![[This image shows three pathogens, including measles, chicken pox, and the flu respectively, with their existing antibodies that have built up due to exposure of disease within our bodies. The last antigen shown is a new pathogen with no antibody near it because it is a new exposure.]](https://blogs.iu.edu/sciu/files/2021/01/vaccines-antibody-illustration-01-29-oct7f4a97bd839b4b6996c82c1832a52682.jpg)
Vaccines remain a hot topic in this country, especially due to the COVID-19 pandemic. To understand the importance of why we should be vaccinated, we first must understand how the immune system responds to an infection. When a disease-causing microorganism, called a pathogen, is introduced into our bodies, our immune system is signaled to initiate an attack on this intruder. Specifically, our immune system will try to stop the pathogen from multiplying, which will prevent the pathogen from spreading and decrease the infection.