Inclusion/Exclusion Criteria

Randomised controlled trials (published up to July 2021) comparing efficacy of IFN-β to that of standard of care in terms of mortality, LOHS, and/or time to clinical improvement, were included. Studies with significant inconsistency between experimental and control groups and studies with use of IFN-beta in experimental as well as in control study arms, were excluded from meta-analysis (Table 1).

Characteristics of included studies

1^o Viral negativity

2^o Time to resolution of symptoms,

duration of hospitalisation

Mortality

1^o Time to clinical improvement

2^o Discharge from hospital

1^o Time to clinical improvement,

2^o Normalisation of inflammatory markers, improvement in oxygen saturation

Inhalation, 8 MIU (0.25 mg) twice a

day was given for 5 days

1^o Time to clinical improvement

2^o Percentage

of patients discharged, duration of hospitalisation

1^o Time to clinical improvement

2^o Percentage of patients discharged, duration of hospitalisation

1.IFN-β1a + SOC^d

2. IFN-β1b + SOC^d

1^o Time to clinical improvement

2^o Mortality, duration of hospitalisation

1. IFN-β1a: SC, 12,000 IU/44 mcg on days 1, 3, 6

2. IFN-β1b: SC, 8 MIU on Days 1, 3, 6

1^o Mortality

2^o Initiation of mechanical ventilation, duration of hospitalisation

SC, 44 mcg, on Days 1, 3 & 6

IV, 10 mcg daily for 6 days

1^o Time to clinical improvement

2^o Mortality

SC, 88 mcg (24 MIU) on days 1, 3, 6

SC, 44 mcg (12 MIU) on Days 1, 3, 6

1^o Primary outcome, 2^o Secondary outcome

ATV/r atazanavir and ritonavir combination, COVID-19 Coronavirus disease 2019, HCQ hydroxychloroquine, IFN interferon, IU International Unit, IV intravenous, LPV/r lopinavir and ritonavir combination, mcg microgram, MIU million/mega International Unit, RCT randomized controlled trial, SC subcutaneous, SOC standard of care

^aLPV/r[10]

^bLocal standard of care[16]

^c+ LPV/r or ATV/r + HCQ for 7–10 days [18, 19]

^dLPV/r + HCQ single dose[20]