Category: Clinical Trial

A Systematic Review of Trials Currently Investigating Therapeutic Modalities for Post-Acute COVID-19 Syndrome and Registered on World Health Organization International Clinical Trials Platform

Abstract:

Background: Post-acute coronavirus 2019 (COVID-19) syndrome (PACS) is a well-recognized complex systemic disease that is associated with substantial morbidity. There is a paucity of established interventions to treat patients with this syndrome.

Objectives: To systematically review registered trials currently investigating therapeutic modalities for PACS.

Data sources: Search was conducted up to the 16th of September 2022 using the COVID-19 section of the World Health Organization (WHO) Internal Clinical Trials Registry Platform.

Study eligibility criteria, participants, and interventions: Interventional clinical trials of any sample size examining any therapeutic modality targeting persistent symptoms among individuals after diagnosis with COVID-19.

Methods: Data on trial characteristics and intervention characteristics were collected and summarized.

Results: After screening 17125 trials, 388 trials from 42 countries were eligible. 331 trials tested mono-therapeutic strategies, while 39 trials included a combination of interventions. Among the 824 primary outcomes identified, there were more than 300 different outcomes. Rehabilitation was the most employed class of intervention with 169 trials. We encountered 76 trials examining pharmacological agents of various classes with the most common agent being colchicine. Complementary and alternative medicine encompassed 64 trials exploring Traditional Chinese Medicine, Ayurveda, homeopathic medications, naturopathic medications, vitamins, dietary supplements, and botanicals. Psychotherapeutic and educational interventions were also employed with 12 and 4 trials, respectively. Other interventions including transcranial current direct stimulation, transcutaneous auricular vagus nerve stimulation, general electrical stimulation, cranial electrotherapy stimulation, various stem cell interventions, and oxygen therapy interventions were also employed.

Conclusion: We identified 388 registered trials with a high degree of heterogeneity exploring 144 unique interventions for PACS. Most target general alleviation of symptoms. There is a need for further high-quality and methodologically robust PACS treatment trials conducted with standardization of outcomes while following WHO’s recommendation for uniform evaluation and treatment.

Source: Fawzy NA, Shaar BA, Taha R, Arabi TZ, Sabbah BN, Alkodaymi MS, Omrani OA, Makhzoum T, Almahfoudh NE, Al-Hammad QA, Hejazi W, Obeidat Y, Osman N, Al-Kattan KM, Berbari EF, Tleyjeh IM. A Systematic Review of Trials Currently Investigating Therapeutic Modalities for Post-Acute COVID-19 Syndrome and Registered on World Health Organization International Clinical Trials Platform. Clin Microbiol Infect. 2023 Jan 12:S1198-743X(23)00009-5. doi: 10.1016/j.cmi.2023.01.007. Epub ahead of print. PMID: 36642173; PMCID: PMC9837206. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9837206/ (Full text)

Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome: an open-label trial

Abstract:

Background: Wasabi (Eutrema japonicum) is a common pungent spice used in Japan. 6-Methylsulfinylhexyl isothiocyanate (6-MSITC) found in the rhizome of wasabi has been shown to have anti-inflammatory and antioxidant effects, as well as improve neuroinflammation and memory. Therefore, we hypothesized that these effects would be beneficial for treating myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The present study was conducted to investigate the effectiveness of wasabi extract containing 6-MSITC on ME/CFS in an open-label trial.

Methods: Fifteen patients (3 males, 12 females, 20-58 years old) were orally administered wasabi extract (9.6 mg of 6-MSITC/day) for 12 weeks. The following parameters and test results were compared pre- and post-treatment: performance status (PS), self-rating questionnaires, pressure pain threshold (PPT) on the occiput, Trail Making test-A (TMT-A), and hemodynamic patterns determined by an active standing test.

