About the Study

  • The purpose of this study is to understand if taking hydroxychloroquine (HCQ) OR HCQ plus azithromycin may be used to help treat people infected with early COVID-19 infection.
  • We will study these medications in people who are well enough to be treated in their homes.
  • We will study the medication in people who are at increased risk for developing complications of SARS-CoV-2 infection, and also people who do not have identified risk factors for more severe infection.
  • If you choose to be in the study, you will be assigned by chance to either take HCQ + folic acid, HCQ + azithromycin, or vitamin C + folic acid for 10 days.
  • We will ask you to fill out two daily surveys, take your vitals and take a nasal swab every day for 14 days, and then again 21 and 28 days after you start.

Why these drugs?

HCQ is currently FDA approved to treat malaria and autoimmune diseases. We don’t know if HCQ is an effective early treatment for COVID-19. In small studies conducted in a lab, scientists observed that cells that were treated with HCQ blocked coronaviruses (including SARS-CoV-2) from entering the cells and infecting them. It may be possible that taking HCQ soon after infection prevents the virus from replicating and that this can decrease disease severity and hospitalization.

Azithromycin is an antibiotic FDA approved to treat pneumonia and sinus infections. Azithromycin has shown antiviral activity in the lab against Zika, Ebola, and rhinoviruses. It may be possible that taking Azithromycin soon after infection prevents the virus from replicating and that this can decrease disease severity and hospitalization.

Sample size

The study will enroll 495 participants considered to be high risk and 135 considered to be low risk, for a total of 620 participants. Participants will be recruited from 6 sites around the country.


There will be twenty-eight days of clinical follow-up per participant.
Each site plans to enroll participants for 4 weeks.

This study is led by International Clinical Research Center/Department of Global Health, University of Washington, along with the UW Virology Research Clinic, Cook County Health/RMR CORE Center – Chicago, and SUNY. This study is part of a $125 million initiative launched by the Bill & Melinda Gates Foundation, Welcome Trust, and Mastercard to speed development and access to therapies against the respiratory virus that has spread throughout the world. The three organizations are partners in the COVID-19 Therapeutics Accelerator.