Superspreader Epidemic

Heterogeneous Network SIR — Degree Distribution & Herd Immunity

Network

Epidemic Parameters

Statistics

R₀ (mean-field)
R₀ (network)
Herd immunity
Infected (peak)
Total attacked
Superspreaders

Theory

Heterogeneous mean-field:
R₀ = β/γ · ⟨k²⟩/⟨k⟩

Scale-free (power-law):
P(k) ~ k⁻ᵞ
⟨k²⟩ diverges for γ ≤ 3
→ R₀ → ∞, epidemic always spreads

Superspreaders: hubs (high-k nodes) disproportionately responsible for spread.