Results: After treatment with 6-MSITC, PS improved significantly (p = 0.001). Although the scores on the 11-item Chalder Fatigue scale (CFS-11) and numerical rating scale (NRS) of fatigue did not show significant changes, subjective symptoms improved significantly, including headache frequency (4.1 to 3.0 times/week, p = 0.001) and myalgia (4.1 to 2.4 times/week, p = 0.019), NRS brain fog scores (5.7 to 4.5, p = 0.011), difficulty finding appropriate words (4.8 to 3.7, p = 0.015), photophobia (4.8 to 3.5, p = 0.008), and the Profile of Mood Status vigor score (46.9 to 50.0, p = 0.045). The PPT of the right occiput (17.3 to 21.3 kPa, p = 0.01) and TMT-A scores (53.0 to 38.1 s, p = 0.007) also changed, suggesting reduced pain sensitivity, and improved cognitive function, respectively. Orthostatic patterns determined by a standing test did not show remarkable changes. There were no serious adverse reactions.

Conclusion: This study suggests that 6-MSITC improves PS as well as subjective symptoms such as pain and cognitive dysfunction, and psychological vitality of patients with ME/CFS. It also improved cognitive performance and increased pain thresholds in these patients. 6-MSITC may be a promising therapeutic option especially for improving cognitive dysfunction associated with ME/CFS.

Source: Oka T, Yamada Y, Lkhagvasuren B, Nakao M, Nakajima R, Kanou M, Hiramatsu R, Nabeshima YI. Clinical effects of wasabi extract containing 6-MSITC on myalgic encephalomyelitis/chronic fatigue syndrome: an open-label trial. Biopsychosoc Med. 2022 Dec 12;16(1):26. doi: 10.1186/s13030-022-00255-0. PMID: 36510244. https://bpsmedicine.biomedcentral.com/articles/10.1186/s13030-022-00255-0 (Full text)

Coenzyme Q10 + alpha lipoic acid for chronic COVID syndrome

Abstract:

Chronic COVID syndrome is characterized by chronic fatigue, myalgia, depression and sleep disturbances, similar to chronic fatigue syndrome (CFS) and fibromyalgia syndrome. Implementations of mitochondrial nutrients (MNs) with diet are important for the clinical effects antioxidant. We examined if use of an association of coenzyme Q10 and alpha lipoic acid (Requpero®) could reduce chronic covid symptoms.

The Requpero study is a prospective observational study in which 174 patients, who had developed chronic-covid syndrome, were divided in two groups: The first one (116 patients) received coenzyme Q10 + alpha lipoic acid, and the second one (58 patients) did not receive any treatment. Primary outcome was reduction in Fatigue Severity Scale (FSS) in treatment group compared with control group. complete FSS response was reached most frequently in treatment group than in control group. A FSS complete response was reached in 62 (53.5%) patients in treatment group and in two (3.5%) patients in control group. A reduction in FSS core < 20% from baseline at T1 (non-response) was observed in 11 patients in the treatment group (9.5%) and in 15 patients in the control group (25.9%) (p < 0.0001).

To date, this is the first study that tests the efficacy of coenzyme Q10 and alpha lipoic acid in chronic Covid syndrome. Primary and secondary outcomes were met. These results have to be confirmed through a double blind placebo controlled trial of longer duration.

Source: Barletta MA, Marino G, Spagnolo B, Bianchi FP, Falappone PCF, Spagnolo L, Gatti P. Coenzyme Q10 + alpha lipoic acid for chronic COVID syndrome. Clin Exp Med. 2022 Aug 22. doi: 10.1007/s10238-022-00871-8. Epub ahead of print. PMID: 35994177.  https://link.springer.com/article/10.1007/s10238-022-00871-8 (Full text)

The Qigong of Prolong Life With Nine Turn Method Relieve Fatigue, Sleep, Anxiety and Depression in Patients With Chronic Fatigue Syndrome: A Randomized Controlled Clinical Study

Abstract

Background: Chronic fatigue syndrome (CFS) is a complex disease of unknown etiology and mechanism. The purpose of this study was to investigate the effect of Prolong Life with Nine Turn Method (PLWNT) Qigong exercise on CFS focusing on fatigue, sleep quality, depression, and anxiety.

Methods: A total of 90 participants diagnosed with CFS were randomly assigned into two parallel groups: PLWNT and cognitive behavioral therapy (CBT). The participants in the PLWNT or CBT group participated in qigong exercise or cognitive behavior education program, respectively, once a week in-person and were supervised online during the remaining 6 days at home, over 12 consecutive weeks. The primary outcome was fatigue (Multi-dimensional Fatigue Inventory 20 [MFI-20]), and secondary outcomes were sleep quality (Pittsburgh Sleep Quality Index [PSQI]), anxiety, depression (Hospital Anxiety and Depression Scale [HADS]), and changes in the Neuropeptide Y (NPY) of peripheral blood.

