WOLFRAM

Life Sciences

Use System Modeler for modeling and analysis throughout drug discovery, development, clinical trials, and manufacturing. The flexible environment supports application areas such as systems biology, bioinformatics, and more.

Uncertainties in Herd Immunity

Exploring the dynamics of the Susceptible-Infected-Recovered (SIR) model is crucial for pandemic control. It all starts with the well-known concept of R0, reproduction number, which measures disease contagion. Analyzing R0, including its potential distribution models like Gaussian or uniform, plays a significant role in informing effective public health responses, vaccination strategies and policy development.

Modeling Susceptible-Infected-Recovered Population Dynamics

An SIR model offers meaningful insights for herd immunity, illustrating the intricate balance between susceptible, infected and recovered populations under a vaccination program.

The SIR model flow of disease progression with vaccination, showing transitions from susceptible to infected to recovered, with vaccinations enabling direct recovery without infection.

Shifts in Epidemic Trends

Let’s examine a detailed depiction of the variations in the susceptible, infected and recovered populations over 200 days with a daily vaccination rate of 0.5%. This visual analysis is instrumental in tracing the course of an epidemic, providing a clear perspective on the effectiveness of current health measures and highlighting the necessity for adaptive strategies.

An SIR model simulation with a 20% uniformly distributed uncertainty in the R0 depicts the median and range of susceptible, infected and recovered individuals over time. As seen, the peak time and date of infectious individuals are highly dependent on the R0.
Run an uncertainty analysis easily using the SystemModelUncertaintyPlot function.

Studying Gaussian-Distributed Uncertainties in the System

Alongside the R0, the average infectious time plays a crucial role in herd immunity dynamics. In this case, uncertainties are assumed to follow a Gaussian distribution, with a 20% variance in both the reproduction number and the mean infectious period.

Epidemic curves with the upper graph modeling a mean infection duration of 5 days and a variance of 1 day, and the lower graph with a mean R0 of 2.5 and a variance of 0.5, revealing different disease spread dynamics.

Vaccine Efficacy and Health Care Limits

Utilizing the SystemModelUncertaintyPlot function to analyze uncertainty in vaccine effectiveness is key to optimal vaccine selection and resource allocation. This approach underscores the vital impact of vaccine efficacy and health care capacity on infection management.

Influence of 20% uncertainty in vaccine efficacy and health care capacity usage suggests it is likely that health care capacity will not meet the demand.

Uncertainty Analysis in Herd Immunity