Estimating Your Chances Of Being Exposed To Omicron

The figures below are all estimates based on a back-of-the-napkin calculation. I'm also using numbers from across the United States. As a result, I'm ignoring the fact that some states have a lot more COVID cases and lower vaccination rates than others for the sake of simplicity, and assume that infected people are evenly distributed across the country (in reality, people who live in dense, unvaccinated urban areas are at much higher risk).

According to the New York Times, there were 387Knew cases on January 1st. Daily new cases have exceeded 300,000 since December 29, 2021. Because not everyone who gets sick with COVID gets tested or reports it, reported cases often underestimate the total number of infections. Let's say the true number of persons that catch COVID each day and subsequently develop symptoms is 400,000. That's a lot, but things are about to get a lot worse. According to this article (and the research it cites), 40% of COVID cases are asymptomatic, implying that the true number of infections is roughly 667K (400K / 0.6).

COVID-infected people are contagious for around 2 days before symptoms appear, according to this study. This suggests that there is at least two days' worth of people marching around with COVID and the ability to infect others but no symptoms. Assuming that most people isolate once symptoms appear (and they are no longer a threat to infect), we may estimate that there are around 2.67 million people (667K * 4) walking around in the United States at any given time who could potentially infect you.

You could be infected by one out of every 123 persons.

The United States has a population of around 330 million people. This means that 0.8 percent of the population in the United States is contagious and active right now – in other words, 1 out of every 123 people could infect you.

Let's see how likely it is to come into contact with an infected person at various locations.

Visiting the supermarket

Assuming a typical-sized supermarket and the capacity to socially remove yourself while shopping, I estimate that you are only within the infection range ( 6 feet) of 8 people throughout your visit (the vegetable and fruits section at Whole Foods gets pretty cluttered). A random person you meet has a 99.2 percent chance of not having COVID (1 - 0.8 percent ). As a result, the likelihood that none of them have COVID is 0.9928 = 0.937. In other words, a regular supermarket trip has a 6.3 percent probability of exposing you to COVID (so wear your mask and sanitize!).

This may also be an underestimation of the likelihood. Keep in mind that other people are handling the groceries, and you can come into contact with a box of cereal that has been touched by someone who has COVID.

Visiting a nightclub
I wouldn't go partying in the middle of a pandemic, but if you insist, let's figure out your chances of getting infected. Around 200 people can fit into a regular club (the crammed variety, not the glitzy Vegas kind). If you stay the entire time as others arrive and go, there will have been around 600 people inside the club by the time you finally are ready to leave.

While dancing, making your way to the restroom and jostling for beverages, you'll have likely come into contact with a fifth of those 600 people (120 people). That's a lot of people – there's only a 38 percent probability (0.992120) that all 120 don't have COVID, which indicates you've had close contact with an infected person 62 percent of the time (feels like I am writing about a zombie movie).

Granted, this does not imply that you have a 62 percent probability of contracting COVID. If you're fully vaccinated, there's a good chance you'll prevent infection or, at the very least, have reduced symptoms if you do get it. Still, if you go dancing or bar-hopping these days, you're essentially playing with fire.

Avoid crowded places, put on a mask, and get your flu shot.

It's now difficult to prevent COVID exposure, thanks to Delta and now Omicron. Even if you just hide and order DoorDash, the sheer number of infections out there now means that each DoorDash order has a 2.4 percent chance (0.9923, assuming that a cook, to-go packer, and delivery person handle your order) of exposing you to COVID. If you keep changing restaurants (and infections continue high), you'll have a 50% chance of contracting COVID from your delivered meal after 28 days!

Friends, be safe out there – my estimated figures sound terrifying. But it's better to know than to hope that things aren't as horrible as they appear. Knowing allows us to make sensible decisions, ensuring that we all make it safely to the other side.