Table 1 Participant inclusion and exclusion criteria

Index cases

• Provided a signed and dated informed consent form

• Aged 18 to < 80 years of age

• Confirmed SARS-CoV-2 diagnosis by PCR within 72 h of first treatment dose

• The first known diagnosis in the household

• Not currently enrolled in a clinical trial and agree to not take any other investigational treatments over the next 28 days

• Must plan to remain resident in the household during the study

• Lives in household with at least one other ‘treatment-eligible household contact

• Inability to take medications orally or by injection

• Known sensitivity/allergy to interferons or use of interferons for another indication

• Known adverse drug-drug interactions with any study drugs

• Malignancy

• Known clinical immune deficiency

• Pregnancy or unwillingness of female participant of childbearing age to use recognized methods of birth control/contraception during the trial period

• Retinopathy

• Known grade 4 or 5 chronic kidney or liver disease

• Known arrhythmias

• Known autoimmune disease or chronic inflammatory disease

• Chronic liver disease

• Hospitalization for depression in the last 3 months

• Current suicidal ideation

• Previous therapeutic use of IFN

Treatment eligible contact

• Provided a signed and dated informed consent form

• Aged 18 to < 80 years of age

• Not currently enrolled in a clinical trial and agree to not take any other investigational treatments over the next 28 days

• Must plan to remain resident in the household during the study

• No history of previously confirmed SARS-CoV-2 diagnosis

Treatment ineligible contact

• Provided a signed and dated informed consent form, parental informed consent, and assent if applicable

• Under 18 years OR ≥ 80 years of age OR aged 18 to < 80 years with any contraindication for IFN treatment listed in ‘exclusion criteria’

• Not currently enrolled in a clinical trial and agree to not take any other investigational treatments over the next 28 days

• Must plan to remain resident in the household during the study

• No history of previously confirmed SARS-CoV-2 diagnosis