This year’s flu shot will be missing a strain of influenza it’s protected against for more than a decade.

That’s because there have been no confirmed flu cases caused by the Influenza B/Yamagata lineage since spring 2020. And the Food and Drug Administration decided this year that the strain now poses little to no threat to human health.

Scientists have concluded that widespread physical distancing and masking practiced during the early days of COVID-19 appear to have pushed B/Yamagata into oblivion.

  • @WoahWoah
    2•1 month ago

    For those saying we should do it again or more often, that isn’t always a good idea. Doing it when you’re sick or when there is a new and novel outbreak makes sense. But the idea that prolonged masking and distancing could eliminate illness overlooks how human immunity and viral evolution actually work. While it’s true that measures like these reduced flu cases and even eliminated a particular strain during the pandemic, immunity is a dynamic system. The immune system is constantly exposed to various viruses and bacteria, which helps it “train” to recognize and fight off future threats. If we stop exposing ourselves to these relatively mild infections, our immune defenses could become unprepared for more serious illnesses when they inevitably re-emerge or mutate.

    Viruses, especially, evolve rapidly. While masking might reduce transmission in the short term, viruses like influenza and coronaviruses mutate through processes like antigenic drift, which can make them unrecognizable to our immune systems even after we’ve built up some resistance. We saw this recently with the rise in RSV (respiratory syncytial virus) infections, particularly in children. After pandemic restrictions reduced exposure, many children lacked the usual low-level exposure that would have primed their immune systems. As a result, when RSV returned, it hit harder. So while distancing and masking can temporarily protect us, they don’t provide a long-term solution for maintaining strong, adaptable immune systems.

    Just being out there in the soup of viruses and bacteria, keeping your immune system resilient, and taking advantage of immunizations when possible is really the best, only, and most time-tested practice.