IntroductionDespite historical exclusion, there has been recent recognition of the need to address the health of pregnant women in research on vaccines against emerging pathogens. However, pregnant women’s views and decision-making processes about vaccine research participation during infectious disease outbreaks remain underexplored. This study aims to examine women’s decision-making processes around vaccine research participation during infectious disease outbreaks. MethodsWe conducted qualitative semi-structured in-depth interviews with pregnant and recently pregnant women (n = 13), eliciting their views on four hypothetical Zika Virus vaccine research scenarios and probing their decision-making processes around participation. After recorded interviews were transcribed, thematic analysis was conducted based on a priori and emergent themes. ResultsMost women interviewed were accepting of vaccine research scenarios. Three broad themes—evidence, risk, and trust—characterized women’s decision-making processes. Women varied in how different types and levels of evidence impacted their considerations, which risks were most salient to their decision-making processes, and from whom they trusted recommendations about vaccine research participation. Exemplary quotes from each theme are presented, and lessons for vaccine development during the current COVID-19 pandemic and future outbreaks are discussed. ConclusionSome pregnant women are accepting of participation in vaccine research during infectious disease outbreaks. Incorporating their priorities into trial design may facilitate their participation and generation of evidence for this important population.