Spread Model
Explore how contact and recovery shape a fictional outbreak.
A simplified teaching model of a fictional disease. This is not medical advice.
Day 0
Observed peak infectious count: 1 (Day 0).
How to play
Run automatically or advance one day. Changing settings repeats the same random sequence. Circles are susceptible, crosses infectious, and squares immune. The initial preview runs up to 40 days. The graph plots susceptible, infectious and immune people and stops at zero infections or 180 days.
Learn more
Contacts are sampled randomly among 100 people; dot positions do not determine contact. Transmission probability is 0.2 per contact and daily recovery probability is the reciprocal of mean recovery days. Initial immunity is complete and permanent; recovered people cannot be reinfected. This cannot predict real diseases or vaccines.