Discussion
Our team has previously published a very controversial study which involved a small group of patients hospitalised for COVID-19 and treated with either HCQ alone or with HCQ plus AZT. This research was supposed to include a control group, as it was not randomised (10). By chance, we had also carried out diagnostic work in different hospital centres which were not included in the research on the evolution of viral load according to these treatments, which served as controls. This work has been highly cited, triggering either strongly hostile or strongly supportive positions. Few teams have been able to carry out comparable studies. In order to carry out such studies, it is necessary to have access to data on patients who have been treated over several days and for whom their regular viral loads have been assessed until negativization, as recommended for hospital discharge. In addition, some studies only report late viral loads without considering or integrating the date of negativization of the viral load, which was the objective of our first study. This first study was confirmed by a study on 3 737 patients showing through principal component analysis that the treatment was associated with a decrease in viral load (12). In the current study, we wanted to evaluate viral clearance in patients who could actually be analysed according to the different treatments they received, including treatment with and without HCQ, and treatment with the combination of HCQ plus AZT. The results presented herein confirm those of the first study we carried out: the virus disappeared more rapidly in the nasopharynx of patients treated with HCQ and AZT, than in other patients, all of whom were treated with an antiviral and/or anti-inflammatory drug. This study avoids a certain number of biases. The treatment dosage was always the same, whereas in other trials these dosages are either lower and probably inactive (19), or in the toxic zone of the drug (20). Furthermore, patients were all treated in the same place by the same team and, therefore, the standard of care was the same for all patients, even if it evolved over time. There is, therefore, no heterogeneity which can arise in multicentre studies. Since the beginning of the outbreak, the cut-off point for defining PCR negativity is the same, at 35 cycles on our apparatus, a cut-off which has been confirmed by several thousand in vitro viral cultures. From 35 cycles onwards, there is no longer any live virus in the inoculated samples [20]. Taken as a whole, we found that HCQ treatment significantly increased the probability of viral clearance by 20% independently of age, time to symptoms and initial viral load. This was confirmed after accounting for the difference in mortality between the HCQ-treated and untreated groups by multivariable Fine-Gray sub-distribution hazard model (21) with a similar 20% risk difference. The median time to negative PCR was decreased by 2 days (6 vs 8 days), which may have important consequences at the individual (decreased risk of virus-related complications) and public health level (contagiousness, epidemic dynamics). In addition, we were able to show that this statistical effect was specific to HCQ treatment and not to HCQ-AZ dual therapy, in favor of a specific biological effect of HCQ for nasopharyngeal viral clearance. The weakness of this study is that, being a single-centre study, the efficacy of treatment is partly due to being managed by a particular team who have treated more than 30,000 people, and the general quality of that management and the experience of the practitioners has probably played a role in both compliance by and the evolution of the patients treated. This means that the results here can be generalised only to similar patients, and a similar organisation of care, and cannot be extrapolated in their entirety to other centres or in multicentre studies.
REFERENCE LIST
1. Schooley RT. Correlation between viral load measurements and outcome in clinical trials of antiviral drugs. AIDS. 1995 Dec;9 Suppl 2:S15–9.
2. van Wyk J, Ajana F, Bisshop F, De Wit S, Osiyemi O, Portilla Sogorb J, et al. Efficacy and Safety of Switching to Dolutegravir/Lamivudine Fixed-Dose 2-Drug Regimen vs Continuing a Tenofovir Alafenamide-Based 3- or 4-Drug Regimen for Maintenance of Virologic Suppression in Adults Living With Human Immunodeficiency Virus Type 1: Phase 3, Randomized, Noninferiority TANGO Study. Clin Infect Dis. 2020 Nov 5;71(8):1920–9.
3. Chanouzas D, Dyall L, Nightingale P, Ferro C, Moss P, Morgan MD, et al. Valaciclovir to prevent Cytomegalovirus mediated adverse modulation of the immune system in ANCA-associated vasculitis (CANVAS): study protocol for a randomised controlled trial. Trials. 2016 Jul 22;17(1):338.
4. Zhang W, Chen Y, Chen L, Guo R, Zhou G, Tang L, et al. The clinical utility of plasma Epstein-Barr virus DNA assays in nasopharyngeal carcinoma: the dawn of a new era?: a systematic review and meta-analysis of 7836 cases. Medicine (Baltimore). 2015 May;94(20):e845.
