For those wondering what mono is:
https://www.webmd.com/a-to-z-guides/understanding-mononucleosis-causes#1
Mononucleosis is an infectious illness that’s sometimes called mono or “the
kissing disease.” While you can get the virus that causes it through kissing, you can also get it in other ways like sharing drinks or utensils. It’s contagious, but you’re less likely to catch mono than other illnesses like the
common cold.
Mono isn’t usually a serious illness, but it can lead to complications that in some cases make the disease more dangerous. The symptoms of mono can be mild, but they can also become very severe. If that happens, you may not be able to take part in your normal, daily activities for up to several weeks.