Fig. 1: Reported protection and antibody concentration from RCTs of monoclonal antibodies in preventing COVID-19.

The efficacy at each time interval is shown in blue (points indicate observed efficacy, horizontal error bars indicate time interval and vertical error bars represent 95% CIs of efficacy). The antibody concentration is shown in black. a Antibody concentration (n = 1776 individuals) and efficacy data (n = 5172 individuals) for cilgavimab/tixagevimab was extracted from Levin et al.⁴ b Single administration of casirivimab/imdevimab data are a combination of data from O’Brien et al.⁶ and Herman et al.¹⁵ who report on the same clinical trial over different follow-up intervals. Efficacy data were reported weekly over the first four weeks in O’Brien et al. (diamonds) (n = 1505), and monthly for eight months in Herman et al. (circles) (n = 1683). Antibody concentration data was reported up to day 168 in O’Brien et al. (solid line, b n = 12), and modeling of the pharmacokinetic profile of the antibody concentration, reported in Herman et al., was used to inform the antibody concentration between 168 and 240 days (dashed line, b). c Isa et al.⁵ reported efficacy (n = 969) and in vivo concentration after repeated administration of 1.2 g of casirivimab/imdevimab every 4 weeks (n = 723). Hence, the antibody concentration did not decline as in the other studies. d The modeled concentration of adintrevimab after a single administration was extracted from the study by Schmidt et al.¹³. The efficacy of adintrevimab was reported both when the delta variant was dominant (circles) (n = 1267) and when Omicron variants BA.1 and BA.1.1 were dominant (triangles) (n = 378).