COVID19COPCOVNCT04303507
Chloroquine/ Hydroxychloroquine Prevention of Coronavirus Disease (COVID-19) in the Healthcare Setting
A study testing Chloroquine or Hydroxychloroquine in people with COVID19 and Coronavirus, run by University of Oxford at 25 sites in 10 countries.
Trial summary
The study is a double-blind, randomised, placebo-controlled trial that will be conducted primarily in healthcare settings and other facilities directly involved in COVID-19 case management. We will recruit healthcare workers and other persons at risk of contracting COVID-19, who can be followed reliably for 5 months. Read more about this study
- Who is it for?
- Ages 16 years and olderHealthy volunteers can take part
- Conditions the study is for
- COVID19, Coronavirus, Acute Respiratory Illnesses
- What is being tested?
- Chloroquine or Hydroxychloroquine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 4,652 participants
- Where
- 25 sitesin 10 countries
- Study dates
- 29 Apr 2020to 22 Mar 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Participant is willing and able to give informed consent for participation in the study and agrees with the study and its conduct
- Agrees not to self-medicate with chloroquine, hydroxychloroquine or other potential antivirals
- Adults (exact age is dependent on countries) less than 70 years old at the time of consent
- Not previously diagnosed with COVID-19
- Not currently symptomatic with an ARI
- Participant is a healthcare worker or is a person at risk of contracting COVID-19.
- Possesses an internet-enabled smartphone (Android or iOS)
Who cannot join
- Hypersensitivity reaction to chloroquine, hydroxychloroquine or 4-aminoquinolines
- Contraindication to taking chloroquine as prophylaxis e.g. known epileptic, known creatinine clearance < 10 ml/min
- Already taking chloroquine, hydroxychloroquine or 4-aminoquinolines, or history of these medications within the previous 7 days
- Taking prohibited medications
- Known retinal disease
- Inability to be followed up for the trial period
Show all 23Show fewer
- Known prolonged QT syndrome (however ECG is not required at baseline)
- Known pregnancy or women who are actively trying to become pregnant
- Prior diagnosis of porphyria
- Previously received any dose of COVID-19 vaccine
- The investigator may consult the physician's guidance documents for any further questions regarding eligibility of potential participants.
- Prohibited medications for the purpose of study enrollment include:
- Antiarrhythmic medications: digoxin, amiodarone, sotalol, flecainide
- Antiparasitic/malarial agents: mefloquine, halofantrine, praziquantel
- Antibiotics: levofloxacin, moxifloxacin, ciprofloxacin, azithromycin, clarithromycin, erythromycin
- Antifungal drugs: fluconazole, ketoconazole, itraconazole, terfenadine
- Psychoactive drugs: lithium, quetiapine, chlorpromazine, thioridazine, ziprasidone, haloperidol, droperidol, methadone
- Migraine treatment: sumatriptan
- Antihistamines: astemizole
- Antiemetics: prochlorperazine, metoclopramide
- Cancer treatments: abiraterone, dabrafenib, dacomitinib, enzalutamide, idelalisib, mitotane
- Other specific drugs: ciclosporin, conivaptan, agalsidase alfa or beta, mifepristone, stiripentol
- PrincipaI Investigators will also be directed to crediblemeds.org to check other agents that may prolong QT interval
Trial locations and contacts
25 sites in 10 countries.
