If you've been fully vaccinated against Covid-19, how safe is it for you to eat outdoors at a restaurant? Indoors? What about going to a grocery store, or flying on a plane? And what are the risks of these activities if you aren't vaccinated?
Microcovid.org attempts to calculate some of your Covid risks with a simple online calculator — which you can access here. Just tell it where you live, whether or not you're vaccinated (and if so, which vaccine you received), and which activity you're inquiring about (indoor/outdoor friend hangout, going to the market for 60 minutes, traveling by plane, etc).
For instance, living in Los Angeles and fully vaccinated, I'm still in the "moderate risk" category if I eat indoors with only two people nearby (at least 6 feet away). That turns to "high risk" if three people are nearby, and "very high risk," if there are nine people or more in the room. It never reached the most hazardous level — "dangerously high risk" — I suppose because I've been vaccinated.
If I eat outdoors, my risk is low until 15 people sit nearby, and then the risk goes up to moderate.
Started by a "pandemic pod" of friends in May 2020, the group "incorporated dozens of volunteer collaborators over the next few months including mathematicians, data scientists and a primary care clinician" to create their microCOVID calculator, according to Smithsonian Magazine. It has recently been updated to reflect the "increased" risks due to the Delta variant.
Of course, the "calculations" are just rough estimates.
Being within a certain range on the risk budget might seem like guaranteed safety, but that doesn't mean your risk of infection is zero, warns F. Perry Wilson, an epidemiologist at Yale University, who is not involved in the project. Risk budgeting tools like this one can also give "a false sense of security," he says, and "might give people sort of permission to behave in ways that might put them in more danger than they appreciate."
Wilson is concerned about potentially wide error margins and says he is hesitant to put too much stock in a single number. Still, Wilson suggests using the tool to get a rough idea about your risk, while remembering that the studies and data the calculator is based on are still early and change often. The site's White Paper outlines the specific peer-reviewed studies, contract tracing data and aerosol models used in the calculator, which are updated as new research emerges.
The microCOVID Project is one of many Covid-19 risk assessment tools aimed at helping the public make evidence-based decisions about their health. Mathematica's 19 and Me calculator is a credit-score style tool that lets users input their location, age, health concerns and behaviors before churning out a score that reflects risk of infection. Another freely-available tool is MyCOVIDRisk, a questionnaire-based web app that assesses the riskiness of a given scenario.
Here's a video on how the calculator works: