FRED Pennsylvania Measles Simulator

FRED (A Framework for Reconstructing Epidemiological Dynamics) is an agent-based modeling system for exploring the spatial and temporal patterns of epidemics. In this application for the Commonwealth of Pennsylvania, we used actual school vaccination data to realistically represent the infection risks by individual school. The model demonstrates the outcomes if a single student with measles attends school in a given county or metropolitan area. We also show how the number would change if the vaccination rate in all schools decreased.

It is important to note that we are showing the upper number of measles cases that could plausibly be expected to occur (occurring approximately 1 out of every 20 outbreaks) and we are not including the effect of any public health interventions that may occur after an outbreak starts (such as mass vaccination programs or increased isolation rates).

Infections amongst students for whom a vaccine has been refused are termed `refusal' cases; bystanders cases are infections among the rest of the population, including those for whom the vaccination failed (3% of people do not gain immunity after vaccination), those who are ineligible for vaccination due to medical conditions, and unvaccinated adults.

Measles by County

Use tabs below to view a decrease in vaccination coverage compared with current coverage.


Pennsylvania school vaccination coverage levels data retrieved from the publicly available data from the PA Department of Health.