Network SEIR Epidemic
Contact heterogeneity, herd immunity threshold, epidemic dynamics
Transmission β
0.10
Incubation σ⁻¹
5d
Recovery γ⁻¹
7d
Network k̄
5
Vaccination %
0
%
Start
Reset Network
Seed Outbreak
●
S Susceptible
●
E Exposed
●
I Infectious
●
R Recovered
●
V Vaccinated
R₀ = —
Infected: 0
Immune: 0%
SEIR on scale-free network (Barabási-Albert). High-degree nodes (hubs) accelerate spread. Herd immunity threshold: p_c = 1 − 1/R₀ (homogeneous). For heterogeneous networks: p_c = 1 − ⟨k⟩/⟨k²⟩·(1/R₀). Click a node to infect it.