25 sites in 10 countries
United Kingdom8 sites
Birmingham & Solihull Mental Health NHS Trust
Birmingham, B1 3RB
Brighton and Sussex University Hospitals NHS Trust
Brighton, BN2 5BE
University Hospitals Coventry and Warwickshire NHS Trust
Coventry, CV2 2DX
Rotherham, Doncaster And South Humber NHS Foundation Trust
Doncaster, DN4 8QN
The Dudley Group NHS Foundation Trust
Dudley, West Midlands, DY1 2HQ
University Hospitals Of Morecambe Bay NHS Foundation Trust
Kendal, Cumbria, LA9 7RG
Imperial College Healthcare NHS Trust
London, W2 1NY
Oxford University Hospital NHS Foundation Trust
Oxford, OX3 9DU
Indonesia5 sites
Bunda Thamrin Hospital
Medan, North Sumatra, 20112
Murni Teguh Memorial Hospital
Medan, North Sumatra, 20231
Airlangga University Hospital (UNAIR)
Surabaya, East Java, 60115
Husada Utama Hospital
Surabaya, East Java, 60131
Sardjito Hospital
Yogyakarta, 55281
Benin2 sites
Centre Hospitalier et Universitaire de Zone Abomey-Calavi
Abomey-Calavi
Hospital De Zone Allada
Allada
Côte d’Ivoire2 sites
University Hospital Center of Angre
Abidjan, BP 54378
University Hospital Center of Bouake
Bouaké, BP 1174
Kenya2 sites
Fountain Healthcare Hospital
Eldoret
Mbagathi County Hospital
Nairobi
Mali2 sites
The Bamako Hospital of Dermatology
Bamako, BP251
Hospital Of Mali
Bamako, BP3333
Thailand1 site
Faculty of Tropical Medicine, Mahidol University
Bangkok, 10400
About this study
Official title: Chloroquine/ Hydroxychloroquine Prevention of Coronavirus Disease (COVID-19) in the Healthcare Setting; a Randomised, Placebo-controlled Prophylaxis Study (COPCOV)
The study is a double-blind, randomised, placebo-controlled trial that will be conducted primarily in healthcare settings and other facilities directly involved in COVID-19 case management. We will recruit healthcare workers and other persons at risk of contracting COVID-19, who can be followed reliably for 5 months. The initial aim was to recruit 40,000 participants and we predict an average of 400-800 participants per site in 50-100 sites.
The participant will be randomised to receive either chloroquine or placebo (1:1 randomisation), or to hydroxychloroquine or placebo (1:1 randomisation). A loading dose of 10mg base/kg (four 155mg tablets for a 60kg subject), followed by 155 mg daily (250mg chloroquine phosphate salt/ 200mg hydroxychloroquine sulphate) will be taken for 3 months.
Read more
If the participant is diagnosed with COVID-19, they will take continue to take the study medication until:
- 90 days after enrolment (i.e., completion of kit)
- hospitalised due to COVID-19 disease (i.e., not for quarantine purposes) in which case they will stop, or
- advised to stop by their healthcare professional for other reasons
Episodes of symptomatic respiratory illness, including symptomatic COVID-19, and clinical outcomes will be recorded in the Case Record Form during the follow-up period.
This study is funded by Wellcome Trust Grant reference 221307/Z/20/Z.
- Conditions
- COVID19, Coronavirus, Acute Respiratory Illnesses
- Being tested
- Chloroquine or Hydroxychloroquine, Placebo
- Medical subject headings
- COVID-19, Coronavirus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Chloroquine or HydroxychloroquineDrug
A loading dose of 10 mg base/ kg followed by 155 mg daily (250mg chloroquine phosphate salt or 200mg of or hydroxychloroquine sulphate) will be taken for 3 months
PlaceboDrug
Placebo
| Study group | Role | What they receive |
|---|---|---|
| Chloroquine or Hydroxychloroquine | Experimental | In Asia, the participant will receive chloroquine.
In Europe, the participant will receive hydroxychloroquine
Specific drug allocation will be determined by country prior to activation based upon factors such as inventory availability and importation requirements Receives: Drug: Chloroquine or Hydroxychloroquine |
| Placebo | Placebo comparator | Not described Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of symptomatic COVID-19 infections
Number of symptomatic COVID-19 infections will be compared between the chloroquine or hydroxychloroquine and placebo groups
Measured: Approximately 90 days
Secondary outcomes (4)
Symptoms severity of COVID-19
Symptoms severity of COVID-19 will be compared between the two groups using a respiratory severity score.
