17 May:
27 January: Regeneron Pharmaceuticals Inc has confirmed that their casirivimab and imdevimab antibody cocktail REGEN-COVTM successfully neutralised the two SARS-CoV-2 variants B.1.1.7 from the UK and B.1.351 from South Africa.
26 January: Regeneron Pharmaceuticals Inc has announced that results from an ongoing late stage clinical trial, its two-antibody cocktail REGEN-COV (casirivimab and imdevimab) was effective in preventing COVID-19 infections in those who are at a high risk of infection, such as being exposed to other infected people. Based on an analysis of 400 participants, a 100% reduction in symptomatic infection was observed, and an approximately 50% reduction in overall infection rates was seen within the first week. This indicates a potential application in "people who need immediate protection or respond poorly to vaccination."