Objective: To determine, whether or not intramuscular injection of diphtheria, pertussis and tetanus (DwPT) vaccine should be given first and subcutaneous injection of measles, mumps and rubella (MMR) thereafter or vice versa and can this cause less pain of DwPT vaccine injection.
Methods: In a randomized parallel group clinical trial, seventy 18-mo-old healthy children who were referred for routine vaccination to Akbari Health Care Center, Yazd, Iran from September 2014 through March 2015 were randomly allocated to two groups to receive DwPT and then MMR vaccines or MMR first, and then DwPT. Primary outcomes included pain score during DwPT injection, pain score during MMR injection, overall pain score of vaccination and obtaining a pain score of less than three during DwPT injection. Pain scores were assessed based on Modified Behavioral Pain Scale. Secondary outcome was crying duration during DwPT injection.
Results: Thirty seven girls and 33 boys were evaluated in two groups. Pain scores of DwPT and MMR injections, the frequency of pain score obtained to be less than three during DwPT injection and the crying duration were not different in both groups. But, overall pain score of vaccination was lower when subcutaneous injection of MMR vaccine was given before intramuscular injection of DwPT vaccine. (14.23 ± 1.35 vs. 15.61 ± 2.65; P = 0.04).
Conclusions: Overall pain score of vaccination in multiple vaccine injection at the same visit might be reduced if subcutaneous vaccine is injected before intramuscular one.
Keywords: Child; DwPT; MMR; Order; Pain; Vaccination.