Immunity - Simplified

I once heard a very good analogy for how our immune system works during a podcast in the COVID era.
The professor compared it to a country’s security forces.
• At the lowest level, you have the Police, patrolling daily life.
• As the threat rises, Armed Police arrive.
• If things escalate, the Army is deployed.
• And finally, when the stakes are highest, Special Forces step in.

It’s a simple but powerful way to think about how our immune system defends us.

We often hear about the microbiome — the friendly bacteria that live in and on us, helping digestion and even mood regulation.
But less often do we talk about the unhelpful bacteria that also reside with us — like pneumococcal bacteria— the potential troublemakers our body’s “security forces” have to constantly keep in check.

And our immune system’s duties don’t stop at fighting infections. It’s also constantly surveilling and sweeping up misbehaving cells, the kind that could eventually become cancer.

As we age or get worn down, those defences can weaken. Our “police” become less effective; response times slow. Which is why pneumonia is often the illness that carries many old people away.

Personally, I’ve noticed that if I get chilled to the bone, within 24 hours I’ll develop what I call ‘mild man flu’ — my equivalent of the local police temporarily losing control of the streets. Thankfully, the “armed cops” soon arrive to restore order.

PS If your Special Forces can’t deal with the invader eg Ebola virus you’re in deep doody…