Some People’s Bodies Learn to Live With Covid-19

The new science of ‘disease tolerance’ could open the door to revolutionary Covid-19 treatments

Illustration: Cha Pornea

One of the tragic ironies of disease-causing infections is that, in many cases, it’s not the offending virus or bacteria that kills. At least not directly. It’s the immune system’s response to a pathogen — or, more accurately, its over-response — that ultimately causes internal destruction and death.

The novel coronavirus seems to play by these rules. One of the defining features of life-threatening and life-ending Covid-19 disease is the now-infamous “cytokine storm,” a surge of inflammation-summoning molecules that, in an attempt to eradicate the infection, ends up mutilating the tissues of the lungs, heart, kidneys, or other organs. Like burning down a house to rid it of rats, the immune system’s remedy can be worse than the threat.

So far, SARS-CoV-2 has sickened more than 30 million people worldwide. Its death toll has exceeded 1 million. But a large percentage of those infected — by most estimates, somewhere around 40% to 45% of carriers — seem to endure the virus without symptoms or lingering effects.

Unlike “disease resistance,” which refers to all of the body’s methods of killing…