5. Asberg A, Humar A, Rollag H, Jardine AG, Mouas H, Pescovitz MD, et al. Oral valganciclovir is noninferior to intravenous ganciclovir for the treatment of cytomegalovirus disease in solid organ transplant recipients. Am J Transplant. 2007 Sep;7(9):2106–13.
6. Ahmad A, Eze K, Noulin N, Horvathova V, Murray B, Baillet M, et al. EDP-938, a Respiratory Syncytial Virus Inhibitor, in a Human Virus Challenge. N Engl J Med. 2022 Feb 17;386(7):655–66.
7. Biber A, Harmelin G, Lev D, Ram L, Shaham A, Nemet I, et al. The effect of ivermectin on the viral load and culture viability in early treatment of nonhospitalized patients with mild COVID-19 - a double-blind, randomized placebo-controlled trial. Int J Infect Dis. 2022 Sep;122:733–40.
8. Rojas M, Rodríguez Y, Hernández JC, Díaz-Coronado JC, Vergara JAD, Vélez VP, et al. Safety and efficacy of convalescent plasma for severe COVID-19: a randomized, single blinded, parallel, controlled clinical study. BMC Infect Dis. 2022 Jun 27;22(1):575.
9. Ventura-López C, Cervantes-Luevano K, Aguirre-Sánchez JS, Flores-Caballero JC, Alvarez-Delgado C, Bernaldez-Sarabia J, et al. Treatment with metformin glycinate reduces SARS-CoV-2 viral load: An in vitro model and randomized, double-blind, Phase IIb clinical trial. Biomed Pharmacother. 2022 Aug;152:113223.
10. Gautret P, Lagier JC, Parola P, Hoang VT, Meddeb L, Mailhe M, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial. Int J Antimicrob Agents. 2020 Jul;56(1):105949.
11. Gautret P, Hoang VT, Lagier JC, Raoult D. Effect of hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial, an update with an intention-to-treat analysis and clinical outcomes. International Journal of Antimicrobial Agents. 2021 Jan 1;57(1):106239.
12. Lagier JC, Million M, Gautret P, Colson P, Cortaredona S, Giraud-Gatineau A, et al. Outcomes of 3,737 COVID-19 patients treated with hydroxychloroquine/azithromycin and other regimens in Marseille, France: A retrospective analysis. Travel Med Infect Dis. 2020 Aug;36:101791.
13. Xu K, Chen Y, Yuan J, Yi P, Ding C, Wu W, et al. Factors Associated With Prolonged Viral RNA Shedding in Patients with Coronavirus Disease 2019 (COVID-19). Clin Infect Dis. 2020 Jul 28;71(15):799–806.
14. Hirai N, Nishioka Y, Sekine T, Nishihara Y, Okuda N, Nishimura T, et al. Factors associated with viral clearance periods from patients with COVID-19: A retrospective observational cohort study. J Infect Chemother. 2021 Jun;27(6):864–8.
15. Owusu D, Pomeroy MA, Lewis NM, Wadhwa A, Yousaf AR, Whitaker B, et al. Persistent SARS-CoV-2 RNA Shedding Without Evidence of Infectiousness: A Cohort Study of Individuals With COVID-19. J Infect Dis. 2021 Oct 28;224(8):1362–71.
16. Long H, Zhao J, Zeng HL, Lu QB, Fang LQ, Wang Q, et al. Prolonged viral shedding of SARS-CoV-2 and related factors in symptomatic COVID-19 patients: a prospective study. BMC Infect Dis. 2021 Dec 27;21(1):1282.
17. Puhach O, Meyer B, Eckerle I. SARS-CoV-2 viral load and shedding kinetics. Nat Rev Microbiol. 2023 Mar;21(3):147–61.
18. Jaafar R, Aherfi S, Wurtz N, Grimaldier C, Hoang VT, Colson P, et al. Correlation between 3790 qPCR positives samples and positive cell cultures including 1941 SARS-CoV-2 isolates. Clin Infect Dis. 2020 Sep 28;
19. Ader F, Peiffer-Smadja N, Poissy J, Bouscambert-Duchamp M, Belhadi D, Diallo A, et al. 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. Clin Microbiol Infect. 2021 May 25;
20. RECOVERY Collaborative Group, Horby P, Mafham M, Linsell L, Bell JL, Staplin N, et al. Effect of Hydroxychloroquine in Hospitalized Patients with Covid-19. N Engl J Med. 2020 Nov 19;383(21):2030–40.
21. Fine JP, Gray RJ. A Proportional Hazards Model for the Subdistribution of a Competing Risk. Journal of the American Statistical Association. 1999 Jun 1;94(446):496–509.