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Sex-specific disparities in COVID-19 outcomes
Rafique, Z., Durkalski-Mauldin, V., Peacock, W. F., Yadav, K., Reynolds, J. C., Callaway, C. W.
Journal of the American College of Emergency Physicians open. 2024;5(1):e13110
Abstract
OBJECTIVES Sex-specific disparities in morbidity and mortality of COVID-19 illness are not well understood. Neutralizing antibodies (Ab) may protect against severe COVID-19 illness. We investigated the association of sex with disease progression and SARS-CoV-2 Ab response. METHODS In this exploratory analysis of the phase 3, multicenter, randomized, placebo-controlled Convalescent Plasma in Outpatients (C3PO) trial, we examined whether sex was associated with progression to severe illness, defined as a composite of all-cause hospitalization, emergency/urgent care visit, or death within 15 days from study enrollment. Patients had a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test, symptom onset within 7 days, stable condition for emergency department discharge, and were either ≥50 years old or had at least one high-risk feature for disease progression. Patients received blinded convalescent plasma or placebo in a 1:1 fashion and were evaluated on days 15 and 30 after infusion. Blood samples were collected on day 0 (pre-/post-infusion), 15, and 30 to measure Ab levels with the Broad Institute using the Plaque Reduction Neutralization Test assay. RESULTS Of 511 patients enrolled (median age 54 [Iinterquartile range 41-62] years, 46% male, 66% white, 20% black, 3.5% Asian), disease progression occurred in 36.7% of males and 25.9% of females (unadjusted risk difference 10.8%, 95% confidence interval [CI], 2.8-18.8%). Sex-disparities did not persist when adjusted for treatment group, age, viremic status, symptom onset, and tobacco use (adjusted risk difference 5.6%, 95% confidence interval [CI], -2.2% to 13.4%), but were present in the subgroup presenting 3 or more days after symptom onset (adjusted risk difference 12.6%, 95% CI, 3.4% to 21.9%). Mean baseline Ab levels (log scale) available for 367 patients were similar between sexes (difference 0.19 log units, 95% CI, -0.08 to 0.46). The log-scale mean increase from baseline to day 15 after adjusting for treatment assignment and baseline levels was larger in males than females (3.26 vs. 2.67). A similar difference was noted when the groups were subdivided by outcome. CONCLUSIONS Progression of COVID-19 was similar in males and females when adjusted for age, tobacco use, and viremia status in this study. However, in the cohort presenting 3 or more days after symptom onset, COVID-19 outcomes were worse in males than females. Neutralizing Ab levels increased more in males but did not correlate with sex differences in outcomes.
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COVID-19 Convalescent Plasma Therapy: Long-term Implications
Yoon, H., Li, Y., Goldfeld, K. S., Cobb, G. F., Sturm-Reganato, C. L., Ostrosky-Zeichner, L., Jayaweera, D. T., Philley, J. V., Desruisseaux, M. S., Keller, M. J., et al
Open forum infectious diseases. 2024;11(1):ofad686
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Abstract
BACKGROUND The long-term effect of coronavirus disease 2019 (COVID-19) acute treatments on postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) is unknown. The CONTAIN-Extend study explores the long-term impact of COVID-19 convalescent plasma (CCP) therapy on postacute sequelae of SARS-CoV-2 infection (PASC) symptoms and general health 18 months following hospitalization. METHODS The CONTAIN-Extend study examined 281 participants from the original CONTAIN COVID-19 trial (CONTAIN-RCT, NCT04364737) at 18 months post-hospitalization for acute COVID-19. Symptom surveys, global health assessments, and biospecimen collection were performed from November 2021 to October 2022. Multivariable logistic and linear regression estimated associations between the randomization arms and self-reported symptoms and Patient-Reported Outcomes Measurement Information System (PROMIS) scores and adjusted for covariables, including age, sex, race/ethnicity, disease severity, and CONTAIN enrollment quarter and sites. RESULTS There were no differences in symptoms or PROMIS scores between CCP and placebo (adjusted odds ratio [aOR] of general symptoms, 0.95; 95% CI, 0.54-1.67). However, females (aOR, 3.01; 95% CI, 1.73-5.34), those 45-64 years (aOR, 2.55; 95% CI, 1.14-6.23), and April-June 2020 enrollees (aOR, 2.39; 95% CI, 1.10-5.19) were more likely to report general symptoms and have poorer PROMIS physical health scores than their respective reference groups. Hispanic participants (difference, -3.05; 95% CI, -5.82 to -0.27) and Black participants (-4.48; 95% CI, -7.94 to -1.02) had poorer PROMIS physical health than White participants. CONCLUSIONS CCP demonstrated no lasting effect on PASC symptoms or overall health in comparison to the placebo. This study underscores the significance of demographic factors, including sex, age, and timing of acute infection, in influencing symptom reporting 18 months after acute hypoxic COVID-19 hospitalization.
