A way to describe those irresponsible and unwise people who do believe they are resistant/immune to the virus by not wearing masks, staying in quarantine or take any necessary precautions for their own sake and others.
Stay safe people!
Anna: Hey Josh, im going out see ya in a few hours.
Josh: Anna..no what are you doing? You know we are in the middle of a pandemic right? We need to take all the necessary precautions! Jesus your not even wearing a mask..
Anna: oh stop worrying... you are so in your head!
Josh: because this is a serious matter! Your not covid-19 resistant!