Results: The within-group comparisons of the PLWNT and CBT groups revealed significant improvement in both groups in MFI-20, PSQI, and HADS scores (P < 0.05). No significant difference were found between the PLWNT and CBT groups, even though the effective rate of the PLWNT group was 62.22%, which is slightly than 50.00% of the CBT group. The fatigue scores in the PLWNT group were positively correlated with sleep degree (r = 0.315) and anxiety degree (r = 0.333), only anxiety degree (r = 0.332) was found to be positively correlated with fatigue in the CBT group. The analysis of peripheral blood showed that NPY decreased after PLWNT intervention but increased significantly in the CBT.

Conclusion: The PLWNT qigong exercise has potential to be an effective rehabilitation method for CFS symptoms including fatigue, sleep disturbance, anxiety, and depression. Future studies should expand study sample size for in-depth investigation to determine the optimal frequency and intensity of PLWNT qigong intervention in CFS patients. The study was registered in the ClinicalTrials.gov database on April 12, 2018, with registration number NCT03496961.

Source: Xie F, You Y, Guan C, Xu J, Yao F. The Qigong of Prolong Life With Nine Turn Method Relieve Fatigue, Sleep, Anxiety and Depression in Patients With Chronic Fatigue Syndrome: A Randomized Controlled Clinical Study. Front Med (Lausanne). 2022 Jun 30;9:828414. doi: 10.3389/fmed.2022.828414. PMID: 35847786; PMCID: PMC9280429. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9280429/ (Full text)

Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study

Abstract:

Background: Up to 37.7% of patients experience symptoms beyond 12 weeks after infection with SARS-CoV-2. To date care for people with long covid has centred around multidisciplinary rehabilitation, self care and self pacing. No pharmacotherapy has been shown to be beneficial.

Methods: In this single centre interventional pre post study, the safety of Low Dose Naltrexone (LDN) was explored in patients with Post COVID-19 Syndrome (PCS), defined by NICE as patients with ongoing symptoms 12 or more weeks after initial infections with SARS-CoV-2 where alternative explanation for symptoms cannot be found. Patients were recruited through a Post COVID clinic, had a baseline quality of life questionnaire in symmetrical Likert format, were prescribed 2 months (1 mg month one, 2 mg month two) of LDN and repeated the same questionnaire at the end of the second month. Patients were monitored to adverse events.

Findings: In total 52 patients participated of whom 40(76.9%) were female. The median age was 43.5 years(IQR 33.2–49). Healthcare workers represented the largest occupational cohort n = 16(34.8%). The median time from diagnosis of COVID-19 until enrolment was 333 days (IQR 171–396.5). Thirty-eight participants (73.1%) were known to commence LDN, two of whom (5.3%) stopped taking LDN post commencement due to new onset diarrhoea and also described fatigue. In total 36(69.2%) participants completed the questionnaire at the end of the two-month period. Improvement was seen in 6 of 7 parameters measured; recovery from COVID-19, limitation in activities of daily living, energy levels, pain levels, levels of concentration and sleep disturbance (p ≤ 0.001), improvement in mood approached but was not significant (p = 0.054).

Conclusions: LDN is safe in patients with PCS and may improve well-being and reduce symptomatology in this cohort. Randomised control trials are needed to further explore this.

Source: Brendan O’Kelly, Louise Vidal, Tina McHugh, James Woo, Gordana Avramovic, John S. Lambert. Safety and efficacy of low dose naltrexone in a long covid cohort; an interventional pre-post study. Brain, Behavior, & Immunity – Health; Volume 24, October 2022, 100485 https://www.sciencedirect.com/science/article/pii/S2666354622000758  (Full text)

Oxaloacetate Treatment For Mental And Physical Fatigue In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long-COVID fatigue patients: a non-randomized controlled clinical trial

Abstract:

Background: There is no approved pharmaceutical intervention for Myalgic Encephalomyelitis/ Chronic Fatigue Syndrome (ME/CFS). Fatigue in these patients can last for decades. Long COVID may continue to ME/CFS, and currently, it is estimated that up to 20 million Americans have significant symptoms after COVID, and the most common symptom is fatigue. Anhydrous Enol-Oxaloacetate, (AEO) a nutritional supplement, has been anecdotally reported to relieve physical and mental fatigue and is diminished in ME/CFS patients. Here, we examine the use of higher dosage AEO as a medical food to relieve pathological fatigue.