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COVID-19 Convalescent Plasma Outpatient Therapy to Prevent Outpatient Hospitalization: A Meta-analysis of Individual Participant Data From Five Randomized Trials
Levine AC, Fukuta Y, Huaman MA, Ou J, Meisenberg BR, Patel B, Paxton JH, Hanley DF, Rijnders BJ, Gharbharan A, et al
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2023
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Editor's Choice
Abstract
BACKGROUND Outpatient monoclonal antibodies are no longer effective and antiviral treatments for COVID-19 disease remain largely unavailable in many countries worldwide. Although treatment with COVID-19 convalescent plasma is promising, clinical trials among outpatients have shown mixed results. METHODS We conducted an individual participant data meta-analysis from outpatient trials to assess the overall risk reduction for all-cause hospitalizations by day 28 in transfused participants. Relevant trials were identified by searching MEDLINE, Embase, MedRxiv, World Health Organization, Cochrane Library, and Web of Science from January 2020 to September 2022. RESULTS Five included studies from four countries enrolled and transfused 2,620 adult patients. Comorbidities were present in 1,795 (69%). The virus neutralizing antibody dilutional titer levels ranged from 8 to 14,580 in diverse assays. 160 (12.2%) of 1315 control patients were hospitalized, versus 111 (8.5%) of 1305 COVID-19 convalescent plasma treated patients, yielding a 3.7% (95%CI: 1.3%-6.0%; p=.001) absolute risk reduction and 30.1% relative risk reduction for all-cause hospitalization. The hospitalization reduction was greatest in those with both early transfusion and high titer with a 7.6% absolute risk reduction (95%CI: 4.0%-11.1%; p=.0001) accompanied by at 51.4% relative risk reduction. No significant reduction in hospitalization was seen with treatment > 5 days after symptom onset or in those receiving COVID-19 convalescent plasma with antibody titers below the median titer. CONCLUSIONS Among outpatients with COVID-19, treatment with COVID-19 convalescent plasma reduced the rate of all-cause hospitalization and may be most effective when given within 5 days of symptom onset and when antibody titer is higher.
PICO Summary
Population
Adult COVID-19 outpatients (5 studies, n= 2,620).
Intervention
Intravenous COVID-19 convalescent plasma (CCP) transfusion (n= 1,305).
Comparison
Non-convalescent plasma or normal saline (n= 1,315).
Outcome
The virus neutralizing antibody dilutional titre levels ranged from 8 to 14,580 in diverse assays. 160 (12.2%) of 1,315 control patients were hospitalized, versus 111 (8.5%) of 1,305 COVID-19 convalescent plasma treated patients, yielding a 3.7% (95% CI: 1.3% - 6.0%) absolute risk reduction and 30.1% relative risk reduction for all-cause hospitalization. The hospitalization reduction was greatest in those with both early transfusion and high titre with a 7.6% absolute risk reduction (95% CI: 4.0% - 11.1%) accompanied by at 51.4% relative risk reduction. No significant reduction in hospitalization was seen with treatment > 5 days after symptom onset or in those receiving COVID-19 convalescent plasma with antibody titres below the median titre.
