This concept could be used to make you react to anything against which an antibody can be made. Some people have vaccine induced glycerin intolerances for example. In addition to fetal tissue and FBS, vaccines also often contain pig skin gelatin and egg proteins, meaning you can become allergic to chicken, pork, beef, and your own body from these injections (not specifically the mRNA ones, all vaccines). Never take a single one and never give them to your children.