Immune: A Journey Into the Mysterious System That Keeps You Alive

by Philipp Dettmer

upgrade their immune system and protect them against the target of the vaccine for the remainder of their lives. Using living pathogens is not always an option though. Just like you can’t domesticate great white sharks, some pathogens refuse to be tamed and become properly weak. In some cases the risk of them causing the disease we want to protect against is just too high. So another method is to straight up kill the pathogen before injecting it, which is called an inactivated vaccine. You get a high number of the pathogenic bacteria or viruses together and then you destroy them with chemicals, heat, or even radiation. The goal is to destroy their genetic code so they are empty and dead husks, unable to reproduce and go through their life cycles. But this also creates a problem. Can you imagine what? They are too harmless now! Your immune system will not be properly provoked by a bunch of carcasses of pathogens that just float around and are pretty dead. So the dead remains of the pathogens have to be mixed with chemicals that highly activate the immune system. You can imagine these chemicals like insults that provoke a disproportionate response, like running around wearing the jersey of the opposing team and insulting the home team in a city that just has lost a major sporting event. Chances are at some point someone will punch you in the face. If dead bacteria are mixed with substances that really put the immune system on edge, your immune cells will not be able to make ...