Final DTap shot - reaction

[lucy4]

I am reading a lot that a final shot of DTaP is when kids have a reaction... if they have it at all to DTaP. Why last dose? Do they put something different in it, or is it exact same ingredients as in first and second shots?

[TanyaS]

The ingredients are the same. The chance of a reaction can happen with any dose. I'm not sure if anyone knows why or if it is more likely to happen. Overload on the body? Too much aluminum? There's not exactly a lot of scientific studies into why vaccine reactions occur.

[denimtiger]

All doses are the exact same ingredients, in the exact same amount and potentcy... the dose for a 10 lb. 2-month-old is the same as for a 50 lb. 5-year-old.

It is most common for children to react to the fourth and fifth doses because the vaccine is a toxoid vaccine. If children (or anyone, for that matter) have developed enough immunity to the tetanus toxoid, the body's immune system will react to the toxoid in the vaccine. A "common" reaction is having the entire arm or leg where the vaccine was given swell up. This is why adults are not supposed to receive doses of tetanus vaccine too close together -- the immunity they already have to tetanus will react.

[lucy4]

Originally Posted by denimtiger

All doses are the exact same ingredients, in the exact same amount and potentcy... the dose for a 10 lb. 2-month-old is the same as for a 50 lb. 5-year-old.

It is most common for children to react to the fourth and fifth doses because the vaccine is a toxoid vaccine. If children (or anyone, for that matter) have developed enough immunity to the tetanus toxoid, the body's immune system will react to the toxoid in the vaccine. A "common" reaction is having the entire arm or leg where the vaccine was given swell up. This is why adults are not supposed to receive doses of tetanus vaccine too close together -- the immunity they already have to tetanus will react.

So it's like your body is saying - "I didn't need this dose, I am immune"?

[Emmeline II]

Originally Posted by lucy4

So it's like your body is saying - "I didn't need this dose, I am immune"?

I don't think so.

Allergies develop after exposure; it may just have taken multiple exposures before a discernible or significant reaction occurs. Posters that report a significant 4th dose reaction, often look back and see other signs that they or their doctor's dismissed as "normal."

Also, individuals process things at different rates; perhaps some have a "build-up" that finally results in a significant reaction.