The effect of stress on the antibody response after vaccination in children aged 0-18 years: A systematic review

Stress has been associated with less effective vaccine responses in adults. This review aims to investigate the evidence for a similar association in children. A systematic review search was conducted in January 2021 in three databases: Medline, Embase and PsycInfo. An updated search of the Medline database was systematically conducted until the most recent update on September 25th, 2023, to ensure the inclusion of the most current research available. Keywords related to stress, vaccines and children were used, and a total of 7263 (+1528) studies were screened by two independent investigators. Six studies met the inclusion criteria for data extraction and analysis. For quality assessment of the studies, the risk of bias in non-randomized studies-of interventions (ROBINS-I) tool was applied. Most of the studies suggest a negative role of stress on vaccine responses. However, the scarcity of studies, lack of confirmatory studies, risk of bias and heterogeneity according to age, type of vaccine, measures of stress and vaccine responses prevent a clear conclusion. Future studies should emphasize the use of as strict study designs as possible, including well-defined stress metrics and thorough examination of both pre- and post-vaccination responses. Systematic review registration: Prospero CRD42021230490.