Effective Reproduction Number R(t)
Cori method: R(t) estimated from epidemic curve using serial interval distribution
Daily cases
R(t) estimate
95% CI
R = 1 threshold
R₀ phase 1:
2.5
R₀ phase 2:
0.7
Intervention day:
40
Serial interval μ:
5
d
Re-simulate
Cori method:
R(t) = [Σᵢ Iₜ] / [Σᵢ Σₛ Iₜ₋ₛ w(s)] where w(s) is the serial interval distribution (gamma). R(t) > 1 → epidemic growing; R(t) < 1 → declining. Confidence intervals from gamma posterior (Bayesian Cori).