O’Brien MP, Forleo-Neto E, Musser BJ, et al. - In previously uninfected household contacts of cases diagnosed with SARS-CoV-2 infection, subcutaneous administration of REGEN-COV was identified to be linked with prevention of symptomatic Covid-19 and asymptomatic SARS-CoV-2 infection. Among the participants (household contacts of infected persons) who became infected, decreased duration of symptomatic disease and decreased duration of a high viral load were recorded in correlation with receiving REGEN-COV.

• Participants were randomly assigned to receive a total dose of 1,200 mg of REGEN-COV or matching placebo by means of subcutaneous injection.

• In the REGEN-COV group, 1.5% vs 7.8% in the placebo group had development of symptomatic SARS-CoV-2 infection.

• In weeks 2 to 4, 0.3% vs 3.6% had symptomatic SARS-CoV-2 infection in the REGEN-COV group and the placebo group, respectively.

• Among symptomatic infected participants, with REGEN-COV vs placebo, there was 2 weeks shorter median time to resolution of symptoms, and shorter duration of a high viral load (> 10⁴ copies per milliliter).