Methods: ME/CFS and Long-COVID patients were enrolled in an open label dose escalating “Proof of Concept” non-randomized controlled clinical trial with 500 mg AEO capsules. Control was provided by a historical ME/CFS fatigue trial and supporting meta-analysis study, which showed average improvement with oral placebo using the Chalder Scale of 5.9% improvement from baseline. At baseline, 73.7% of the ME/CFS patients were women, average age was 47 and length of ME/CFS from diagnosis was 8.9 years. The Long-COVID patients were a random group that responded to social media advertising (Face Book) with symptoms for at least 6 months. ME/CFS patients were given separate doses of 500 mg BID (N = 23), 1,000 mg BID (N = 29) and 1000 mg TID (N = 24) AEO for six weeks. Long COVID patients were given 500 mg AEO BID (N = 22) and 1000 mg AEO (N = 21), again over a six-week period. The main outcome measure was to compare baseline scoring with results at 6 weeks with the Chalder Fatigue Score (Likert Scoring) versus historical placebo. The hypothesis being tested was formulated prior to data collection.

Results: 76 ME/CFS patients (73.7% women, median age of 47) showed an average reduction in fatigue at 6 weeks as measured by the “Chalder Fatigue Questionnaire” of 22.5% to 27.9% from baseline (P < 0.005) (Likert scoring). Both physical and mental fatigue were significantly improved over baseline and historical placebo. Fatigue amelioration in ME/CFS patients increased in a dose dependent manner from 21.7% for 500 mg BID to 27.6% for 1000 mg Oxaloacetate BID to 33.3% for 1000 mg TID. Long COVID patients’ fatigue was significantly reduced by up to 46.8% in 6-weeks.

Conclusions: Significant reductions in physical and metal fatigue for ME/CFS and Long-COVID patients were seen after 6 weeks of treatment. As there has been little progress in providing fatigue relief for the millions of ME/CFS and Long COVID patients, anhydrous enol oxaloacetate may bridge this important medical need. Further study of oxaloacetate supplementation for the treatment of ME/CFS and Long COVID is warranted.

Source: Cash, A., Kaufman, D.L. Oxaloacetate Treatment For Mental And Physical Fatigue In Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Long-COVID fatigue patients: a non-randomized controlled clinical trial. J Transl Med 20, 295 (2022). https://doi.org/10.1186/s12967-022-03488-3  https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-022-03488-3 (Full text)

Hyperbaric Oxygen for Treatment of Long COVID Syndrome (HOT-LoCO); Protocol for a Randomised, Placebo-Controlled, Double-Blind, Phase II Clinical Trial

Abstract:

Introduction: Long COVID, where symptoms persist 12 weeks after the initial SARS-CoV-2-infection, is a substantial problem for individuals and society in the surge of the pandemic. Common symptoms are fatigue, post-exertional malaise, and cognitive dysfunction. There is currently no effective treatment, and the underlying mechanisms are unknown although several hypotheses exist, with chronic inflammation as a common denominator. In prospective studies, hyperbaric oxygen therapy (HBOT) has been suggested to be effective for the treatment of similar syndromes such as chronic fatigue syndrome and fibromyalgia. A case series has suggested positive effects of HBOT in Long COVID. This randomised placebo-controlled clinical trial will explore HBOT as a potential treatment for Long COVID.

The primary objective is to evaluate if HBOT improves health related quality of life (HRQoL) for patients with Long COVID compared to placebo/sham. The main secondary objectives are to evaluate whether HBOT improves endothelial function, objective physical performance, and short term HRQoL.

