You don’t get sick on airplanes any more than anywhere else. Really, you don’t.
If you think this is preposterous or even dangerous to suggest during a pandemic, consider this fact: The ventilation system requirements for airplanes meet the levels recommended by the Centers for Disease Control and Prevention for use with covid-19 patients in airborne infection isolation rooms.
Before we go any further, let’s make one thing clear: Airplanes are certainly vectors of disease, efficiently transporting infectious people around countries and the globe. This is obviously critical in terms of outbreak control for covid-19. But the fact that airplanes help spread disease across geographies does not mean that you are necessarily at risk during flight. There are fairly simple things you can do, if you do need to travel, to reduce the odds of getting sick.