Trial (Author, Year, study country)

Population

Intervention

Comparator

Outcome

Timing Maximum time from exposure to intervention

Study Design

Boulware 2020

(n = 821)

United States and Canada

Adults > 18 yrs post household or occupational exposure to confirmed COVID-19

Post Exposure prophylaxis

Hydroxychloroquine 800 mg once, followed by 600 mg in 6-8 hrs followed by 600 mg once daily for 4 additional days

Placebo

Primary: PCR confirmed or probable COVID-19

(self reported)

Up to 6 days

Randomised double blind placebo controlled

Mitja 2020

(n = 2,134)

Spain

Adults > 18 yrs healthcare worker^*,nursing home residents, household post exposure to confirmed COVID-19

Post-exposure Prophylaxis

Hydroxychloroquine 800 mg once, and then 400 mg daily for 6 days

No specific therapy

Primary: PCR-confirmed symptomatic Covid-19 within 14 days

Up to 7 days

Open label cluster-randomised

Rajasingham 2020

(n = 1,483) United States and Canada

Adults > 18 yrs healthcare worker with ongoing exposure to persons with SARS-CoV-2

Pre-Exposure Prophylaxis

Hydroxychloroquine 400 mg loading dose followed by 400 mg in 6-8 hrs followed by 400 mg once or twice weekly for 12 weeks

Placebo

Primary: PCR confirmed or probable Covid-19

(self reported)

Randomised double-blind, placebo-controlled

Abella 2020

(n = 125) United States

Adults >18 yrs healthcare workers with ongoing exposure to persons with COVID-19

Pre-exposure Prophylaxis

Hydroxychloroquine 600 mg daily for 8 weeks

Placebo

Primary: Incidence of SARS-CoV-2 infection as determined by a nasopharyngeal swab during the 8 weeks of treatment

(PCR confirmed COVID-19)

Randomised double blind placebo controlled