Is there a difference between a 'vaccine reaction' and an 'allergy to a vaccine'?

[Sarah111213]

I was just wondering - one of my friends' children had a 'vaccine reaction' which involved vomitting and collapsing, but airway swelling, or any other symptoms you'd associate with a vaccine.

Is this a 'reaction' but not an 'allergy'?

An allergic reaction is a term given to what are also known as hypersensitivity reactions, of which they are several types.

Type 1 is the group where anaphylaxis (the potentially lethal allergic reaction) and hayfever are located.

So a Type 1 Hypersensitivty reaction to a vaccine (or one of it's components) could give you a rash/swelling at injection site or trouble breathing due to a swollen windpipe depending on how local the reaction remains.
These are, thankfully, very rare.

An adverse response to a vaccine is where you get symptoms after an injection but which are not related to this type of immune response.
Fever and sore throat are not uncommon.

These are not allergic in nature.

Does that make sense?

That makes perfect sense, DBennett - thankyou very much!