c19early.org COVID-19 treatment researchCOVID-19 treatments

Hydroxychloroquine in the Prevention of COVID-19 Infection in Healthcare Workers

McCullough et al., NCT04333225, Aug 2021
Pre-exposure prophylaxisProspective · 221 patients · USA
HCQ for COVID-19
McCullough et al. NCT04333225 · August 2021
Outcome
Improvement
Relative Risk · 95% CI
Case
52%0.48 · 0.27–0.87
00.511.52+
← HCQ reduces riskIncreased risk →
Fewer cases with HCQ
p = 0.012

HCQ for COVID-19

1st treatment shown to reduce risk in March 2020, now with p < 0.0000000001 from 426 studies, used in 59 countries.
Lower risk for mortality, hospitalization, progression, recovery, cases, and viral clearance.

No treatment is 100% effective.
Protocols combine treatments.

6,700+ studies · 220+ treatments

c19early.org
Meta-analysis
Prospective study with 221 healthcare workers, showing lower risk of COVID-19 with HCQ prophylaxis.
Standard of Care (SOC) for COVID-19 in the study country, the USA, is very poor with very low average efficacy for approved treatments1. 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 case 51.7% lower · RR 0.48 · p = 0.01* 51.7% lowerRR 0.48p = 0.01* 13 of 101 (12.9%) 32 of 120 (26.7%) treatment 13 of 101 (12.9%), control 32 of 120 (26.7%)NNT 7.2

Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates. * p < 0.05

McCullough et al., 20 Aug 2021, prospective, 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%