Related Experiment Video
Updated: Apr 12, 2026

Comprehensive Evaluation of the Effectiveness and Safety of Placenta-Targeted Drug Delivery Using Three Complementary Methods
Published on: September 10, 2018
Pharmacovigilance analysis of vaccination errors during pregnancy using VAERS data
Kenneth L McCall1, Jae Hee Park2, Taylor M Clark1
1Binghamton University School of Pharmacy and Pharmaceutical Sciences, Johnson City, NY 13790, USA.
Background/Objective:
Vaccination during pregnancy protects both pregnant individuals and infants, yet real-world data on administration errors in this population are limited. We aimed to identify and characterize safety signals for vaccination errors during pregnancy using the Vaccine Adverse Event Reporting System (VAERS).
Methods:
We conducted a retrospective analysis of VAERS reports from January 1, 2023, to May 30, 2025, involving vaccinations administered during pregnancy. Disproportionality was assessed using PRR (>2), ROR (signal if lower 95% CI > 1), EB05 (>2), and IC025 (>0) for error types with ≥5 reports.
Results:
Of 171,958 unique VAERS reports, 1413 involved vaccinations during pregnancy. Several vaccine-error pairs showed moderate to strong signals: RSV-wrong product (PRR 6.8; ROR 10.3, 95% CI 7.4-14.6; EB05 1.8; IC025 0.8), TDAP-extra dose (PRR 9.7; ROR 11.6, 95% CI 6.7-20.3; EB05 3.0; IC025 1.6), TDAP-storage error (PRR 15.4; ROR 17.7, 95% CI 8.5-36.6; EB05 3.2; IC025 1.7), and influenza-expired product (PRR 8.3; ROR 8.8, 95% CI 3.4-22.4, EB05 1.8; IC025 0.9). Live vaccine administrations (MMR n = 35, varicella n = 42) were reported, with 47.6% unaware of pregnancy at vaccination. No birth defects or deaths were reported among vaccine-error pairs.
Conclusions:
Vaccine administration during pregnancy showed disproportionate reporting of specific errors, especially RSV-wrong product, multiple TDAP-related errors (extra dose, storage) and live vaccine administration, with no severe outcomes reported. Findings suggest practical targets for error prevention to reduce wrong-product and scheduling errors while maintaining access to indicated maternal immunizations.
Related Concept Videos
Pharmacovigilance
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
Vaccinations
Teratogenicity
Analysis of Population Pharmacokinetic Data
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...
Bias in Epidemiological Studies
