c19early.org COVID-19 treatment researchCOVID-19 treatments

Regeneron Reports Positive Interim Data with REGEN-COV™ Antibody Cocktail used as Passive Vaccine to Prevent COVID-19

Regeneron, Press Release, Jan 2021

Casirivimab/imdevimab for COVID-19

18th treatment shown to reduce risk in March 2021, now with p = 0.000095 from 34 studies, recognized in 52 countries. Efficacy is variant dependent.
Lower risk for hospitalization, progression, recovery, cases, and viral clearance.

No treatment is 100% effective.
Protocols combine treatments.

6,700+ studies · 220+ treatments

c19early.org
Meta-analysis
Interim results of REGEN-COV prophylaxis showing 100% prevention of symptomatic infection (8/223 placebo vs. 0/186 REGEN-COV), and approximately 50% lower overall rates of infection (symptomatic and asymptomatic) (23/223 placebo vs. 10/186 REGEN-COV).
Efficacy is variant dependent. In Vitro research suggests a lack of efficacy for many omicron variants1-7.
Standard of Care (SOC) for COVID-19 in the study country, the USA, is very poor with very low average efficacy for approved treatments8. Only expensive, high-profit treatments were approved for early treatment. Low-cost treatments were excluded, reducing the probability of early treatment due to access and cost barriers, and eliminating complementary and synergistic benefits seen with many low-cost treatments.
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OutcomeImprovementEffect · pTreatmentControl
risk of symptomatic case 93.6% lower · RR 0.06 · p = 0.009** 93.6% lowerRR 0.06p = 0.009** 0 of 186 (0.0%) 8 of 223 (3.6%) treatment 0 of 186 (0.0%), control 8 of 223 (3.6%)NNT 28continuity correction due to zero events
risk of case 47.9% lower · RR 0.52 · p = 0.07 47.9% lowerRR 0.52p = 0.07 10 of 186 (5.4%) 23 of 223 (10.3%) treatment 10 of 186 (5.4%), control 23 of 223 (10.3%)NNT 20

Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates. ** p < 0.01

Regeneron et al., 26 Jan 2021, Randomized Controlled Trial, USA, preprint, 1 author.
$0 $500 $1,000+ Efficacy vs. cost for COVID-19 treatment protocols c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Nigeria Taiwan Fiji Zambia Bosnia-Herzegovina Jordan Georgia Switzerland Dominican Republic Bolivia Côte d'Ivoire Eritrea Togo Bulgaria Greece Slovakia Iceland New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel Haiti North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy of treatments was very low.High-cost protocols reduce early treatment, andforgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
$0 $500 $1,000+ Efficacy vs. cost for COVID-19treatment protocols worldwide c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Taiwan Fiji Zambia Jordan Georgia Switzerland Dominican Rep. Bolivia Côte d'Ivoire Eritrea Togo Sri Lanka Bulgaria Greece Slovakia New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy was very low.High-cost protocols reduce early treatment,and forgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%