Nearly half the population of the US and about a third of people around the world are now under some form of quarantine as part of the effort to fight the spread of the COVID-19 pandemic.

With instructions to remain at home and maintain physical distance between themselves and others—outside of completing essential tasks—people have been driven more and more to the warm embrace of the Internet. With a pandemic spreading outside, digital forms of socializing that avoid the risk of spreading COVID-19 are more essential than ever. But in the case of Instagram, the newest meme challenge to take over the platform shares some things in common with the coronavirus—it’s been going viral in more ways than one.

Compared to other viral trends that people simply join for fun, or because a friend called them out to participate, Instagram posts with the hashtag #untiltomorrow work more like an infectious disease. An embarrassing image posted under the hashtag is the most obvious symptom, and it carries with it the contagion. If you interact with one of these posts in the 24 hour period during which they remain active, you will be exposed to the infection, and it won’t be long before you’re likely to start infecting others.

It works like this: One of your friends will post a goofy, unflattering, or just generally embarrassing photo, tagging one person and including the hashtag #untiltomorrow. After 24 hours they will delete that post, but if you are foolish enough to like the image before that time is up, you will receive a message from your friend explaining that it’s your turn. You will be conscripted to post an embarrassing image of yourself with the infectious hashtag and to tag the person who infected you.

So far the #untiltomorrow has been spreading quickly, with over 550,000 active posts as of Thursday morning—compared to 350,000 on Wednesday night. While many people will have a natural immunity to this new contagion (otherwise known as indifference), for the rest of us our only hope is to spread clear and correct information about the danger and to avoid contact with the infected. Maybe stay off of Instagram for a while. There are lots of other ways to spend your time: Go outside, go see a movie, do something with your friends, or…oh wait.

If #untiltomorrow continues to follow the patterns of an infectious disease, it’s going to get even more popular in coming days. Of course there are a number of important distinctions between the challenge and an actual infectious disease. For a start, its incubation period is much shorter than COVID-19, and the signs of infection should be immediately recognizable to anyone who has been informed—not to mention it’s not going to kill anyone. Still, it will be interesting to see if the hashtag takes over all of Instagram, or if the spread of information will begin to “flatten the curve,” causing the challenge to slowly disappear.

While the stakes are nonexistent next to the millions of lives at risk from the coronavirus, the trajectory of the #untiltomorrow challenge should be a reminder to everyone of how quickly infections can spread and to be careful not to contribute to the COVID-19 pandemic.