• Statistically significant improvements are seen for mortality, hospitalization, progression, recovery, cases, and viral clearance. 17 studies from 12 independent teams in 4 different countries show statistically significant improvements in isolation (7 for the most serious outcome).
• Meta analysis using the most serious outcome reported shows 56% [37‑69%] improvement. Results are similar for Randomized Controlled Trials, similar after exclusions, and slightly worse for peer-reviewed studies. Results are consistent with early treatment being more effective than late treatment.
• Results are robust — in exclusion sensitivity analysis 13 of 24 studies must be excluded to avoid finding statistically significant efficacy in pooled analysis.
• Efficacy is variant dependent. In Vitro
studies suggest a lack of efficacy for omicron [Liu, Sheward, Tatham, VanBlargan]. Monoclonal antibody use with variants can be associated with prolonged viral loads, clinical deterioration, and immune escape [Choudhary].
• No treatment, vaccine, or intervention is 100% effective and available. All practical, effective, and safe means should be used based on risk/benefit analysis. Multiple treatments are typically used in combination, and other treatments may be more effective. Only 29% of casirivimab/imdevimab studies show zero events with treatment.
• All data to reproduce this paper and sources are in the appendix.
Covid Analysis et al., 20 Sep 2022, preprint, 1 author.