Measured: Approximately 90 days
Number of asymptomatic cases of COVID-19
Number of asymptomatic cases of COVID-19 will be determined by comparing serology in all participants at time of enrolment and at the end of follow up.
Measured: Approximately 90 days
Number of symptomatic acute respiratory illnesses
Number of symptomatic acute respiratory illnesses will be compared between the chloroquine or hydroxychloroquine and placebo groups.
Measured: Approximately 90 days
Severity of symptomatic acute respiratory illnesses
Severity of symptomatic acute respiratory illnesses will be compared between the chloroquine or hydroxychloroquine and placebo groups.
Measured: Approximately 90 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Mar 2020
- Study start29 Apr 2020
- Primary completion22 Mar 2022
- Study completion22 Mar 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for COVID19Studies of the same condition, open and under way.
- More trials run by University of OxfordThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 4,652 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Oxford
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- William Schilling, MD, Principal investigator, Mahidol Oxford Tropical Medicine Research Unit
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04303507
- Sponsor's protocol ID
- VIR20001
- Acronym
- COPCOV
- Status last verified
- May 2022
- First submitted
- 6 Mar 2020
- Last updated
- 4 Apr 2023
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: With participant's consent, suitably anonymised clinical data and results from blood analyses stored in the database may be shared according to the terms defined in the MORU data sharing policy with other researchers to use in the future.
Publications
Winters J, Schilling WH. Approval delays in multi-country COVID-19 trials: the case of COPCOV and the risk of therapeutic inertia. Trials. 2025 Dec 16;27(1):58. doi: 10.1186/s13063-025-09300-z.
PubMed 41402852Schilling WHK, Mukaka M, Callery JJ, Llewelyn MJ, Cruz CV, Dhorda M, Ngernseng T, Waithira N, Ekkapongpisit M, Watson JA, Chandna A, Nelwan EJ, Hamers RL, Etyang A, Beg MA, Sow S, Yavo W, Allabi AC, Basnyat B, Sharma SK, Amofa-Sekyi M, Yonga P, Adler A, Yuentrakul P, Cope T, Thaipadungpanit J, Rienpradub P, Imwong M, Abdad MY, Blacksell SD, Tarning J, Goudjo FF, Dossou AD, Konate-Toure A, Assi SB, Ouffoue K, Nasronudin N, Rachman BE, Romadhon PZ, Dewanto DD, Heryana MO, Novi T, Pasaribu AP, Mutiara M, Nasution MPR, Khairunnisa K, Dalimunthe FA, Airlangga E, Fahrezzy A, Subronto Y, Ananda NR, Rahardjani M, Rimainar A, Lucinde RK, Timbwa M, Onyango OE, Agutu C, Akech S, Hamaluba M, Kipyego J, Ngachi O, Haidara FC, Traore OY, Diarra F, Khanal B, Dahal P, Shrestha S, Rijal S, Kabore Y, Adehossi E, Guindo O, Qamar FN, Kazi AM, Woodrow CJ, Laird S, Cheeba M, Ayles H, Cheah PY, Taylor WRJ, Batty EM, Chotivanich K, Pukrittayakamee S, Phumratanaprapin W, von Seidlein L, Dondorp A, Day NPJ, White NJ; COPCOV Collaborative Group. Evaluation of hydroxychloroquine or chloroquine for the prevention of COVID-19 (COPCOV): A double-blind, randomised, placebo-controlled trial. PLoS Med. 2024 Sep 12;21(9):e1004428. doi: 10.1371/journal.pmed.1004428. eCollection 2024 Sep.
PubMed 39264960Kabore Y, Vatrinet R, Guindo O, Moussa SH, Schilling WHK, Grais RF. Reflections on Participation in a Trial on Hydroxychloroquine as Prevention for COVID-19 among Health Workers in Niger. Am J Trop Med Hyg. 2023 Aug 14;109(3):511-514. doi: 10.4269/ajtmh.22-0606. Print 2023 Sep 6.
