In “Why Vaccines Work” by It’s Okay To Be Smart, host Joe Hanson explains the history of vaccines, the science behind vaccines, and how they work.
“Our immune system is on constant alert against germy baddies, with millions of white blood cells each on the lookout for specific infections. When an immune cell meets its target, it replicates itself and this clone army sends a barrage of protein weapons called antibodies to label the trash for cleanup. After the infection is gone, so-called memory cells stick around, ready to mount a fast attack in case the germ shows up again. This is how we develop immunity, and it works pretty well… since we’re all still alive. But even with all that, some super-bad germs can take us out before our immune sentries have had time to call up that clone army, this is especially true for young children, their immune systems are fresh out of basic training. Thankfully we have vaccines, which are made of tiny pieces or weakened versions of viruses or bacteria. They let our immune system see what the bad guys look like, and recruit those all-important memory cells before we ever have to actually see the real enemy.”