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Symptom duration and resolution with early outpatient treatment of convalescent plasma for COVID- 19: a randomized trial
Baksh S, Heath SL, Fukuta Y, Shade D, Meisenberg B, Bloch EM, Tobian AAR, Spivak ES, Patel B, Gerber J, et al
The Journal of infectious diseases. 2023
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Abstract
BACKGROUND COVID-19 convalescent plasma (CCP) reduces hospitalizations among outpatients treated early after symptom onset. It is unknown if CCP reduces time to symptom resolution among outpatients. METHODS We evaluated symptom resolution at day 14 by trial arm using an adjusted sub-distribution hazard model, with hospitalization as a competing risk. Additionally, we assessed prevalence of symptom clusters at day 14 between treatments. Clusters were defined based on biologic clustering, impact on ability to work, and an algorithm. RESULTS Among 1,070 outpatients followed after transfusion, 381 of 538 (70.8%) receiving CCP and 381 of 532 (71.6%) receiving control plasma were still symptomatic (p = 0.78) at day 14. Associations between CCP and symptom resolution by day 14 were not statistically different from those in controls after adjusting for baseline characteristics (adjusted sub-distribution hazard ratio: 0.99; p = 0.62). The most common cluster consisted of cough, fatigue, shortness of breath, and headache, found in 308 (57.2%) and 325 (61.1%) of CCP and control plasma recipients, respectively (p = 0.16). CONCLUSIONS In this trial of outpatients with early COVID-19, CCP was not associated with faster resolution of symptoms compared to control. Overall, there were no differences in the prevalence of each symptom or symptom clusters at day 14 by treatment.
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Efficacy of combined COVID-19 convalescent plasma with oral RNA-dependent RNA polymerase inhibitor treatment versus neutralizing monoclonal antibody therapy in COVID-19 outpatients: a multi-center, non-inferiority, open-label randomized controlled trial (PlasMab)
Siripongboonsitti, T., Nontawong, N., Tawinprai, K., Suptawiwat, O., Soonklang, K., Poovorawan, Y., Mahanonda, N.
Microbiology spectrum. 2023;:e0325723
Abstract
This pivotal study reveals that high neutralizing titer COVID-19 convalescent plasma therapy (CPT) combined with favipiravir (FPV) is non-inferior to sotrovimab in preventing hospitalization and severe outcomes in outpatients with mild-to-moderate COVID-19 and high-risk comorbidities. It underscores the potential of CPT-FPV as a viable alternative to neutralizing monoclonal antibodies like sotrovimab, especially amid emerging variants with spike protein mutations. The study's unique approach, comparing a monoclonal antibody with CPT, demonstrates the efficacy of early intervention using high neutralizing antibody titer CPT, even in populations with a significant proportion of elderly patients. These findings are crucial, considering the alternative treatment challenges, especially in resource-limited countries, posed by the rapidly mutating SARS-CoV-2 virus and the need for adaptable therapeutic strategies.
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Use of covid-19 convalescent plasma to treat patients admitted to hospital for covid-19 with or without underlying immunodeficiency: open label, randomised clinical trial
Lacombe, K., Hueso, T., Porcher, R., Mekinian, A., Chiarabini, T., Georgin-Lavialle, S., Ader, F., Saison, J., Martin-Blondel, G., De Castro, N., et al
BMJ medicine. 2023;2(1):e000427
Abstract
OBJECTIVE To evaluate the efficacy of covid-19 convalescent plasma to treat patients admitted to hospital for moderate covid-19 disease with or without underlying immunodeficiency (CORIPLASM trial). DESIGN Open label, randomised clinical trial. SETTING CORIMUNO-19 cohort (publicly supported platform of open label, randomised controlled trials of immune modulatory drugs in patients admitted to hospital with moderate or severe covid-19 disease) based on 19 university and general hospitals across France, from 16 April 2020 to 21 April 2021. PARTICIPANTS 120 adults (n=60 in the covid-19 convalescent plasma group, n=60 in the usual care group) admitted to hospital with a positive SARS-CoV2 test result, duration of symptoms <9 days, and World Health Organization score of 4 or 5. 