PubMed 37580026Akhtar S, Das JK, Ismail T, Wahid M, Saeed W, Bhutta ZA. Nutritional perspectives for the prevention and mitigation of COVID-19. Nutr Rev. 2021 Feb 11;79(3):289-300. doi: 10.1093/nutrit/nuaa063.
PubMed 33570583
Study at a glance
From the registry record, last updated by the sponsor on 4 Apr 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Chloroquine/ Hydroxychloroquine Prevention of Coronavirus Disease (COVID-19) in the Healthcare Setting; a Randomised, Placebo-controlled Prophylaxis Study (COPCOV)
- ClinicalTrials.gov ID
- NCT04303507
- Acronym / sponsor ID
- COPCOV / VIR20001
- Conditions
- COVID19, Coronavirus, Acute Respiratory Illnesses
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 4,652 participants (actual)
- Lead sponsor
- University of OxfordUniversity, hospital or other
- Study start
- 29 Apr 2020 (actual)
- Primary completion
- 22 Mar 2022 (actual)
- Study completion
- 22 Mar 2022 (actual)
- First posted
- 11 Mar 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The study is a double-blind, randomised, placebo-controlled trial that will be conducted primarily in healthcare settings and other facilities directly involved in COVID-19 case management. We will recruit healthcare workers and other persons at risk of contracting COVID-19, who can be followed reliably for 5 months. The initial aim was to recruit 40,000 participants and we predict an average of 400-800 participants per site in 50-100 sites.
The participant will be randomised to receive either chloroquine or placebo (1:1 randomisation), or to hydroxychloroquine or placebo (1:1 randomisation). A loading dose of 10mg base/kg (four 155mg tablets for a 60kg subject), followed by 155 mg daily (250mg chloroquine phosphate salt/ 200mg hydroxychloroquine sulphate) will be taken for 3 months.
If the participant is diagnosed with COVID-19, they will take continue to take the study medication until:
- 90 days after enrolment (i.e., completion of kit)
- hospitalised due to COVID-19 disease (i.e., not for quarantine purposes) in which case they will stop, or
- advised to stop by their healthcare professional for other reasons
Episodes of symptomatic respiratory illness, including symptomatic COVID-19, and clinical outcomes will be recorded in the Case Record Form during the follow-up period.
This study is funded by Wellcome Trust Grant reference 221307/Z/20/Z.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Chloroquine or Hydroxychloroquine | Experimental | Drug: Chloroquine or HydroxychloroquineIn Asia, the participant will receive chloroquine. In Europe, the participant will receive hydroxychloroquine Specific drug allocation will be determined by country prior to activation based upon factors such as inventory availability and importation requirements |
| Placebo | Placebo comparator | Drug: Placebo |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- Participant is willing and able to give informed consent for participation in the study and agrees with the study and its conduct
- Agrees not to self-medicate with chloroquine, hydroxychloroquine or other potential antivirals
- Adults (exact age is dependent on countries) less than 70 years old at the time of consent
- Not previously diagnosed with COVID-19
- Not currently symptomatic with an ARI
Key exclusion criteria (23 listed)
- Hypersensitivity reaction to chloroquine, hydroxychloroquine or 4-aminoquinolines
- Contraindication to taking chloroquine as prophylaxis e.g. known epileptic, known creatinine clearance < 10 ml/min
- Already taking chloroquine, hydroxychloroquine or 4-aminoquinolines, or history of these medications within the previous 7 days
- Taking prohibited medications
- Known retinal disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Chloroquine or HydroxychloroquineA loading dose of 10 mg base/ kg followed by 155 mg daily (250mg chloroquine phosphate salt or 200mg of or hydroxychloroquine sulphate) will be taken for 3 months | Drug | Chloroquine or Hydroxychloroquine |
| PlaceboPlacebo | Drug | Placebo |
Primary outcome
Number of symptomatic COVID-19 infections
Time frame: Approximately 90 days
Number of symptomatic COVID-19 infections will be compared between the chloroquine or hydroxychloroquine and placebo groups
4 secondary outcomes
Symptoms severity of COVID-19
Time frame: Approximately 90 days
Number of asymptomatic cases of COVID-19
Time frame: Approximately 90 days
Number of symptomatic acute respiratory illnesses
Time frame: Approximately 90 days
Severity of symptomatic acute respiratory illnesses
Time frame: Approximately 90 days
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Apr 2023.
