Getting COVID-19 today is much less scary and more common than it was three years ago. By now, many people have had it not just once, but two, three, or even more times. Most of the time, repeat infections aren’t as severe as they were the first time, leading to a sense of complacency about getting COVID-19 over and over.

But reinfections aren’t harmless. As cases continue to rise and more variants arrive on the scene, infectious-disease experts are warning that repeat infections could have cumulative, lasting effects.

“There is some early evidence starting to show that if you had COVID-19, there can be all sorts of problems after getting infected” and reinfected, says Dr. Robert Murphy, professor of medicine and executive director of the Havey Institute for Global Heal…