Tixagevimab-cilgavimab (AZD7442) for the treatment of patients hospitalized with COVID-19 (DisCoVeRy): A phase 3, randomized, double-blind, placebo-controlled trial (preprint)

Background Tixagevimab and cilgavimab (AZD7442) are two monoclonal antibodies developed by AstraZeneca for the pre-exposure prophylaxis and treatment of patients infected by SARS-CoV-2. Its effectiveness and safety in patients hospitalized with COVID-19 was not known at the outset of this trial. Methods DisCoVeRy is a phase 3, adaptive, multicentre, randomized, controlled trial conducted in 63 sites in Europe. Participants were randomly assigned (1:1) to receive placebo or tixagevimab-cilgavimab in addition to standard of care. The primary outcome was the clinical status at day 15 measured by the WHO seven-point ordinal scale. Several clinical, virological, immunological and safety endpoints were also assessed. Findings Due to slow enrolment, recruitment was stopped on July 1st, 2022. The antigen positive modified intention-to-treat population (mITT) was composed of 173 participants randomized to tixagevimab-cilgavimab (n=91) or placebo (n=82), 91.9% (159/173) with supplementary oxygen, and 47.4% (82/173) previously vaccinated at inclusion. There was no significant difference in the distribution of the WHO ordinal scale at day 15 between the two groups (odds ratio (OR) 0.93, 95%CI [0.54-1.61]; p=0.81) nor in any clinical, virological or safety secondary endpoints. In the global mITT (n=226), neutralization antibody titers were significantly higher in the tixagevimab-cilgavimab group/patients compared to placebo at day 3 (Least-square mean differences (LSMD) 1.44, 95% Confidence interval (CI) [1.20-1.68]; p < 10-23) and day 8 (LSMD 0.91, 95%CI [0.64-1.18]; p < 10-8) and it was most important for patients infected with a pre-omicron variant, both at day 3 (LSMD 1.94, 95% CI [1.67-2.20], p < 10-25) and day 8 (LSMD 1.17, 95% CI [0.87-1.47], p < 10-9), with a significant interaction (p < 10-7 and p=0.01 at days 3 and 8, respectively). Interpretation There were no significant differences between tixagevimab-cilgavimab and placebo in clinical endpoints, however the trial lacked power compared to prespecified calculations. Tixagevimab-cilgavimab was well tolerated, with low rates of treatment related events.

Lack of association between HLA and asymptomatic SARS-CoV-2 infection (preprint)

Human genetic studies of critical COVID-19 pneumonia have revealed the essential role of type I interferon-dependent innate immunity to SARS-CoV-2 infection. Conversely, an association between the HLA-B*15:01 allele and asymptomatic SARS-CoV-2 infection in unvaccinated individuals was recently reported, suggesting a contribution of pre-existing T cell-dependent adaptive immunity. We report a lack of association of classical HLA alleles, including HLA-B*15:01, with pre-omicron asymptomatic SARS-CoV-2 infection in unvaccinated participants in a prospective population-based study in the US (191 asymptomatic vs. 945 symptomatic COVID-19 cases). Moreover, we found no such association in the international COVID Human Genetic Effort cohort (206 asymptomatic vs. 574 mild or moderate COVID-19 cases and 1,625 severe or critical COVID-19 cases). Finally, in the Human Challenge Characterisation study, the three HLA-B*15:01 individuals infected with SARS-CoV-2 developed symptoms. As with other acute primary infections, no classical HLA alleles favoring an asymptomatic course of SARS-CoV-2 infection were identified. These findings suggest that memory T-cell immunity to seasonal coronaviruses does not strongly influence the outcome of SARS-CoV-2 infection in unvaccinated individuals.

Could faecal viral excretion explain gastrointestinal symptoms in COVID-19 patients: co- infection involvement? (preprint)

