Maternal pertussis vaccination behavior: Psychosocial, attitudinal and organizational factors

Background: In December 2019, the maternal pertussis vaccination (MPV) became part of the Dutch National Immunization Program. This study aims to study MPV behavior and associated psychosocial, attitudinal and organizational factors of pertussis vaccination behavior during pregnancy in the Netherlands. Methods: We conducted a cross-sectional survey among pregnant women and recent mothers, up to six months post-partum. The primary outcome measure of this study was MPV behavior. Associations between psychosocial, attitudinal and organizational factors and MPV behavior were assessed using univariate and multivariate binary logistic regression analysis. Results: In total 1348 participants filled out the questionnaire, including 1282 (95.1%) MPV acceptors and 66 (4.9%) MPV refusers. The most important factors associated with MPV behavior were: attitude (aOR: 10.19; 95% CI: 4.30-24.16), outcome expectations (aOR: 8.94; 95%CI: 3.60-22.21), omission bias (aOR: 0.11; 95%CI: 0.02-0.59) and physical accessibility (aOR: 7.44; 95%CI: 3.37-16.46). Conclusion: Pregnant women make their decision about the MPV primarily based on attitudinal and psychosocial factors, such as outcome expectations and attitude. A combination and variation of different messages, about the advantages (effectiveness) and disadvantages (side effects) of maternal vaccination, can be used in reaching pregnant women with a positive and negative attitude about the MPV. In addition, strategies to increase MPV uptake should not only focus on providing information, but also decrease experienced practical barriers, such as poor physical accessibility, in people that are intended to receive the MPV but are not getting vaccinated.