It is common for a small lump to remain at the injection site for a few weeks after vaccination. .. it is ususllyy . harmless, especially if there is no redness, or swelling or warmth.... Some pain on pressing can happen, but it should gradually reduce. You can do gentle massage with warm compress if baby allows. If the lump increases in size, becomes red, hot, or baby develops fever, then please show your pediatrician. Otherwise no treatment is needed

Hey. It isn’t uncommon for a baby to develop a lump post vaccination at the injection site. It might another few days for it to resolve. You can do cold compresses at the local site and wait for self resolution over the next few days. No treatment required.

No need any treatment if there is no local redness and pus formation.