Objectives: Physiopathological mechanisms responsible for digestive symptoms during COVID-19 are still unclear. The aim of this study was to determine the influence of faecal viral shedding on digestive symptoms and propose differential diagnoses to better understand the gastrointestinal clinical spectrum during acute COVID-19.Methods: Patients were included if one stool sample was available for microbiological investigation. Microbiological analysis consisted of syndromic PCR screening, and parasitological investigation included microsporidia and multiplex protozoa PCR. SARS-CoV-2 infection was diagnosed by viral detection (on respiratory samples and frozen stool samples) and by serology when necessary. Collected epidemiological, clinical, radiological, biological data and clinical course were compared according to COVID-19 status, faecal SARS-CoV-2 shedding and co-infection status.Results: 50 COVID+ and 67 COVID- patients were included. Faecal viral shedding was detected in 50% of stool samples and was associated with higher viral load in the upper respiratory tract. There was no difference in the proportion of detected enteric pathogens between COVID-19 status. No impact was observed on clinical course regardless of COVID-19 status, faecal SARS-CoV-2 shedding and coinfection status.Conclusions: SARS-CoV-2 shedding and enteric pathogen involvement in gastrointestinal presentation is still unclear. However, differential diagnostic investigation revealed frequently occurring common enteric pathogens in COVID-19 patients.

Remdesivir for the treatment of hospitalised patients with COVID-19: final results from the DisCoVeRy randomised, controlled, open-label trial (preprint)

Background: The antiviral efficacy of remdesivir is still controversial. We aimed at evaluating its clinical effectiveness in hospitalised patients with COVID-19, with indication of oxygen and/or ventilator support. Following prior publication of preliminary results, here we present the final results after completion of data monitoring. Methods: In this European multicentre, open-label, parallel-group, randomised, controlled trial (DisCoVeRy, NCT04315948, EudraCT2020-000936-23), participants were randomly allocated to receive usual standard of care (SoC) alone or in combination with remdesivir, lopinavir/ritonavir, lopinavir/ritonavir and IFN-beta-1a, or hydroxychloroquine. Adult patients hospitalised with COVID-19 were eligible if they had clinical evidence of hypoxemic pneumonia, or required oxygen supplementation. Exclusion criteria included elevated liver enzyme, severe chronic kidney disease, any contra-indication to one of the studied treatments or their use in the 29 days before randomization, or use of ribavirin, as well as pregnancy or breast-feeding. Here, we report results for remdesivir + SoC versus SoC alone. Remdesivir was administered as 200 mg infusion on day 1, followed by once daily infusions of 100 mg up to 9 days, for a total duration of 10 days. It could be stopped after 5 days if the participant was discharged. Treatment assignation was performed via web-based block randomisation stratified on illness severity and administrative European region. The primary outcome was the clinical status at day 15 measured by the WHO 7-point ordinal scale, assessed in the intention-to-treat population. Findings: Between March 22nd, 2020 and January 21st, 2021, 857 participants were randomised to one of the two arms in 5 European countries and 843 participants were included for the evaluation of remdesivir (control, n=423; remdesivir, n=420). At day 15, the distribution of the WHO ordinal scale was as follow in the remdesivir and control groups, respectively: Not hospitalized, no limitations on activities: 62/420 (14.8%) and 72/423 (17.0%); Not hospitalized, limitation on activities: 126/420 (30%) and 135/423 (31.9%); Hospitalized, not requiring supplemental oxygen: 56/420 (13.3%) and 31/423 (7.3%); Hospitalized, requiring supplemental oxygen: 75/420 (17.9%) and 65/423 (15.4%); Hospitalized, on non-invasive ventilation or high flow oxygen devices: 16/420 (3.8%) and 16/423 (3.8%); Hospitalized, on invasive mechanical ventilation or ECMO: 64/420 (15.2%) and 80/423 (18.9%); Death: 21/420 (5%) and 24/423 (5.7%). The difference between treatment groups was not statistically significant (OR for remdesivir, 1.02, 95% CI, 0.62 to 1.70, P=0.93). There was no significant difference in the occurrence of Serious Adverse Events between treatment groups (remdesivir, n=147/410, 35.9%, versus control, n=138/423, 32.6%, p=0.29). Interpretation: Remdesivir use for the treatment of hospitalised patients with COVID-19 was not associated with clinical improvement at day 15. Funding: European Union Commission, French Ministry of Health, DIM One Health Ile-de-France, REACTing, Fonds Erasme-COVID-ULB; Belgian Health Care Knowledge Centre (KCE), AGMT gGmbH, FEDER "European Regional Development Fund", Portugal Ministry of Health, Portugal Agency for Clinical Research and Biomedical Innovation. Remdesivir was provided free of charge by Gilead.

