SeroJump WebAssembly Widget

Interactive web application for simulating individual antibody trajectories and fitting them using serojump-style reversible-jump MCMC.

Features

• Individual Trajectory Simulation: Simulate 10 individuals with mixed infection histories
• Antibody Kinetics: Model IgG titre dynamics with infection events
• Real-time RJ-MCMC: Bayesian inference for infection probabilities
• Interactive Visualization: Real-time parameter traces and trajectory plots
• WebAssembly Performance: High-speed C++ core compiled to WASM

Architecture

Data Model

struct Individual {
    int id;
    vector<double> sample_times;     // when samples were taken
    vector<double> titre_values;     // observed IgG titres
    vector<double> infection_times;  // true infection times (for simulation)
    double infection_prob;           // fitted infection probability
};

Antibody Kinetics

• Pre-infection: Baseline titre with noise
• Post-infection: Exponential rise then decay
• Function: titre = baseline + boost * exp(-decay * (t - t_inf)) for t > t_inf

RJ-MCMC Components

1. Parameter updates: baseline titre, boost, decay, noise
2. Infection time updates: continuous time proposals
3. Model selection: infected vs uninfected states
4. Acceptance criteria: Metropolis-Hastings with jacobians

Quick Start

./build.sh
./start.sh

Visit http://localhost:2020 to use the widget.