evidence: Vaccines don't cause food allergies. Here's what parents need to know about vaccines and food allergies. [...] The fact that vaccines don't cause food allergies has been proven by several well-controlled studies. [...] Even though vaccines don't cause food allergies, some people with existing food allergies still need to be cautious about certain vaccines. If a vaccine contains a food that they are already allergic to, it may cause them to develop an allergic reaction. They might even develop anaphylaxis, a severe allergic reaction that requires immediate emergency attention.