An open-label randomized, controlled trial of the effect of lopinavir/ritonavir, lopinavir/ritonavir plus IFN-β-1a and hydroxychloroquine in hospitalized patients with COVID-19 – Final results from the DisCoVeRy trial (preprint)

Objectives We evaluated the clinical, virological and safety outcomes of lopinavir/ritonavir, lopinavir/ritonavir-interferon (IFN)-β-1a, hydroxychloroquine or remdesivir in comparison to standard of care (control) in COVID-19 inpatients requiring oxygen and/or ventilatory support. While preliminary results were previously published, we present here the final results, following completion of the data monitoring. Methods We conducted a phase 3 multi-centre open-label, randomized 1:1:1:1:1, adaptive, controlled trial (DisCoVeRy), add-on trial to Solidarity ( NCT04315948 , EudraCT2020-000936-23). The primary outcome was the clinical status at day 15, measured by the WHO 7-point ordinal scale. Secondary outcomes included SARS-CoV-2 quantification in respiratory specimens, pharmacokinetic and safety analyses. We report the results for the lopinavir/ritonavir-containing arms and for the hydroxychloroquine arm, which were stopped prematurely. Results The intention-to-treat population included 593 participants (lopinavir/ritonavir, n=147; lopinavir/ritonavir-IFN-β-1a, n=147; hydroxychloroquine, n=150; control, n=149), among whom 421 (71.0%) were male, the median age was 64 years (IQR, 54-71) and 214 (36.1%) had a severe disease. The day 15 clinical status was not improved with investigational treatments: lopinavir/ritonavir versus control, adjusted odds ratio (aOR) 0.82, (95% confidence interval [CI] 0.54-1.25, P=0.36); lopinavir/ritonavir-IFN-β-1a versus control, aOR 0.69 (95%CI 0.45-1.05, P=0.08); hydroxychloroquine versus control, aOR 0.94 (95%CI 0.62-1.41, P=0.76). No significant effect of investigational treatment was observed on SARS-CoV-2 clearance. Trough plasma concentrations of lopinavir and ritonavir were higher than those expected, while those of hydroxychloroquine were those expected with the dosing regimen. The occurrence of Serious Adverse Events was significantly higher in participants allocated to the lopinavir/ritonavir-containing arms. Conclusion In adults hospitalized for COVID-19, lopinavir/ritonavir, lopinavir/ritonavir-IFN-ß-1a and hydroxychloroquine did not improve the clinical status at day 15, nor SARS-CoV-2 clearance in respiratory tract specimens.

The risk of COVID-19 death is much greater and age-dependent with type I IFN autoantibodies (preprint)

SARS-CoV-2 infection fatality rate (IFR) doubles with every five years of age from childhood onward. Circulating autoantibodies neutralizing IFN-α, IFN-ω, and/or IFN-β are found in ~20% of deceased patients across age groups. In the general population, they are found in ~1% of individuals aged 20-70 years and in >4% of those >70 years old. With a sample of 1,261 deceased patients and 34,159 uninfected individuals, we estimated both IFR and relative risk of death (RRD) across age groups for individuals carrying autoantibodies neutralizing type I IFNs, relative to non-carriers. For autoantibodies neutralizing IFN-α2 or IFN-ω, the RRD was 17.0[95% CI:11.7-24.7] for individuals under 70 years old and 5.8[4.5-7.4] for individuals aged 70 and over, whereas, for autoantibodies neutralizing both molecules, the RRD was 188.3[44.8-774.4] and 7.2[5.0-10.3], respectively. IFRs increased with age, from 0.17%[0.12-0.31] for individuals <40 years old to 26.7%[20.3-35.2] for those ≥80 years old for autoantibodies neutralizing IFN-α2 or IFN-ω, and from 0.84%[0.31-8.28] to 40.5%[27.82-61.20] for the same two age groups, for autoantibodies neutralizing both molecules. Autoantibodies against type I IFNs increase IFRs, and are associated with high RRDs, particularly those neutralizing both IFN-α2 and -ω. Remarkably, IFR increases with age, whereas RRD decreases with age. Autoimmunity to type I IFNs appears to be second only to age among common predictors of COVID-19 death.

