plasma with best standard of care (intervention arm) and 229 to best standard of care only (control arm). INTERVENTIONS Participants in the intervention arm received two doses of 200 mL convalescent plasma, transfused 24 hours apart. The presence and levels of neutralising antibodies were not measured a priori; stored samples were assayed at the end of the study. MAIN OUTCOME MEASURE Composite of progression to severe disease (PaO2/ FiO2 <100 mm Hg) or all cause mortality at 28 days post-enrolment. WHAT IS ALREADY KNOWN ON THIS TOPIC As of October 2020, multiple small case series, one large observational study (>35 000 patients), and three randomised trials have been published on the utility of convalescent plasma to treat coronavirus disease 2019 (covid-19) Although the observational studies suggested clinical benefits in recipients of convalescent plasma, the trials were stopped early and failed to ascertain any mortality benefit from convalescent plasma treatment in patients with covid-19 WHAT THIS STUDY ADDS In settings with limited laboratory capacity, convalescent plasma does not reduce 28 day mortality or progression to severe disease in patients admitted to hospital with moderate covid-19 Convalescent plasma treatment was associated with earlier resolution of shortness of breath and fatigue and higher negative conversion of SARS-CoV-2 RNA on day 7 of enrolment As a potential treatment for patients with moderate covid-19, convalescent plasma showed limited effectiveness the bmj | BMJ 2020;371:m3939 | doi: 10.1136/bmj.m3939 RESULTS Progression to severe disease or all cause mortality at 28 days after enrolment occurred in 44 (19%) participants in the intervention arm and 41 (18%) in the control arm (risk difference 0.008 (95% confidence interval −0.062 to 0.078); risk ratio 1.04, 95%..