The idea is simple enough: When a neighborhood child contracted chicken pox, other parents would bring their children over to the infected child’s house to expose them to the disease (via SMH). Playdates were organized where kids were actually encouraged to share whistles and lollipops in hopes of infecting the uninfected.

And while pox parties proved popular over the decades, health professionals highly discouraged the practice back then and continue to do so in more modern times with the emergence of swine flu parties in 2009 (via The New York Times). While mostly benign, the highly contagious nature of chicken pox makes it deadly for infants, pregnant women, and those with compromised immune systems. But perhaps the best case against pox parties? The chicken pox virus isn’t the only thing that’s going to be shared at these events. As noted by InfectionControl.Tips, anything and everything — from the flu to the more deadly coronavirus — can be transmitted between people at these parties. And while a case of chicken pox is certainly uncomfortable, a bad case of influenza can be even deadlier to an infant.