Vaccines: What’s Inside Them and Are They Safe?

While there are many types of vaccines, each falls into one of a few broad categories. But can vaccines make you or your child sick? Because they don’t contain live pathogens, it’s impossible for mRNA vaccines, protein-based vaccines, and those with a killed version of the bacterium or virus to cause you to fall ill. In live, attenuated vaccines, the bug is living but rendered useless.