Unlikelihood of benefit based on other studies.

This is a prospective, double-blind, randomized, placebo-controlled study in two distinct cohorts to evaluate the efficacy and safety of hydroxychloroquine in the prevention of COVID-19 infection.

Inclusion Criteria:

Inclusion Criteria Cohort A:

• ≥ 18 years old

• Employee of healthcare organization in South Dakota or Sanford Health employee in any location and with exposure to a person with COVID-19 within the last 5 days

  • Occupational exposure as determined by the participant's employee health department (i.e. not wearing the proper Personal Protective Equipment (PPE))
  • Criteria according to Center for Disease Control (CDC) guidelines
  • Community exposure (within 6 feet for at least 15 minutes)

• No current symptoms attributable to COVID-19, per HCW report (fever, cough, difficulty breathing, sore throat)

• No prior COVID-19 positive diagnosis (eligible if previous testing is negative and meets all other inclusion and exclusion)

• Ability to provide informed consent

Inclusion Criteria - Cohort B

• ≥ 18 years old

• High-risk person who had close contact (i.e. within 6 feet for at least 15 minutes) with a COVID-19 positive person within the last 5 days and is a South Dakota resident or high-risk person with close household contact of a COVID-19 positive Sanford employee

• High-risk person defined by:

• Age 18-44 with 2 or more comorbidities listed below

• Age 45-79 with any comorbid condition listed below

• Age 80 and above (regardless of comorbid conditions)

• Co-morbid list

  • Congestive Heart Failure (CHF)
  • Chronic lung disease (Includes any of the following: asthma, chronic obstructive pulmonary disease, emphysema)
  • Solid organ transplant or immunosuppression (Defined as an outpatient prescription of greater than 10 mg/day of prednisone or equivalent, use of chemotherapy, or use of immunosuppressive agents for solid organ transplant or for an autoimmune disease.)
  • Chronic Kidney Disease or End Stage Renal Disease
  • Diabetes mellitus
  • Cardiovascular disease/Hypertension
  • Smoking/Vaping (currently using or history of using in the past 1 year)
  • Obesity (calculated by height and weight per participant report)
  • Hyperlipidemia

• No current symptoms attributable to COVID-19

• No prior COVID-19 positive diagnosis (eligible if previous testing is negative and meets all other inclusion and exclusion)

• Ability to provide informed consent

• Confirmed review of concomitant medications (with emphasis on cardiac medications)

Exclusion Criteria Cohort A & B:

• Known allergy to hydroxychloroquine or quinine
• Known history of long QT syndrome
• Known history of arrhythmia or dysrhythmia
• Known current QTc >500 ms
• Known G6PD deficiency
• Known history of hypoglycemia
• Pregnant or Nursing by patient history
• Use of any of the following concomitant medications: See Appendix D for Exclusion medication list
• Concurrent diagnosis of dermatitis, porphyria, or psoriasis
• History of chronic liver disease, including cirrhosis and/or diagnosis of hepatitis (infectious, idiopathic, or immune)
• History of chronic kidney disease
• Pre-existing retinopathy
• Already taking hydroxychloroquine
• Any condition or medication in the opinion of the investigator that would prohibit the use of hydroxychloroquine
• Enrollment in another clinical with investigational drug or device
• Inability to swallow pills
• Adults unable to provide informed consent

No subjects or data analyzed. Study was closed to enrollment before analysis.

Adverse events were collected from Day 1 of treatment through 12 months after day 1.

No enrollments to Cohort B. No enrollments to Cohort A (Healthcare Worker-Placebo).

CT CAE criteria was used for the 1 participant on Cohort A (Healthcare Worker-Hydroxychloroquine)