Fight Off Viruses

How to effectively strengthen your immune system

- Mike Zimmerman

One thing that the COVID-19 pandemic has made clear is that some people who get the virus don’t suffer much, while others become very sick indeed. And while the elderly have been particularly hard hit, some do survive—even centenarians. As for younger people, whose immune systems are supposed to be more robust, many have nevertheless died of it. So, what factors give some people a stronger immune system than others, regardless of age? What does it mean if, for example, your partner or child gets sick, and you don’t—or vice versa?

We know that our immune-system function slowly declines with age. Just like when you see a photo of yourself from ten years ago versus one taken this afternoon, you see changes in your face, skin, and hair colour. It takes time. “Same process with your immune system,” says Dr Insoo Kang, associate professor of medicine and director of allergy and immunology at the Yale School of Medicine.

Kang has been studying human ageing for 20 years. “Immune cells, especially CD8+ T cells [a type of white blood cell], change with ageing. We see fewer of those CD8+ T cells, which are needed to recognise newly emerging microorganisms like the COVID-19 virus. It happens to everyone on some level, just not at the same rate.”