Congratulations! You are an evolutionary miracle! Your body is specialized to fend off foes using a complicated system you may have heard about before: your immune system. Yes, the system that fends off the flu, gives you allergies, and makes your knee swell up when you fall down the stairs in Van Meter trying to get back to your dorm after your night class. Your immune system can be broken into two parts: your innate and adaptive immune responses. Your innate immune response is the first line of defense, causing responses like sneezing, itching, inflammation—all that fun stuff. Innate immunity works with brute force, attacking in the same manner and without discrimination against anything foreign.
Your adaptive immune response picks up when brute force no longer does the trick. This response relies on specificity, diversity, and memory, as two immune cells called T cells and B cells take over. These two cell types are capable of remembering viruses and bacteria they have seen in the past. After your body wins its battle with a pathogen, special T cells sit around like your best friend after your break-up: picturing your ex (the pathogen) in their head, waiting until the moment they show their face again so they can beat the crap out of them. When and if that ex/pathogen reappears, T cells also alert B cells, so they can work together to eliminate that threat.
Having this ability to remember is what allows for the success of vaccines. Getting vaccinated is like handing over the picture of your ex (the unique exterior of the pathogen) to your T cells without having to go through any of the emotional trauma of the relationship (the interior of the pathogen that makes you sick). Pretty great, right? If you get too deep into the science, you will soon realize that immunology is immensely complicated and confusing, but the point is: vaccines work because your immune system remembers. Now that you understand why you would want to inject a little bit of dead pathogen into your body: what the heck is in that flu shot that isn’t dead pathogen?
The Center for Disease Control lists the main ingredients in vaccines as preservatives, adjuvants, stabilizers, residual cell culture materials, and residual inactivating ingredients. If you can get past the absurd vocabulary and really take a look at the five parts of the vaccine, you will find surprisingly familiar ingredients. Preservatives are necessary in preventing contamination of the vaccine, but in day-to-day life you often ingest the same preservatives by eating certain foods, such as fish. Adjuvants function in the vaccine to boost your body’s response, but are more commonly found in drinking water, infant formula, antacids, and aspirin. Stabilizers are necessary to keep the vaccine effective post-manufacturing but are also quite delicious! Common stabilizers are sugar and gelatin, or, ingredients you would ingest by eating a cup of Jell-O. Residual cell culture materials and residual inactivating ingredients are miniscule portions of the entire vaccine concoction left over from manufacturing, the former being produced as the virus or bacteria is grown in the lab, and the latter used to kill the virus or inactivate toxins. Formaldehyde is typically used as an inactivating ingredient, which sounds scary, but formaldehyde actually exists naturally in your body at a far higher level than the level present in the vaccine!
Really, it comes down to this: your beautiful and sophisticated immune system uses vaccines to remember what pathogens look like, so later on when you’re infected with the real deal, your body knows it is time to destroy and can quickly produce pathogen-attacking cells to do so. And all those nasty ingredients they are injecting into your arm? They aren’t so nasty after all! They can be found in fish, eggs, water, Jell-O, baby formula, and even just floating around your body as is. Vaccines are nothing to fear, but rather are an amazing feat of modern medicine that helps us avoid not-so-fun things, like, you know, The Plague.
By: Isabella Davis