Hi, swelling and lump are common side effect of pentavelant vaccine. Please follow some rules while vaccinating. 1. Hold the injection site wit cotton with moderate pressure for 2 min, release after 2 minand check for bleeding if no bleeding then remove cotton else hold for another 2 min till blood does not oiz from injection site. 2. When you r back home apply ice pack or 3 ice cubes in a cloth at injection site for 1/2-1 Min 3 times a day for 2 days and 3. Give paracetamol as pain killer Disclaimer "This provisional advice provided by me stands subject to the patient undergoing a physical examination and is based entirely on inputs provided by patient/attendants. The patient is advised for physical examination at earliest"

Swelling and redness is most common adverse effect and shortlived effect ,you don't have to worry ,it subsides gradually for most of children.