Methods and Analysis: A randomised, placebo-controlled, double-blind, phase II clinical trial in 80 previously healthy subjects debilitated due to Long COVID, with low HRQoL. Clinical data, HRQoL-questionnaires, blood samples, objective tests and activity meter data will be collected at baseline. Subjects will be randomised to a maximum of 10 treatments with hyperbaric oxygen or sham treatment over six weeks. Assessments for safety and efficacy will be performed at six, 13, 26 and 52 weeks, with the primary endpoint (physical domains in RAND-36) and main secondary endpoints defined at 13 weeks after baseline. Data will be reviewed by an independent Data Safety Monitoring Board.

Ethics and Dissemination: The trial is approved by The Swedish National Institutional Review Board (2021-02634) and the Swedish Medical Product Agency (5.1-2020-36673). Positive, negative, and inconclusive results will be published in peer-reviewed scientific journals with open access.

Trial Registration NCT04842448. EudraCT: 2021-000764-30 Strengths and limitations of this trial Strengths -Randomised placebo-controlled, double-blind, parallel groups, clinical trial in compliance with ICH-GCP -Evaluation of safety and efficacy, including objective and explanatory endpoints -Independent Data Safety Monitoring Board (DSMB) Limitations -New syndrome with unknown mechanisms -Power calculation is based on similar syndromes -Selection bias as patients are enrolled from the same post-COVID clinic

Source: Anders Kjellberg, Lina Abdel-Halim, Adrian Hassler, Sara El Gharbi, Sarah Al-Ezerjawi, Emil Boström, Carl Johan Sundberg, John Pernow, Koshiar Medson, Jan Kowalski, Kenny A Rodriguez-Wallberg, Xiaowei Zheng, Sergiu Bogdan Catrina, Michael Runold, Marcus Ståhlberg, Judith Bruchfeld, Malin Nygren-Bonnier, Peter Lindholm. Hyperbaric Oxygen for Treatment of Long COVID Syndrome (HOT-LoCO); Protocol for a Randomised, Placebo-Controlled, Double-Blind, Phase II Clinical Trial. medRxiv 2022.05.20.22275312; doi: https://doi.org/10.1101/2022.05.20.22275312 https://www.medrxiv.org/content/10.1101/2022.05.20.22275312v1

Ginger-indirect moxibustion plus acupuncture versus acupuncture alone for chronic fatigue syndrome: a randomized controlled trial

Abstract:

Objective: To assess the efficacy and safety of ginger-indirect moxibustion for chronic fatigue syndrome (CFS).

Methods: In this central randomized, controlled trial, 290 CFS participants were recruited and randomly allocated to group A (ginger-indirect moxibustion plus acupuncture) or group B (acupuncture alone). The study consisted of a treatment period of 8 weeks with a total of 24 treatments (3 sessions per week, every other day), and a follow-up period of 12 weeks. The outcome was measured by Fatigue Severity Scale (FSS), Psychological Health Report (SPHERE), the Self-rating depression scale (SDS) and the Hamilton anxiety scale (HAMA) at baseline, 2, 4, 6, 8, 12 and 20 weeks.

Results: With the treatment undergoing, the changes of FSS, SPHERE, SDS and HAMA scores in both groups increased gradually, and the effect maintained at the 12th week. Between groups, significantly higher score changes were seen in group A in FSS after 4 weeks treatment (11.94 9.12, 95%: 0.94, 4.7) and in SPHERE after 2 weeks treatment (3.7 2.27, 95%: 0.56, 2.31). But for SDS and HAMA, the improvement did not differ significantly between groups. No severe adverse events were reported.

Conclusion: Ginger-indirect moxibustion is a safe and effective intervention to relieve fatigue and accompanying physical symptoms of CFS.

Source: Tingting MA, Jie WU, Lijie Y, Fen F, Huilin Y, Jinhua Z, Yanjin Z, Qing N, Lirong H, Youbing L, Jue Y, Guiquan C, Tianshu H, Li W, Yuanfang R, Jing T. Ginger-indirect moxibustion plus acupuncture versus acupuncture alone for chronic fatigue syndrome: a randomized controlled trial. J Tradit Chin Med. 2022 Apr;42(2):242-249. doi: 10.19852/j.cnki.jtcm.20211214.003. PMID: 35473345. https://pubmed.ncbi.nlm.nih.gov/35473345/

The use of amantadine in the prevention of progression and treatment of COVID-19 symptoms in patients infected with the SARS-CoV-2 virus (COV-PREVENT): Study rationale and design

Abstract:

Background: COVID-19, a disease caused by infection with the SARS-CoV-2 virus, is asymptomatic or mildly symptomatic in most cases. Some patients, usually burdened with risk factors develop acute respiratory failure and other organ dysfunction. In such cases, the mortality rate is very high despite the use of intensive therapy. Amantadine has complex activity including antiviral, antiinflammatory and dopaminergic effects. This clinical trial will assess the efficacy and safety of amantadine in the prevention of COVID-19 progression toward acute respiratory failure and neurological complications.