49 patients (n=22, n=27) had underlying immunosuppression. INTERVENTIONS Open label randomisation to usual care or four units (200-220 mL/unit, 2 units/day over two consecutive days) of covid-19 convalescent plasma with a seroneutralisation titre >40. MAIN OUTCOME MEASURES Primary outcomes were proportion of patients with a WHO Clinical Progression Scale score of ≥6 on the 10 point scale on day 4 (higher values indicate a worse outcome), and survival without assisted ventilation or additional immunomodulatory treatment by day 14. Secondary outcomes were changes in WHO Clinical Progression Scale scores, overall survival, time to discharge, and time to end of dependence on oxygen supply. Predefined subgroups analyses included immunosuppression status, duration of symptoms before randomisation, and use of steroids. RESULTS 120 patients were recruited and assigned to covid-19 convalescent plasma (n=60) or usual care (n=60), including 22 (covid-19 convalescent plasma) and 27 (usual care) patients who were immunocompromised. 13 (22%) patients who received convalescent plasma had a WHO Clinical Progression Scale score of ≥6 at day 4 versus eight (13%) patients who received usual care (adjusted odds ratio 1.88, 95% credible interval 0.71 to 5.24). By day 14, 19 (31.6%) patients in the convalescent plasma group and 20 (33.3%) patients in the usual care group needed ventilation, additional immunomodulatory treatment, or had died. For cumulative incidence of death, three (5%) patients in the convalescent plasma group and eight (13%) in the usual care group died by day 14 (adjusted hazard ratio 0.40, 95% confidence interval 0.10 to 1.53), and seven (12%) patients in the convalescent plasma group and 12 (20%) in the usual care group by day 28 (adjusted hazard ratio 0.51, 0.20 to 1.32). In a subgroup analysis performed in patients who were immunocompromised, transfusion of covid-19 convalescent plasma was associated with mortality (hazard ratio 0.39, 95% confidence interval 0.14 to 1.10). CONCLUSIONS In this study, covid-19 convalescent plasma did not improve early outcomes in patients with moderate covid-19 disease. The efficacy of convalescent plasma in patients who are immunocompromised should be investigated further. TRIAL REGISTRATION ClinicalTrials.gov NCT04345991.
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Early antibody treatment, inflammation, and risk of post-COVID conditions
Gebo, K. A., Heath, S. L., Fukuta, Y., Zhu, X., Baksh, S., Abraham, A. G., Habtehyimer, F., Shade, D., Ruff, J., Ram, M., et al
mBio. 2023;:e0061823
Abstract
Post-COVID conditions (PCCs) are common and have significant morbidity. Risk factors for PCC include advancing age, female sex, obesity, and diabetes mellitus. Little is known about treatment, inflammation, and PCC. Among 882 individuals with confirmed SARS-CoV-2 infection participating in a randomized trial of COVID-19 convalescent plasma (CCP) vs control plasma with available biospecimens and symptom data, the association between early CCP treatment, cytokine levels, and PCC was evaluated. Cytokine and chemokine levels were assessed at baseline, day 14, and day 90 using a multiplexed sandwich immunoassay (Meso Scale Discovery). Presence of any self-reported PCC symptoms was assessed at day 90. Associations between CCP treatment, cytokine levels, and PCC were examined using multivariate logistic regression models. One third of the 882 participants had day 90 PCC symptoms, with fatigue (14.5%) and anosmia (14.5%) being most common. Cytokine levels decreased from baseline to day 90. In a multivariable analysis, female sex (adjusted odds ratio [AOR] = 2.69 [1.93-3.81]), older age (AOR = 1.32 [1.17-1.50]), and elevated baseline levels of IL-6 (AOR = 1.59 [1.02-2.47]) were independently associated with development of PCC. Those who received early CCP treatment (≤5 days after symptom onset) compared to late CCP treatment had statistically significant lower odds of PCC. IMPORTANCE Approximately 20% of individuals infected with SARS-CoV-2 experienced long-term health effects, as defined PCC. However, it is unknown if there are any early biomarkers associated with PCC or whether early intervention treatments may decrease the risk of PCC. In a secondary analysis of a randomized clinical trial, this study demonstrates that among outpatients with SARS-CoV-2, increased IL-6 at time of infection is associated with increased odds of PCC. In addition, among individuals treated early, within 5 days of symptom onset, with COVID-19 convalescent plasma, there was a trend for decreased odds of PCC after adjusting for other demographic and clinical characteristics. Future treatment studies should be considered to evaluate the effect of early treatment and anti-IL-6 therapies on PCC development.