Modeling remdesivir antiviral efficacy in COVID-19 hospitalized patients of the randomized, controlled, open-label DisCoVeRy trial (preprint)

Despite several clinical studies, the antiviral efficacy of remdesivir in COVID-19 hospitalized patients remains controversial. We analyzed nasopharyngeal normalized viral loads collected in the 29 days following randomization from 665 hospitalized patients included in the DisCoVeRy trial, allocated to either standard of care (SoC, N=329) or SoC + remdesivir for 10 days (N=336). We used a mathematical model to reconstruct viral kinetic profiles and estimate the antiviral efficacy of remdesivir in reducing viral production. To identify factors associated with viral kinetics, additional analyses were conducted stratified either on time of treatment initiation ([≤] or > 7 days since symptom onset) or viral load at randomization (< or [≥] 3.5 log10 copies/104 cells). In our model, remdesivir reduced viral production by 2-fold on average (95%CI: 1.5-3.2). Using the estimated parameter of the model, simulations predict that remdesivir reduces time to viral clearance by 0.7 day compared to SoC, with large inter-individual variabilities (Inter-Quartile Range, IQR: 0.0-1.3 days). Exploratory analyses suggest that remdesivir had a larger impact in patients with a high viral load at randomization, reducing viral production by 5-fold on average (95%CI: 2.8-25), leading to a predicted median reduction in the time to viral clearance of 2.4 days (IQR: 0.9-4.5 days). In summary, our model shows that remdesivir reduces viral production from infected cells by a factor 2, leading to a median reduction of 0.7 days in the time to viral clearance compared to SoC. The efficacy was larger in patients with high level of viral load at treatment initiation. One sentence summaryRemdesivir reduces the time to SARS-CoV-2 clearance by 1 day in hospitalized patients, and up to 3 days in those with high viral load at admission.

Remdesivir for the Treatment of Hospitalised Patients with COVID-19 (DisCoVeRy): A Randomised, Controlled, Open-Label Trial (preprint)

