comparison of vaccination‑related pain in infants who receive vapocoolant spray and breastfeeding during injection

background: vaccination is one of the most common painful procedures in infants. despite the irreparable consequences and complications of acute pain in infants, and existence of pharmacological and non‑pharmacological methods for pain control, pain control in infants has received less attention. therefore, this research aimed to compare the vaccination‑related pain in infants younger than 6 months who receive vapocoolant spray and breastfeeding during injection, in order to suggest a strategy to provide emotional, mental, and physical health for infants.   materials and methods: this is a randomized clinical trial study on 144 infants less than 6 months of age, referred to ibn sina health care center in 2009, who were selected by convenience sampling. forty‑eight infants were allocated through systematic random sampling to each study group (i.e., breastfeeding, vapocoolant spray, and control group). inclusion criteria were: fully conscious infants, lack of any disease (sensory, motor abnormalities, cold, etc.), taking no medication, exclusive breastfeeding, vaccination for hepatitis b and dtp, regular visits to health care center, infants with iranian nationality, and quiet infants who did not cry. the infant was excluded if he/she was crying and it was impossible to make him/her quiet before injection. data were gathered by a questionnaire (six questions) and checklist [neonatal infant pain scale (nips)]. data were analyzed by descriptive and inferential statistical methods through spss.   results: the findings suggest that breastfeeding during vaccination has a more analgesic effect on vaccination pain, compared to application of vapocoolant spray before vaccination. in 64.6% of the infants, breastfeeding during vaccination caused analgesia, while 25% of the infants who received vapocoolant spray experienced analgesic effect. there was a significant difference in pain between the infants who received vapocoolant spray and those on breastfeeding during injection ( p < 0.001).   conclusion: it seems that breastfeeding during vaccination in infants under 6 months of age is an effective, natural, safe, accessible, and inexpensive method without side effects to reduce vaccination‑related pain.