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As high COVID-19 daily cases and highly transmissible variants risk overwhelming countries’ healthcare systems, COPCOV, the world’s last-standing large prophylaxis RCT, faces tight timelines to determine whether chloroquine/ hydroxychloroquine prevents COVID-19

Pie Chart with COPCOV recruitment as of 7th July 2021. A black & white version of the pie chart and a table with figures can be found at https://www.tropmedres.ac/news/recruitment-surges-in-copcov-covid-19-prevention-study/copcov-recruitment-as-of-7-july-2021

COPCOV – the world’s largest trial trying to determine if hydroxychloroquine and chloroquine prevent COVID-19 – has more than doubled recruitment in the past month, with 1332 participants enrolled as of 7 July. Funded by Wellcome and led by MORU, COPCOV has begun recruitment in Benin, Côte d'Ivoire, Indonesia and Mali, restarted in Pakistan and Zambia, and hopes to open new study sites in Benin, Ethiopia, Guatemala, Indonesia, Kenya, Nepal and Niger.

This is truly fantastic and demonstrates the determination and support of all those involved in the study, and in particular our collaborators at sites.

Sponsored by the University of Oxford (UK) and led by the Bangkok-based Mahidol Oxford Tropical Medicine Research Unit (MORU), COPCOV (Chloroquine/ hydroxychloroquine prevention of coronavirus disease (COVID-19)) is funded by a grant by the COVID-19 Bill & Melinda Gates Foundation, Wellcome and MasterCard Therapeutics Accelerator.

However, timelines are tight if COPCOV is to answer the question as to whether chloroquine/ hydroxychloroquine prevents COVID-19. As the last-standing large prophylaxis RCT, the COPCOV study is in the unique position of being able to still give the answer definitively. Now, more than ever, with the end in sight, we need one last push from all!

Since COPCOV began recruitment in Thailand in April of 2020, the COVID-19 landscape has changed considerably. Vaccination has gone from a distant hope, to a reality for many but not all, and yet COVID-19 daily cases are some of the highest they have ever been worldwide. In addition, highly transmissible mutants have established themselves and overwhelmed countries which had previously dealt well with outbreaks. Mutants against which there is decreased vaccine efficacy are also here, and we should expect these to become more prevalent as vaccines apply selective pressure. Now, as before, effective chemotherapeutics could still be lifesaving to prevent and treat infections and maybe much more so, if we do see these mutants causing vaccine failures.

Recently it has been stated that the evidence suggests the drugs do not work. Most notably the WHO’s   A living guideline on drugs to prevent covid-19 stated that there was high certainty evidence that hydroxychloroquine does not prevent COVID-19.

This is wrong with large amounts of uncertainty in the effect which hydroxychloroquine may have in prevention. and with the effect estimate of currently published studies pointing towards moderate benefit. Truthfully, we still don’t know. While there is this uncertainty, and COVID-19 continues to infect people around the world, we must continue. We have responded to these articles, have a letter upcoming to The Lancet, pointing out their flaws, and have received strong support to continue from all those involved in the study and our excellent Trial Steering Committee and Data Safety and Management Board to continue.

Our thanks to everyone for their continued support and hard work, in what have been very challenging circumstances. Now more than ever, this study is needed, and with the recent increased recruitment, success is once again in our sights!

- Nick White and Will Schilling, COPCOV co-PIs.

For accessibility, we have posted a black & white version of the pie chart, and a table with all figures