ArticleProceedings of the National Academy of Sciences of the United States of America2020
Favipiravir at high doses has potent antiviral activity in SARS-CoV-2-infected hamsters, whereas hydroxychloroquine lacks activity.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04981379 (Efficacy and Safety of the Use of Hydroxychloroquine, Favipiravir or Hydroxychloroquine + Favipiravir in Early SARS-CoV-2), which is not on this map. Cited by 166 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Efficacy and Safety of the Use of Hydroxychloroquine, Favipiravir or Hydroxychloroquine + Favipiravir in Early SARS-CoV-2 (COVID-19) Treatment
Who cites it
166 citing papers in PubMed, 2 syntheses or guidelines pooled it, 284 citations in OpenAlex.
- Intranasal administration of convalescent plasma protects against SARS-CoV-2 infection in hamsters.EBioMedicine · 2023Pooled it
- Prophylaxis for COVID-19: a systematic review.Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases · 2021Pooled it
- Population pharmacokinetic/pharmacodynamic modelling to evaluate favipiravir in combination with lopinavir-ritonavir in patients with COVID-19.British journal of clinical pharmacology · 2026Trial
- Optimal Dose and Safety of Intravenous Favipiravir in Hospitalized Patients With COVID-19: A Dose-Escalating, Randomized Controlled Phase Ib Study.Clinical pharmacology and therapeutics · 2026Trial
- Clinical antiviral efficacy of favipiravir in early COVID-19 (PLATCOV): an open-label, randomised, controlled, adaptive platform trial.BMC infectious diseases · 2024Trial
- Favipiravir in patients hospitalised with COVID-19 (PIONEER trial): a multicentre, open-label, phase 3, randomised controlled trial of early intervention versus standard care.The Lancet. Respiratory medicine · 2023Trial
- Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2023Trial
- Favipiravir, lopinavir-ritonavir, or combination therapy (FLARE): A randomised, double-blind, 2 × 2 factorial placebo-controlled trial of early antiviral therapy in COVID-19.PLoS medicine · 2022Trial
- Safety and efficacy of hydroxychloroquine for treatment of non-severe COVID-19 among adults in Uganda: a randomized open label phase II clinical trial.BMC infectious diseases · 2021Trial
- Itraconazole for COVID-19: preclinical studies and a proof-of-concept randomized clinical trial.EBioMedicine · 2021Trial
- Randomized controlled open label trial on the use of favipiravir combined with inhaled interferon beta-1b in hospitalized patients with moderate to severe COVID-19 pneumonia.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2021Trial
- Towards broader-spectrum direct-acting antivirals against RNA viruses.Nature reviews. Microbiology · 2026Review
- Integrated in vivo and transcriptomic analyses of lethal Oropouche virus infection reveal suppression of pathogenic host responses by antiviral therapy.PLoS pathogens · 2026Article
- Favipiravir tissue distribution and inhibitory quotients in preclinical models: towards a pipeline for evidence-based antiviral repurposing.The Journal of antimicrobial chemotherapy · 2026Article
- The relationship between plasma favipiravir concentrations and clinical outcomes in COVID-19.ERJ open research · 2026Article
- Clinical Manifestations and Immunological Impacts in Co-Infections and Sequential Infections of SARS-CoV-2 and Arboviruses.Current microbiology · 2026Review
- Favipiravir treatment in Thai children with COVID-19: effectiveness, safety, and modeling drug exposure.Asian biomedicine : research, reviews and news · 2026Article
- COVID-19-related inflammation of the placenta impedes fetal development in pregnant hamsters.Nature communications · 2026Article
- Investigation of the functional hot-spot residues of an enzyme by real-time monitoring of the enzymatic reaction using NMR and computational approaches.Scientific reports · 2026Article
- Andrographolide Inhibits Rabies Virus Replication.Transboundary and emerging diseases · 2026Article
106 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
35 authors at 5 institutions in 4 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the globe after its emergence in Wuhan in December 2019. With no specific therapeutic and prophylactic options available, the virus has infected millions of people of which more than half a million succumbed to the viral disease, COVID-19. The urgent need for an effective treatment together with a lack of small animal infection models has led to clinical trials using repurposed drugs without preclinical evidence of their in vivo efficacy. We established an infection model in Syrian hamsters to evaluate the efficacy of small molecules on both infection and transmission. Treatment of SARS-CoV-2-infected hamsters with a low dose of favipiravir or hydroxychloroquine with(out) azithromycin resulted in, respectively, a mild or no reduction in virus levels. However, high doses of favipiravir significantly reduced infectious virus titers in the lungs and markedly improved lung histopathology. Moreover, a high dose of favipiravir decreased virus transmission by direct contact, whereas hydroxychloroquine failed as prophylaxis. Pharmacokinetic modeling of hydroxychloroquine suggested that the total lung exposure to the drug did not cause the failure. Our data on hydroxychloroquine (together with previous reports in macaques and ferrets) thus provide no scientific basis for the use of this drug in COVID-19 patients. In contrast, the results with favipiravir demonstrate that an antiviral drug at nontoxic doses exhibits a marked protective effect against SARS-CoV-2 in a small animal model. Clinical studies are required to assess whether a similar antiviral effect is achievable in humans without toxic effects.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.