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Convalescent Plasma for Covid-19-Induced ARDS in Mechanically Ventilated Patients
Misset, B., Piagnerelli, M., Hoste, E., Dardenne, N., Grimaldi, D., Michaux, I., De Waele, E., Dumoulin, A., Jorens, P. G., van der Hauwaert, E., et al
The New England journal of medicine. 2023;389(17):1590-1600
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Editor's Choice
Abstract
BACKGROUND Passive immunization with plasma collected from convalescent patients has been regularly used to treat coronavirus disease 2019 (Covid-19). Minimal data are available regarding the use of convalescent plasma in patients with Covid-19-induced acute respiratory distress syndrome (ARDS). METHODS In this open-label trial, we randomly assigned adult patients with Covid-19-induced ARDS who had been receiving invasive mechanical ventilation for less than 5 days in a 1:1 ratio to receive either convalescent plasma with a neutralizing antibody titer of at least 1:320 or standard care alone. Randomization was stratified according to the time from tracheal intubation to inclusion. The primary outcome was death by day 28. RESULTS A total of 475 patients underwent randomization from September 2020 through March 2022. Overall, 237 patients were assigned to receive convalescent plasma and 238 to receive standard care. Owing to a shortage of convalescent plasma, a neutralizing antibody titer of 1:160 was administered to 17.7% of the patients in the convalescent-plasma group. Glucocorticoids were administered to 466 patients (98.1%). At day 28, mortality was 35.4% in the convalescent-plasma group and 45.0% in the standard-care group (P = 0.03). In a prespecified analysis, this effect was observed mainly in patients who underwent randomization 48 hours or less after the initiation of invasive mechanical ventilation. Serious adverse events did not differ substantially between the two groups. CONCLUSIONS The administration of plasma collected from convalescent donors with a neutralizing antibody titer of at least 1:160 to patients with Covid-19-induced ARDS within 5 days after the initiation of invasive mechanical ventilation significantly reduced mortality at day 28. This effect was mainly observed in patients who underwent randomization 48 hours or less after ventilation initiation. (Funded by the Belgian Health Care Knowledge Center; ClinicalTrials.gov number, NCT04558476.).
PICO Summary
Population
Adult patients with Covid-19-induced acute respiratory distress syndrome (n= 475).
Intervention
Convalescent plasma (n= 237).
Comparison
Standard care (n= 238).
Outcome
At day 28, mortality was 35.4% in the convalescent-plasma group and 45.0% in the standard-care group. In a prespecified analysis, this effect was observed mainly in patients who underwent randomization 48 hours or less after the initiation of invasive mechanical ventilation. Serious adverse events did not differ substantially between the two groups.
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The efficacy and safety of remdesivir alone and in combination with other drugs for the treatment of COVID-19: a systematic review and meta-analysis
Chen, C., Fang, J., Chen, S., Rajaofera, M. J. N., Li, X., Wang, B., Xia, Q.
BMC infectious diseases. 2023;23(1):672
Abstract
BACKGROUND Remdesivir is considered to be a specific drug for treating coronavirus disease 2019. This systematic review aims to evaluate the clinical efficacy and risk of remdesivir alone and in combination with other drugs. RESEARCH DESIGN AND METHODS The PubMed, Embase, SCIE, Cochrane Library, and American Clinical trial Center databases were searched up to 1 April 2022 to identify. Randomized controlled trials (RCTs) and observational studies comparing the efficacy of remdesivir monotherapy and combination therapy with that of control drugs. RESULTS Ten RCTs and 32 observational studies were included in the analysis. Regarding the primary outcome, remdesivir use reduced mortality in patients with severe COVID-19 (RR = 0.57, 95% CI (0.48,0.68)) and shortened the time to clinical improvement (MD = -2.51, 95% CI (-2.75, -2.28)). Regarding other clinical outcomes, remdesivir use was associated with improved clinical status (RR = 1.08, 95%CI (1.01, 1.17)). Regarding safety outcomes, remdesivir use did not cause liver or kidney damage (RR = 0.87, 95%CI (0.68, 1.11)) (RR = 0.88, 95%CI (0.70,1.10)). Compared with remdesivir alone, remdesivir combined with other drugs (e.g., steroids, favipiravir, and convalescent plasma) had no effect on mortality. CONCLUSION The use of remdesivir can help to reduce the mortality of patients with severe COVID-19 and shorten the time to clinical improvement. There was no benefit of remdesivir combination therapy for other clinical outcomes. TRIAL REGISTRATION PROSPERO registration number: CRD42022322859.
