The effect of breastfeeding on reducing pain induced by pentavalent vaccine in infants: a randomized clinical trial.

Objective: To analyze the effect of breastfeeding on reducing Pentavalent vaccination pain in infants and to identify the necessary breastfeeding interval for antinociceptive action.

Method: Open parallel randomized clinical trial. Ninety mother-infant dyads participated, distributed into intervention group 1 (n = 30), which breastfed five minutes before vaccination; intervention group 2 (n = 30), which breastfed five minutes before and during vaccination; and control group (n = 30), which did not breastfeed. The outcome variable was the pain level measured by the FLACC Scale. Data analysis was conducted using descriptive and inferential statistics, applying Fisher's Exact, Kolmogorov-Smirnov, Kruskal-Wallis and Dunn's multiple comparison tests, with 0.05 significance level.

Results: Pain induced by the Pentavalent vaccine was reduced in intervention groups 1 and 2 (mean pain of 6.06 versus 3.83, respectively) compared to the control group (mean of pain of 7.43), which was significant for intervention group 2 (p < 0.001), indicating that, to achieve lower levels of pain, breastfeeding should be carried out before and during vaccination.

Conclusion: Longer breastfeeding, conducted five minutes before and during vaccination, reduces the pain induced by the Pentavalent vaccine. No vaccination risks were identified to outweigh the benefits. These results endorse that health professionals should encourage breastfeeding at least five minutes before and during vaccine injection for an antinociception effect. Brazilian Clinical Trials Registry: RBR-9vh37wr.