Study to ask: Does antimalarial drug prevent COVID-19?

The benefits of hydroxychloroquine being investigated in multi-site clinical trial launching in April.

Media Contact: Bobbi Nodell -, 206.543.7129

Researchers are investigating whether hydroxychloroquine, a commonly used anti-malarial and autoimmune-disease treatment, can prevent COVID-19.

A multi-site clinical trial, led by the University of Washington School of Medicine in collaboration with New York University Grossman School of Medicine, aims to definitively determine whether hydroxychloroquine can prevent transmission in people exposed to the virus.

"We currently don’t know if hydroxychloroquine works, but we will learn in as short a timeframe as possible what the outcome is,” said principal investigator Ruanne Barnabas, associate professor of global health in the University of Washington schools of Medicine and Public Health. 

Her team is starting to enroll 2,000 participants referred by physicians in six sites who are close contacts of persons with confirmed or pending COVID-19 diagnoses. 

Participants will be randomly assigned to take hydroxychloroquine or a placebo over two weeks, and nasal swab samples will be collected and tested daily to confirm new COVID-19 infections across the two groups. Sandoz, a Novartis division, has donated the hydroxychloroquine doses needed to conduct the study.

The trial is slated to run for eight weeks and, if all goes well, results are expected in summer.

"Our goal is to stop transmission of COVID-19 in the community,” Barnabas said.

If the drug does not work, she said investigators can put their time and energy into other prevention and treatment interventions. 

"Currently, there is no proven way to prevent COVID-19 after being exposed," says Anna Bershteyn, assistant professor of population health at NYU and co-principal investigator on the study. "If hydroxychloroquine provides protection, then it could be an essential tool for fighting this pandemic. If it doesn't, then people should avoid unnecessary risks from taking the drug.”

The $9.5 million trial looking at post-exposure preventive therapy for COVID-19 is part of a $125 million initiative launched by the Bill & Melinda Gates Foundation, Wellcome Trust, and Mastercard to speed development and access to therapies against COVID-19. The three organizations are partners in the COVID-19 Therapeutics Accelerator. The hydroxychloroquine trial is one of three grants announced Monday by the accelerator. 

Hydroxychloroquine is a medication that has been used since the early 1950s. It’s used to prevent malaria and autoimmune diseases like rheumatoid arthritis and lupus.  The medication is hypothesized to work by preventing the virus from entering the cell.

All participants in the trial will be screened carefully to make sure they do not have an allergy to the medication. They will also be monitored through telehealth consultations.

Barnabas is a faculty member at the UW's International Clinical Research Center, which ran one of the large multi-site trials in Africa showing the efficacy of Truvada in preventing HIV transmission. She just finished a multi-site trial in South Africa and Uganda showing the benefit of using mobile vans to deliver treatment to people living with HIV. 

In this trial, participants will be doing self-collection of specimens and they won’t be going to a clinic, which will preserve clinical space for people who are ill. Barnabas said the idea for the trial implementation came from providing community-based HIV care.

Data from the trial will be shared via the open-access COVID-19 Therapeutics Accelerator website to ensure scientists everywhere can benefit from its findings. 

To learn more about the University of Washington's trial, please visit the study’s web page.

In related news, the University of Washington School of Medicine is one of 37 sites enrolling 2,000 outpatients testing positive for COVID-19 to see whether a treatment combining a low dose of hydroxychloroquine and azithromycin can prevent hospitalization and death;  Dr. Ann Collier, professor of medicine in the Division of Allergy and Infectious Diseases at the Univerisity of Washington School of Medicine, is leading the NIH-funded study. Christine Johnston, associate professor of medicine in the Division of Allergy and infectious diseases is leading a smaller hydroxychloroquine and azithromicin treatment trial.

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