This map shows the risk level of attending an event, given the event size and location.

You can reduce the risk that one case becomes many by wearing a mask, distancing, and gathering outdoors in smaller groups

The risk level is the estimated chance (0-100%) that at least 1 COVID-19 positive individual will be present at an event in a county, given the size of the event.

Based on seroprevalence data and increases in testing, by default we assume there are three times more cases than are being reported (3:1 ascertainment bias). In places with less testing availability, that bias may be higher. We are evaluating the inclusion of lower ascertainment biases based on increased testing.

The COVID-19 Event Risk Assessment Planning Tool is a collaborative project led by Prof. Joshua Weitz and Prof. Clio Andris at the Georgia Institute of Technology, along with researchers at the Applied Bioinformatics Laboratory and Stanford University, and powered by RStudio. Description of the method and analyses available at Nature Human Behaviour.