Why do some injections hurt and others don't?

Question

We are having an injections course at school. The injections we are getting are Chicken Pox, Hepatitis B and the new Cervical Cancer vaccine. You can hardly feel the Chicken Pox injection, the Hepatitis B one stings and the Cervical Cancer vaccine is very painful. Why is this so?

Answer 1

The aluminum in the Hepatitis B vaccine and the HPV vaccine is what makes them hurt.  The chickenpox vaccine does not contain aluminum.

Here is the ingredients list for the HPV vaccine

http://www.merck.com/product/usa/pi_circ...

For the Hep B vaccine:

http://www.merck.com/product/usa/pi_circ...

For the chickenpox vaccine:

http://www.merck.com/product/usa/pi_circ...

Answer 2

It really depends on the type of the medicine. Some medicine is more thick than others, which means that it hurts more. And of course some medicine stings more than others.

Answer 3

its not really the needle that stings its the medicine thats injected into that gives the stinging sensation

Answer 4

All of the above answers are very good, plus you have to realize it's the person giving the injection that has a certain technique, they can poke in the wrong spot, their angle, etc...

Answer 5

It depends on the medication. If the PH level of the injection is higher than your bodies PH level then it tends to sting a lot more, also if the vaccine has come strait from a fridge it will sting more too.