Methods and results: The trial will enroll 200 patients who are positive for SARS-CoV-2 infection and have one or more risk factors for worsening the disease. These patients will be included as hospitalized or ambulatory subjects for early treatment of illness. The recruitment will take place in 8 centers covering different regions of Poland. For 14 days they will be given either 200 mg of amantadine a day or placebo. Our hypothesis is a considerable reduction in the number of patients with progression toward respiratory insufficiency or neurological complications thanks to the treatment of amantadine.

Conclusions: Demonstrating the efficacy and safety of amantadine treatment in improving the clinical condition of patients diagnosed with COVID-19 is of great importance in combating the effects of the pandemic. It has potential to influence on the severity and course of neurological complications, which are very common and persist long after the infection as long-COVID syndrome.

Clinical trial registration: www.

Clinicaltrials: gov identification no. NCT04854759; Eudra CT number: 2021-001144-98 (dated 27 February 2021).

Source: Rejdak K, Fiedor P, Bonek R, Goch A, Gala-Błądzińska A, Chełstowski W, Łukasiak J, Kiciak S, Dąbrowski P, Dec M, Król ZJ, Papuć E, Zasybska A, Segiet A, Grieb P. The use of amantadine in the prevention of progression and treatment of COVID-19 symptoms in patients infected with the SARS-CoV-2 virus (COV-PREVENT): Study rationale and design. Contemp Clin Trials. 2022 Apr 4;116:106755. doi: 10.1016/j.cct.2022.106755. Epub ahead of print. PMID: 35390511; PMCID: PMC8978450. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8978450/ (Full text)

Registered clinical trials investigating treatment of long COVID: a scoping review and recommendations for research

Abstract:

Background: A considerable proportion of individuals report persistent, debilitating and disparate symptoms despite resolution of acute COVID-19 infection (i.e. long COVID). Numerous registered clinical trials investigating treatment of long COVID are expected to be completed in 2021–2022. The aim of this review is to provide a scope of the candidate treatments for long COVID. A synthesis of ongoing long COVID clinical trials can inform methodologic approaches for future studies and identify key research vistas.

Methods: Scoping searches were conducted on multiple national and international clinical trial registries. Interventional trials testing treatments for long COVID were selected. The search timeline was from database inception to 28 July 2021.

Results: This scoping review included 59 clinical trial registration records from 22 countries with a total projected enrolment of 6718. Considerable heterogeneity was exhibited amongst component records with respect to the characterization of long COVID (i.e. name, symptoms- including frequency, intensity, trajectory and duration- mode of ascertainment, and definition of acute phase). In addition, the majority of proposed interventions were non-pharmacological and either targeted multiple long COVID symptoms simultaneously, or focussed on treatment of respiratory/pulmonary sequelae. Multiple interventions targeted inflammation, as well as tissue oxygenation and cellular recovery, and several interventions were repurposed from analogous conditions.

Conclusions: The results of this scoping review investigating ongoing clinical trials testing candidate treatments for long COVID suggest that a greater degree of definitional stringency and homogeneity is needed insofar as the characterization of long COVID and inclusion/exclusion criteria.

Source: Ceban F, Leber A, Jawad MY, Yu M, Lui LMW, Subramaniapillai M, Di Vincenzo JD, Gill H, Rodrigues NB, Cao B, Lee Y, Lin K, Mansur RB, Ho R, Burke MJ, Rosenblat JD, McIntyre RS. Registered clinical trials investigating treatment of long COVID: a scoping review and recommendations for research. Infect Dis (Lond). 2022 Mar 14:1-11. doi: 10.1080/23744235.2022.2043560. Epub ahead of print. PMID: 35282780; PMCID: PMC8935463. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8935463/ (Full text)