Deferring Risk: Limitations to the Evidence in Product Labels for Vaccine Use in Pregnancy.

Background: The gaps in clinical trial evidence about vaccination in pregnancy have serious implications for health care worker and public misunderstandings. Contradictions between National Immunization Technical Advisory Group (NITAG) recommendations and regulatory product labeling information contribute to misinformation about vaccine safety and effectiveness. Methods: A mixed methods approach that included a stakeholder consensus decision-making workshop and a national survey of Canadian health care providers (HCPs). Results: We identified knowledge gaps and serious limitations concerning the information in vaccine product labels. Stakeholders were troubled that some HCPs rely on regulatory product labels to inform their decisions without knowing their limitations in content. Our survey showed that HCPs were uncertain about the purpose of product labels and the evidence contained in them. Over a third of respondents incorrectly thought that product labels and NITAG recommendations are based on the same evidence and that the information they contain is regularly updated. Conclusions: Applying social risk theories, we show how such gaps in information defer responsibility for decisions about disease risk and vaccine safety from regulatory agencies and vaccine manufacturers onto HCPs and their clients. This may be especially relevant for COVID-19 and other emerging vaccines that are initially authorized for conditional or emergency use, and especially in understudied populations such as pregnant people. More frequent updating and alignment of robust, unbiased, and independently reviewed clinical trial and postmarket safety and effectiveness evidence with NITAG recommendations would allay HCP and public misunderstandings.