Immunity

Immunity is an introductory guide to how your immune system works, why it’s a double-edged sword, and which laws govern its existence.

Smallpox killed hundreds of millions of people over several thousand years. In the 18th century, it was discovered that milkmaids, who often acquired cowpox, a less dangerous variant of the disease, tended to be immune to smallpox later on. Since the two diseases were closely related, it was hypothesized that being exposed to cowpox could help build immunity and protect people from smallpox.

That’s how the concept of vaccination was born. What happens when you get vaccinated is that you’re simply being injected with a small dose of the virus (or a related one), thus triggering an immune response, getting your body to produce cells killing the virus.

Your immune system is smart. It remembers. So the next time you’re exposed to the same virus, it’ll be fought off instantly. That’s the power of your immune system, and thanks to boosting it with vaccines, smallpox is a thing of the past – it’s one of two infectious diseases that’s been eradicated, worldwide.

However, a malfunctioning immune system can turn against you, causing so-called autoimmune diseases, where your body fights against itself. Some of these are life-threatening, since they cause the body to destroy some of the most crucial cells, such as diabetes type 1, lupus or multiple sclerosis.

But how does your body react when a few pathogens – cells that cause diseases – sneak in?

There are three potential responses, and they depend on the stage and severity of the illness.

First, your body has physical barriers to keep out pathogens, such as a slimy layer of mucus on your airways, which catch them before they’re swallowed and destroyed by your stomach acid (or blown out with a good sneeze).

Second, there’s your innate immunity, which also catches pathogens early on, usually a few hours after they enter the body. In this case some cells of your body detect the intruders, call immune system cells to help, and fight them off.

Third, there’s adaptive immunity, in which highly specialized cells are produced, specifically to deal with the pathogens of that particular disease (think SWAT team). The cool part of triggering this response is that a few of these cells stick around after the disease has been beaten, thus strengthening your immune system, and working like a vaccine.

Cancer is one of the worst diseases of modern times, and even though it has somewhat autoimmune effects, the immune system just might be able to fight it off! Researchers found when looking at people before hepatitis-B vaccination, cancer was common and after it was standard practice, showed an 80%+…