While the risk of catching an infection on an aircraft is typically lower than in a shopping center or an office environment, there are simple measures you can take to further reduce the risk when traveling: wear a mask, clean your hands regularly and check-in online to minimize contact at the airport.
And important to know: nearly all planes today have very sophisticated air filters which catch 99.99% of particles, including viruses like COVID-19. The cabin air is also replaced with new fresh air from outside every two to three minutes. This means that what you breathe onboard is the same quality as in an operating room at a hospital.
Finally, you must not travel when you are ill. Should you experience symptoms during or after a trip, seek medical attention. Most governments also provide clear instructions.