biology

Epidemiology & Disease Dynamics

Model how diseases spread through populations — from herd immunity thresholds and contact tracing networks to vaccine trial design, R₀ dynamics, and epidemic curve flattening.

epidemiologyherd immunityR0vaccinecontact tracingepidemic curve

Epidemiology is the study of how diseases distribute and propagate through human populations. At its core lies the basic reproduction number R₀ — the average number of secondary infections produced by a single infected individual in a fully susceptible population. When R₀ exceeds 1, an epidemic grows exponentially; below 1, it fades away. Understanding these dynamics is essential for designing effective public health interventions.

These simulations let you experiment with the levers of epidemic control. Calculate herd immunity thresholds for different diseases, trace contacts through social networks, design vaccine trials with proper statistical power, manipulate R₀ through interventions, and observe how different strategies flatten the epidemic curve to protect healthcare capacity.

5 interactive simulations

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Contact Tracing Network Simulation

Watch a disease spread through a social network and see how contact tracing identifies and isolates infectious individuals to break transmission chains

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Epidemic Curve Flattening Strategies

Model SIR epidemic dynamics and observe how timing and intensity of interventions flatten the curve to keep cases below healthcare capacity

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Herd Immunity Threshold Calculator

Calculate the herd immunity threshold for any disease — visualize how vaccination coverage protects unvaccinated individuals through population-level immunity

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Basic Reproduction Number R₀ Dynamics

Manipulate the basic reproduction number R₀ and observe how interventions like masking, distancing, and vaccination drive the effective reproduction number below 1

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Vaccine Efficacy & Trial Design

Design a vaccine clinical trial — set sample sizes, observe attack rates in treatment and control groups, and calculate efficacy with confidence intervals