- Derived from this study: PubMed 41402852Winters J, Schilling WH. Approval delays in multi-country COVID-19 trials: the case of COPCOV and the risk of therapeutic inertia. Trials. 2025 Dec 16;27(1):58. doi: 10.1186/s13063-025-09300-z.
- Derived from this study: PubMed 39264960Schilling WHK, Mukaka M, Callery JJ, Llewelyn MJ, Cruz CV, Dhorda M, Ngernseng T, Waithira N, Ekkapongpisit M, Watson JA, Chandna A, Nelwan EJ, Hamers RL, Etyang A, Beg MA, Sow S, Yavo W, Allabi AC, Basnyat B, Sharma SK, Amofa-Sekyi M, Yonga P, Adler A, Yuentrakul P, Cope T, Thaipadungpanit J, Rienpradub P, Imwong M, Abdad MY, Blacksell SD, Tarning J, Goudjo FF, Dossou AD, Konate-Toure A, Assi SB, Ouffoue K, Nasronudin N, Rachman BE, Romadhon PZ, Dewanto DD, Heryana MO, Novi T, Pasaribu AP, Mutiara M, Nasution MPR, Khairunnisa K, Dalimunthe FA, Airlangga E, Fahrezzy A, Subronto Y, Ananda NR, Rahardjani M, Rimainar A, Lucinde RK, Timbwa M, Onyango OE, Agutu C, Akech S, Hamaluba M, Kipyego J, Ngachi O, Haidara FC, Traore OY, Diarra F, Khanal B, Dahal P, Shrestha S, Rijal S, Kabore Y, Adehossi E, Guindo O, Qamar FN, Kazi AM, Woodrow CJ, Laird S, Cheeba M, Ayles H, Cheah PY, Taylor WRJ, Batty EM, Chotivanich K, Pukrittayakamee S, Phumratanaprapin W, von Seidlein L, Dondorp A, Day NPJ, White NJ; COPCOV Collaborative Group. Evaluation of hydroxychloroquine or chloroquine for the prevention of COVID-19 (COPCOV): A double-blind, randomised, placebo-controlled trial. PLoS Med. 2024 Sep 12;21(9):e1004428. doi: 10.1371/journal.pmed.1004428. eCollection 2024 Sep.
- Derived from this study: PubMed 37580026Kabore Y, Vatrinet R, Guindo O, Moussa SH, Schilling WHK, Grais RF. Reflections on Participation in a Trial on Hydroxychloroquine as Prevention for COVID-19 among Health Workers in Niger. Am J Trop Med Hyg. 2023 Aug 14;109(3):511-514. doi: 10.4269/ajtmh.22-0606. Print 2023 Sep 6.
- Derived from this study: PubMed 33570583Akhtar S, Das JK, Ismail T, Wahid M, Saeed W, Bhutta ZA. Nutritional perspectives for the prevention and mitigation of COVID-19. Nutr Rev. 2021 Feb 11;79(3):289-300. doi: 10.1093/nutrit/nuaa063.
- Related InfoLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. With participant's consent, suitably anonymised clinical data and results from blood analyses stored in the database may be shared according to the terms defined in the MORU data sharing policy with other researchers to use in the future.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
William Schilling, MD principal investigator
Mahidol Oxford Tropical Medicine Research Unit
25 sites in 10 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Chloroquine or Hydroxychloroquine in people with COVID19 and Coronavirus, run by University of Oxford at 25 sites in 10 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 23 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Apr 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 25 sites in United Kingdom, Indonesia, Benin, Côte d’Ivoire, Kenya and 5 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of symptomatic COVID-19 infections (time frame: Approximately 90 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04303507, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Apr 2023.