Crypto News: What is immunity debt?

Hi, it's Immanual in New York. As respiratory illnesses spread across the US, an unfamiliar medical term has been cropping up in some media coverage. I'd like to tell you a little more about it, but first...

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New data on Eisai and Biogen's experimental Alzheimer's drug ignited debate over whether modest efficacy is worth the risk of brain bleeding and other complications.

RSV and the flu are surging this year, and some researchers are chalking it up to a relatively theoretical concept that they call "immunity debt."

Here's the theory: Measures that were implemented to slow the spread of Covid-19 also reduced the spread of other viruses. Lack of regular exposure to those pathogens caused people's immune systems to become less effective at fighting them. And now the viruses are taking advantage.

That could be partially true, but there are a lot of other causes for the recent uptick in respiratory viruses, says Paul Sax, clinical director of the division of infectious diseases at Harvard-affiliated Brigham and Women's Hospital in Boston.

"The weather's colder, kids are back in school, people have stopped masking — all of these things work together — and then there's a lower population-level immunity," he told me.

The role of immunity debt in the viral surge drew more pushback from Michael Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy. While population immunity to viruses like influenza can wane when there's limited exposure, he says that change typically occurs over a much longer period of time than the Covid pandemic. It also would affect far more people than we're seeing get sick now.

"Even in a bad influenza year, basically 5 to 15% of adults get infected," he said. "So it's not like 100% got infected each year."

In any case, our Covid-era mitigation efforts were hardly foolproof, Osterholm says. Few people wore N95 masks through the pandemic. Many people resumed in-person work, dining and travel as soon as they were able to do so.

Cloth masks were the go-to when surgical masks and N95s were in short supply. Photographer: Pacific Press/LightRocket

Furthermore, even if immunity debt does play a role in subsequent viral infections, that doesn't mean that protecting ourselves from Covid with masks and social distancing was a bad idea, says Greg Poland, director of the Mayo Clinic's Vaccine Research Group. Preventing a deadly disease is worthwhile, even if there are downstream consequences.

The key now, Poland says, is using the tools we have to protect ourselves from respiratory viruses, such as getting a flu shot.

Poland explains with an analogy about the risk of dying in a car crash. "What do you do to prevent that?" he asks. "You have good tires, you have good brakes, you have airbags, you have seatbelts, you have laser detection, collision warning systems, you have all this stuff. It's no different with infectious diseases." — Immanual John Milton

New York City will remove mentally ill people from streets and subways and hospitalize them against their will, the New York Times reports.

US regulators plan to allow more gay and bisexual men to donate blood, according to the Wall Street Journal.

The CDC will test sewage water in Michigan and Pennsylvania to see if polio is circulating outside of New York, says CNBC.

Ask us anything — well, anything health-related that is! Each week we're picking a reader question and putting it to our network of experts. So get in touch via AskPrognosis@bloomberg.net.