Spatial SIR Epidemic

Click the grid to seed infection — watch wavefronts spread

Susceptible
Infected
Recovered
Click to seed infection
Spatial SIR model
Each cell: S→I with rate β per infected neighbor, I→R with rate γ.

Wave speed ∝ √(β·D) where D is diffusion. Above epidemic threshold R₀>1 waves propagate; vaccination reduces effective R₀.

Click on grid to seed infection anywhere.