‘Immunity debt’: Why experts say this new term promotes COVID-19 ‘misinformation’

The term "immunity debt" is circulating as an explanation of a surge in illness in Canada, but infectious diseases experts say it's “dangerous” and promotes COVID “misinformation.”

The term “immunity debt” is circulating widely online as an explanation for a significant surge in respiratory illness in Canada, but infectious diseases experts say the term and the narratives around it are “dangerous” and can promote COVID-19 “misinformation.”

Two variations of how “immunity debt” is being interpreted have emerged in recent weeks, as emergency departments and children’s hospitals across the country have been swamped with more patients sick with respiratory viruses than they can handle.

The first hypothesis suggests people’s immune systems are weaker now, due to a lack of exposure to viruses while observing COVID-19 public health measures over the last two-and-a-half years.

But this notion that governments and public health officials have been “coddling” the public’s immune systems by wearing masks and staying home and that this has eroded people’s immunity to other viruses like influenza or respiratory syncytial virus (RSV) is simply not true, says Colin Furness, an infection control epidemiologist and assistant professor in the faculty of information at the University of Toronto.

“That is, in my estimation, and any immunologist will tell you this, nonsense,” he said.

“It imagines that the immune system is like a muscle where, if you’re not using it, then you lose it, it atrophies.”

In fact, Furness likens the immune system to a collection of photographs. When people take photos and put them away in an album, the photos don’t fade over time just because they aren’t being looked at regularly.

With age, the immune system does start to become less effective at preventing illness, in the same way an elderly person might find it harder to see their photos as their eyesight weakens.