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Convalescent plasma for people with COVID-19: a living systematic review
Iannizzi C, Chai KL, Piechotta V, Valk SJ, Kimber C, Monsef I, Wood EM, Lamikanra AA, Roberts DJ, McQuilten Z, et al
The Cochrane database of systematic reviews. 2023;2(2):Cd013600
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Editor's Choice
Abstract
BACKGROUND Convalescent plasma may reduce mortality in patients with viral respiratory diseases, and is being investigated as a potential therapy for coronavirus disease 2019 (COVID-19). A thorough understanding of the current body of evidence regarding benefits and risks of this intervention is required. OBJECTIVES To assess the effectiveness and safety of convalescent plasma transfusion in the treatment of people with COVID-19; and to maintain the currency of the evidence using a living systematic review approach. SEARCH METHODS To identify completed and ongoing studies, we searched the World Health Organization (WHO) COVID-19 Global literature on coronavirus disease Research Database, MEDLINE, Embase, Cochrane COVID-19 Study Register, and the Epistemonikos COVID-19 L*OVE Platform. We searched monthly until 03 March 2022. SELECTION CRITERIA We included randomised controlled trials (RCTs) evaluating convalescent plasma for COVID-19, irrespective of disease severity, age, gender or ethnicity. We excluded studies that included populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS)), as well as studies evaluating standard immunoglobulin. DATA COLLECTION AND ANALYSIS We followed standard Cochrane methodology. To assess bias in included studies we used RoB 2. We used the GRADE approach to rate the certainty of evidence for the following outcomes: all-cause mortality at up to day 28, worsening and improvement of clinical status (for individuals with moderate to severe disease), hospital admission or death, COVID-19 symptoms resolution (for individuals with mild disease), quality of life, grade 3 or 4 adverse events, and serious adverse events. MAIN RESULTS In this fourth review update version, we included 33 RCTs with 24,861 participants, of whom 11,432 received convalescent plasma. Of these, nine studies are single-centre studies and 24 are multi-centre studies. Fourteen studies took place in America, eight in Europe, three in South-East Asia, two in Africa, two in western Pacific and three in eastern Mediterranean regions and one in multiple regions. We identified a further 49 ongoing studies evaluating convalescent plasma, and 33 studies reporting as being completed. Individuals with a confirmed diagnosis of COVID-19 and moderate to severe disease 29 RCTs investigated the use of convalescent plasma for 22,728 participants with moderate to severe disease. 23 RCTs with 22,020 participants compared convalescent plasma to placebo or standard care alone, five compared to standard plasma and one compared to human immunoglobulin. We evaluate subgroups on detection of antibodies detection, symptom onset, country income groups and several co-morbidities in the full text. Convalescent plasma versus placebo or standard care alone Convalescent plasma does not reduce all-cause mortality at up to day 28 (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.92 to 1.03; 220 per 1000; 21 RCTs, 19,021 participants; high-certainty evidence). It has little to no impact on need for invasive mechanical ventilation, or death (RR 1.03, 95% CI 0.97 to 1.11; 296 per 1000; 6 RCTs, 14,477 participants; high-certainty evidence) and has no impact on whether participants are discharged from hospital (RR 1.00, 95% CI 0.97 to 1.02; 665 per 1000; 6 RCTs, 12,721 participants; high-certainty evidence). Convalescent plasma may have little to no impact on quality of life (MD 1.00, 95% CI -2.14 to 4.14; 1 RCT, 483 participants; low-certainty evidence). Convalescent plasma may have little to no impact on the risk of grades 3 and 4 adverse events (RR 1.17, 95% CI 0.96 to 1.42; 212 per 1000; 6 RCTs, 2392 participants; low-certainty evidence). It has probably little to no effect on the risk of serious adverse events (RR 1.14, 95% CI 0.91 to 1.44; 135 per 1000; 6 RCTs, 3901 participants; moderate-certainty evidence). Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces or increases all-cause mortality at up to day 28 (RR 0.73, 95% CI 0.45 to 1.19; 129 per 1000; 4 RCTs, 484 participants; very low-certainty evidence). We are uncertain whether convalescent plasma reduces or increases the need for invasive mechanical ventilation, or death (RR 5.59, 95% CI 0.29 to 108.38; 311 per 1000; 1 study, 34 participants; very low-certainty evidence) and whether it reduces or increases the risk of serious adverse events (RR 0.80, 95% CI 0.55 to 1.15; 236 per 1000; 3 RCTs, 327 participants; very low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus human immunoglobulin Convalescent plasma may have little to no effect on all-cause mortality at up to day 28 (RR 1.07, 95% CI 0.76 to 1.50; 464 per 1000; 1 study, 190 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Individuals with a confirmed diagnosis of SARS-CoV-2 infection and mild disease We identified two RCTs reporting on 536 participants, comparing convalescent plasma to placebo or standard care alone, and two RCTs reporting on 1597 participants with mild disease, comparing convalescent plasma to standard plasma. Convalescent plasma versus placebo or standard care alone We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (odds ratio (OR) 0.36, 95% CI 0.09 to 1.46; 8 per 1000; 2 RCTs, 536 participants; very low-certainty evidence). It may have little to no effect on admission to hospital or death within 28 days (RR 1.05, 95% CI 0.60 to 1.84; 117 per 1000; 1 RCT, 376 participants; low-certainty evidence), on time to COVID-19 symptom resolution (hazard ratio (HR) 1.05, 95% CI 0.85 to 1.30; 483 per 1000; 1 RCT, 376 participants; low-certainty evidence), on the risk of grades 3 and 4 adverse events (RR 1.29, 95% CI 0.75 to 2.19; 144 per 1000; 1 RCT, 376 participants; low-certainty evidence) and the risk of serious adverse events (RR 1.14, 95% CI 0.66 to 1.94; 133 per 1000; 1 RCT, 376 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. Convalescent plasma versus standard plasma We are uncertain whether convalescent plasma reduces all-cause mortality at up to day 28 (OR 0.30, 95% CI 0.05 to 1.75; 2 per 1000; 2 RCTs, 1597 participants; very low-certainty evidence). It probably reduces admission to hospital or death within 28 days (RR 0.49, 95% CI 0.31 to 0.75; 36 per 1000; 2 RCTs, 1595 participants; moderate-certainty evidence). Convalescent plasma may have little to no effect on initial symptom resolution at up to day 28 (RR 1.12, 95% CI 0.98 to 1.27; 1 RCT, 416 participants; low-certainty evidence). We did not identify any study reporting other key outcomes. This is a living systematic review. We search monthly for new evidence and update the review when we identify relevant new evidence. AUTHORS' CONCLUSIONS For the comparison of convalescent plasma versus placebo or standard care alone, our certainty in the evidence that convalescent plasma for individuals with moderate to severe disease does not reduce mortality and has little to no impact on clinical improvement or worsening is high. It probably has little to no effect on SAEs. For individuals with mild disease, we have low certainty evidence for our primary outcomes. There are 49 ongoing studies, and 33 studies reported as complete in a trials registry. Publication of ongoing studies might resolve some of the uncertainties around convalescent plasma therapy for people with asymptomatic or mild disease.
PICO Summary
Population
People of any age with mild, moderate or severe COVID-19 (33 randomised controlled trials, n= 24,861).
Intervention
Convalescent plasma (n= 11,432).
Comparison
Standard plasma, human immunoglobulin, placebo or standard care alone.
Outcome
This living systematic review was a fourth review update version and included 33 studies. The authors identified 49 ongoing studies. For the comparison of convalescent plasma versus placebo or standard care alone, the authors’ certainty in the evidence that convalescent plasma for individuals with moderate to severe disease does not reduce mortality and has little to no impact on clinical improvement or worsening is high. For individuals with mild disease, the authors have low certainty evidence for the primary outcomes.