Background: The antiviral efficacy of remdesivir is still controversial. We aimed at evaluating its clinical effectiveness in patients with COVID-19 requiring oxygen and/or ventilator support.Methods: In this European multicentre, open-label, parallel-group, randomised, controlled trial in adults hospitalised with COVID-19 (DisCoVeRy, NCT04315948; EudraCT2020-000936-23), participants were randomly allocated to receive usual standard of care alone or in combination with intravenous remdesivir (200 mg on day 1, then 100 mg once-daily for 9 days or until discharge). Treatment assignation was performed via web-based randomisation stratified on illness severity and administrative European region. The primary outcome was the clinical status at day 15 measured by the WHO 7-point ordinal scale, assessed in the intention-to-treat population.Findings: Between March 22nd, 2020 and January 21st, 2021, 857 participants were randomised to one of the two arms in 5 European countries and 832 participants were included for the evaluation of remdesivir (control, n=418; remdesivir, n=414). There was no difference in the clinical status neither at day 15 between treatment groups (OR for remdesivir, 0.98, 95% CI, 0.77 to 1.25, P=0.85) nor at day 29. The proportion of deaths at day 28 was not significantly different between control (8.9%) and remdesivir (8.2%) treatment groups (OR for remdesivir, 0.93 95%CI 0.57 to 1.52, P=0.77). There was also no difference on SARS-CoV-2 viral kinetics (effect of remdesivir on viral load slope, -0.004 log10 cp/10,000 cells/day, 95% CI, -0.03 to 0.02, P=0.75). There was no significant difference in the occurrence of Serious Adverse Events between treatment groups.Interpretation: The use of remdesivir for the treatment of hospitalised patients with COVID-19 was not associated with clinical improvement at day 15 or day 29, nor with a reduction in mortality, nor with a reduction in SARS-CoV-2 RNA.Trial Registration: DisCoVeRy, NCT04315948; EudraCT2020-000936-23Funding: European Union Commission, French Ministry of Health, DIM One Health Île-de-France, REACTing, Fonds Erasme-COVID-ULB; Belgian Health Care Knowledge Centre (KCE)Declaration of Interests: Dr. Costagliola reports grants and personal fees from Janssen, personal fees from Gilead, outside the submitted work. Dr. Mentré reports grants from INSERM Reacting (French Government), grants from Ministry of Health (French Government), grants from European Commission, during the conduct of the study; grants from Sanofi, grants from Roche, outside the submitted work. Dr. Hites reports grants from The Belgian Center for Knowledge (KCE), grants from Fonds Erasme-COVID-ULB, during the conduct of the study; personal fees from Gilead, outside the submitted work. Dr. Mootien reports non-financial support from GILEAD, outside the submitted work. Dr. Gaborit reports non-financial support from Gilead, non- financial support from MSD, outside the submitted work. Dr. Botelho-Nevers reports other from Pfizer, other from Janssen, outside the submitted work. Dr. Lacombe reports personal fees and non-financial support from Gilead, personal fees and non-financial support from Janssen, personal fees and non-financial support from MSD, personal fees and non-financial support from ViiV Healthcare, personal fees and non-financial support from Abbvie, during the conduct of the study. Dr. Wallet reports personal fees and non-financial support from Jazz pharmaceuticals, personal fees and non-financial support from Novartis, personal fees and nonPage financial support from Kite-Gilead, outside the submitted work. Dr. Kimmoun reports personal fees from Aguettan, personal fees from Aspen, outside the submitted work. Dr. Thiery reports personal fees from AMGEN, outside the submitted work. Dr. Burdet reports personal fees from Da Volterra, personal fees from Mylan Pharmaceuticals, outside the submitted work. Dr. Poissy reports personal fees from Gilead for lectures, outside the submitted work. Dr. Goehringer reports personal fees from Gilead Sciences, non-financial support from Gilead Sciences, grants from Biomerieux, non-financial support from Pfizer, outside the submitted work. Dr. Peytavin reports personal fees from Gilead Sciences, personal fees from Merck France, personal fees from ViiV Healthcare, personal fees from TheraTechnologies, outside the submitted work. Dr. Danion reports personal fees from Gilead, outside the submitted work. Dr. Raffi reports personal fees from Gilead, personal fees from Janssen, personal fees from MSD, personal fees from Abbvie, personal fees from ViiV Healthcare, personal fees from Theratechnologies, personal fees from Pfizer, outside the submitted work. Dr. Gallien reports personal fees from Gilead, personal fees from Pfizer, personal fees from ViiV, personal fees from MSD, outside the submitted work; and has received consulting fee from Gilead in August 2020 to check the registration file of remdesivir for the French administration. Dr. Nseir reports personal fees from MSD, personal fees from Pfizer, personal fees from Gilead, personal fees from Biomérieux, personal fees from BioRad, outside the submitted work. Dr. Lefèvre reports personal fees from Mylan, personal fees from Gilead, outside the submitted work. Dr. Guedj reports personal fees from Roche, outside the submitted work. Other authors have nothing to disclose.Ethics Approval Statement: The trial was approved by the Ethics Committee (CPP Ile-de-France-III, approval #20.03.06.51744), and is sponsored by the Institut national de la santé et de la recherche médicale (Inserm, France); it was conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from all included participants (or their legal representatives if unable to consent). The present analysis is based on the protocol v11.0 of December 12th, 2020.

Two original observations concerning bacterial infections in COVID-19 patients hospitalized in intensive care units during the first wave of the epidemic in France (preprint)

Among 197 COVID-19 patients hospitalized in ICU, 88 (44.7%) experienced at least one bacterial infection, with pneumonia (39.1%) and bloodstream infections (15,7%) being the most frequent. Unusual findings include frequent suspicion of bacterial translocations originating from the digestive tract as well as bacterial persistence in the lungs despite adequate therapy.

Antiviral drugs in hospitalized patients with COVID-19 - the DisCoVeRy trial (preprint)

