Gotto remember how you catch it and how much viral load you get can increase severity. If you are chatting in the open to someone who has it. You aren't going to inhale that many viruses. They will take time to replicate giving your immune system time to build defenses. Spending hours in a room with someone infected, kissing, sharing drinks. You are going to get a lot more, that will replicate enter cells... your immune dystem czn be overwhelmed and go nuts. Cytokine storm attacking healthy cells and tearing holes in lungs.
Or just get vaccinated.
Or just get vaccinated.