The Institutional Review Board closed the study

The purpose of this study is to test the hypothesis that post-exposure prophylaxis with hydroxychloroquine will reduce the symptomatic secondary attack rate among household contacts of known or suspected COVID-19 patients.

COVID-19 is a massive threat to public health worldwide. Current estimates suggest that the novel coronavirus (SARS-CoV-2) is both highly contagious (estimated reproductive rate, 2-3) and five to fifty-fold more lethal than seasonal influenza (estimated mortality rate, 0.5-5%). Interventions to decrease the incidence and severity of COVID-19 are emergently needed.

Hydroxychloroquine (brand name, Plaquenil), an inexpensive anti-malarial medication with immunomodulatory effects, is a promising therapy for COVID-19. Chloroquine, a related compound with a less favorable toxicity profile, has shown benefit in clinical studies conducted in approximately one-hundred SARS-CoV-2 infected patients. In vitro, hydroxychloroquine has been recently shown to have greater efficacy against SARS-CoV-2 versus chloroquine.

Currently, there is no established post-exposure prophylaxis for persons at high risk of developing COVID-19. Hydroxychloroquine (brand name, Plaquenil), is a medicine that has been found to be effective against the novel coronavirus in some recent experiments. Previously, hydroxychloroquine has been safety used to prevent malaria or to treat autoimmune diseases.

This study will test if hydroxychloroquine may be used to prevent the development of COVID-19 symptoms in persons who live with an individual who has been diagnosed with COVID-19. If hydroxychloroquine is shown to reduce the risk of developing symptoms of COVID-19 among people at high risk of infection, this could help to reduce the morbidity and mortality of the COVID-19 epidemic.

This is a trial of hydroxychloroquine PEP among adult household contacts of COVID-19 patients in New York City (NYC). The trial will be initiated at NewYork-Presbyterian (NYP)/Columbia University Irving Medical Center (CUIMC).

Inclusion Criteria:

• Household contact of index case: currently residing in the same household as an individual evaluated at NYP via outpatient, emergency department (ED), or inpatient services who (1) test positive for COVID-19, or (2) are defined as suspected cases, or persons under investigations (PUI), by the treating physician.
• Willing to take study drug as directed for 5 days.

Exclusion Criteria:

• Age <18 years old
• Suspected or confirmed current COVID-19, defined as: (1) temperature > 38 Celsius; (2) cough; (3) shortness of breath; (4) sore throat; or, if available (not required), (5) positive confirmatory testing for COVID-19
• Suspected or confirmed convalescent COVID-19, defined as any of the above symptoms within the prior 4 weeks.
• Inability to take medications orally
• Inability to provide written consent
• Known sensitivity/allergy to hydroxychloroquine
• Current use of hydroxychloroquine for another indication
• Pregnancy
• Prior diagnosis of retinopathy
• Prior diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency
• Major comorbidities increasing risk of study drug including: i. Hematologic malignancy, ii. Advanced (stage 4-5) chronic kidney disease or dialysis therapy, iii. Known history of ventricular arrhythmias, iv. Current use of drugs that prolong the QT interval

2 out of 10 consented participants withdrew consent prior to initiating study intervention.

Due to the low number of participants per group, baseline characteristics are presented as one arm to protect the confidentiality of the participants.

Up to 14 days