Background: Lopinavir/ritonavir, lopinavir/ritonavir-interferon (IFN)-beta-1a and hydroxychloroquine efficacy for COVID-19 have been evaluated, but detailed evaluation is lacking. Objective: To determine the efficacy of lopinavir/ritonavir, lopinavir/ritonavir-IFN-beta-1a, hydroxychloroquine or remdesivir for improving the clinical, virological outcomes in COVID-19 inpatients. Design: Open-label, randomized, adaptive, controlled trial. Setting: Multi-center trial with patients from France. Participants: 583 COVID-19 inpatients requiring oxygen and/or ventilatory support Intervention: Standard of care (SoC, control), SoC plus lopinavir/ritonavir (400 mg lopinavir and 100 mg ritonavir every 12h for 14 days), SoC plus lopinavir/ritonavir plus IFN-beta-1a (44 micrograms of subcutaneous IFN-beta-1a on days 1, 3, and 6), SoC plus hydroxychloroquine (400 mg twice on day 1 then 400 mg once daily for 9 days) or SoC plus remdesivir (200 mg intravenously on day 1 then 100 mg once-daily for hospitalization duration or 10 days). Measurements: The primary outcome was the clinical status at day 15, measured by the WHO 7-point ordinal scale. Secondary outcomes included SARS-CoV-2 quantification in respiratory specimens and safety analyses. Results: Adjusted Odds Ratio (aOR) for the WHO 7-point ordinal scale were not in favor of investigational treatments: lopinavir/ritonavir versus control, aOR 0.83, 95%CI, 0.55 to 1.26, P=0.39; lopinavir/ritonavir-IFN-beta-1a versus control, aOR 0.69, 95%CI, 0.45 to 1.04, P=0.08; hydroxychloroquine versus control, aOR 0.93, 95%CI, 0.62 to 1.41, P=0.75. No significant effect on SARS-CoV-2 RNA clearance in respiratory tract was evidenced. Lopinavir/ritonavir-containing treatments were significantly associated with more SAE. Limitations: Not a placebo-controlled, no anti-inflammatory agents tested. Conclusion: No improvement of the clinical status at day 15 nor SARS-CoV-2 RNA clearance in respiratory tract specimens by studied drugs. This comforts the recent Solidarity findings. Registration: NCT04315948. Funding: PHRC 2020, Dim OneHealth, REACTing

High-risk exposure without personal protective equipment and infection with SARS-CoV-2 in healthcare workers: results of the CoV-CONTACT prospective cohort (preprint)

Objective: We aimed to estimate the risk of infection in Healthcare workers (HCWs) following a high-risk exposure without personal protective equipment (PPE). Methods: We conducted a prospective cohort in HCWs who had a high-risk exposure to SARS-CoV-2-infected subject without PPE. Daily symptoms were self-reported for 30 days, nasopharyngeal swabs for SARS-CoV-2 RT-PCR were performed at inclusion and at days 3, 5, 7 and 12, SARS-CoV-2 serology was assessed at inclusion and at day 30. Confirmed infection was defined by positive RT-PCR or seroconversion, and possible infection by one general and one specific symptom for two consecutive days. Results: Between February 5th and May 30th, 2020, 154 HCWs were enrolled within 14 days following one high-risk exposure to either a hospital patient (70/154; 46.1%) and/or a colleague (95/154; 62.5%). At day 30, 25.0% had a confirmed infection (37/148; 95%CI, 18.4%; 32.9%), and 43.9% (65/148; 95%CI, 35.9%; 52.3%) had a confirmed or possible infection. Factors independently associated with confirmed or possible SARS-CoV-2 infection were being a pharmacist or administrative assistant rather than being from medical staff (adjusted OR (aOR)=3.8, CI95%=1.3;11.2, p=0.01), and exposure to a SARS-CoV-2-infected patient rather than exposure to a SARS-CoV-2-infected colleague (aOR=2.6, CI95%=1.2;5.9, p=0.02). Among the 26 HCWs with a SARS-CoV-2-positive nasopharyngeal swab, 7 (26.9%) had no symptom at the time of the RT-PCR positivity. Conclusions: The proportion of HCWs with confirmed or possible SARS-CoV-2 infection was high. There were less occurrences of high-risk exposure with patients than with colleagues, but those were associated with an increased risk of infection.

Repurposed prophylaxis strategies for COVID-19: a systematic review (preprint)

Introduction Efficient therapeutic strategies are needed to counter the COVID-19 pandemic, caused by the SARS- CoV-2 virus. In a context where specific vaccines are not yet available, the containment of the pandemic would be facilitated with efficient prophylaxis. Methods We screened several clinical trials repositories and platforms in search of the prophylactic strategies that are investigated against COVID-19 in late April 2020. Results Up to April 27, 2020, we found 68 clinical trials targeting medical workers (n=43, 63%), patients relatives (n=16, 24%) or individuals at risk of severe COVID-19 (n=5, 7%). (Hydroxy)chloroquine was the most frequently evaluated treatment (n=46, 68%), before BCG vaccine (n=5, 7%). Sixty-one (90%) clinical trials were randomized with a median of planned inclusions of 600 (IQR 255-1515). Conclusion The investigated prophylaxis strategies cover both pre- and post-exposure prophylaxis and study numerous immune enhancers and antivirals, although most research efforts are focused on (hydroxy)chloroquine.