Substance P as a Biomarker to Evaluate the Reduction of Multiple Immunization Pain

Inclusion Criteria: * All healthy children who were attending immunization clinic to have their 10-24 month immunization were invited to this study Exclusion Criteria: * Exclusion criteria included children: whose parents choose to breastfeed during immunization, who have received an analgesia in the previous 24 hours including Paracetamol (so as not to affect the response to painful stimuli during immunization), who cannot receive their immunization due to the presence of immunization risk factors as determined by the immunization nurse, who are not able to receive a sugar solution, and whose parents refuse to participate.