Navigating Immunization in Pregnancy: Evaluating Safety and Strengthening Policy

Vaccine injection procedure on pregnant women.

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Administering vaccines during pregnancy is recognized for its potential benefits in protecting both the pregnant individual and the developing fetus. However, understanding the spectrum of adverse events following immunization (AEFIs) in pregnancy remains a challenge.

The study emphasizes the intricate nature of AEFIs during pregnancy, encompassing outcomes conventionally evaluated in vaccine recipients, as well as pregnancy-related complications such as loss, preterm delivery, and fetal growth anomalies. Despite the importance of understanding these risks, pre-licensure data often lack enough pregnant individuals to gauge safety signals effectively.

Moreover, public health programs inadequately describe post-licensure evaluation systems for immunization during pregnancy. In response to these challenges, the study reviewed all Pregnancy Exposure Registries mandated by the US Food and Drug Administration (FDA) and documented in manufacturer package inserts for vaccine products in the US.

“Vaccination-in-pregnancy evaluation systems led by federal or academic organizations attempt to fill some, but not all, gaps in safety assessments,” according to the investigators. “For example, the US military leads evaluations of vaccines used as bioweapon countermeasures, and CDC leads the primary evaluation system for COVID-19 vaccines.”

The review outlines these registries' procedures and data elements, highlighting both open and closed registries. Additionally, it examines specialized vaccine-in-pregnancy evaluation systems led by federal and academic organizations, offering comparisons to manufacturer-led efforts.

However, despite efforts to establish registries, the study reveals inconsistencies in their establishment and operation. Among the 75 FDA-approved vaccine products, only 21 currently have manufacturer-led registries, and the alignment of these registries with potential vaccination risks during pregnancy remains unclear.

Efforts led by federal or academic organizations aim to address some of the gaps in safety assessments. Challenges persist in evaluating the safety of immunizations during pregnancy, emphasizing the critical need for strict policy and enhanced evaluation systems to benefit public health transparency and vaccine confidence.

Reference

Ryan M, Angelo S, Delapena K, et al. (2024) Immunizations in Pregnancy: Challenges and Opportunities for Vaccine Safety Evaluations. Oral Abstract #19 presented at NFID 2024 Annual Conference on Vaccine Research. May 8-10. Online.