Applicability of the GAIA Maternal and Neonatal Outcome Case Definitions for the Evaluation of Adverse Events Following Vaccination in Pregnancy in High-income Countries.

BACKGROUND

The Brighton Collaboration Global Alignment of Immunization Safety in Pregnancy (GAIA) project developed case definitions for the assessment of adverse events in mothers and infants following maternal immunization. This study evaluated the applicability of these definitions to data collected in routine clinical care and research trial records across 7 sites in high-resource settings.

METHODS

Data collection forms were designed and used to retrospectively abstract the key elements of the GAIA definitions from records for 5 neonatal and 5 maternal outcomes, as well as gestational age. Level of diagnostic certainty was assessed by the data abstractor and an independent clinician, and then verified by Automated Brighton Case logic. The ability to assign a level of diagnostic certainty for each outcome and the positive predictive value (PPV) for their respective ICD-10 codes were evaluated.

RESULTS

Data from 1248 case records were abstracted: 624 neonatal and 622 maternal. Neonatal outcomes were most likely to be assessable and assigned by the level of diagnostic certainty. PPV for preterm birth, low birth weight, small for gestational age and respiratory distress were all above 75%. Maternal outcomes for preeclampsia and fetal growth restriction showed PPV over 80%. However, microcephaly (neonatal outcome) and dysfunctional labor (maternal outcome) were often nonassessable, with low PPVs.

CONCLUSIONS

The applicability of GAIA case definitions to retrospectively ascertain and classify maternal and neonatal outcomes was variable among sites in high-resource settings. The implementation of the case definitions is largely dependent on the type and quality of documentation in clinical and research records in both high- and low-resource settings. While designed for use in the prospective evaluation of maternal vaccine safety, the GAIA case definitions would likely need to be specifically adapted for observational studies using alternative sources of data, linking various data sources and allowing flexibility in the ascertainment of the elements and levels of certainty of the case definition.

Informations de copyright

Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.

Déclaration de conflit d'intérêts

A.K. has worked as a consultant for GlaxoSmithKline and Pfizer on maternal immunization projects not related to this study. F.M.M. is a member of the DSMB member for various vaccines including for maternal immunization for Pfizer, Moderna and the US National Institutes of Health. She has received funding to her institution to conduct clinical trials related to maternal immunization and epidemiology from Novavax, Janssen, Glaxo Smith Kline, the US National Institutes of Health and the US Centers for Disease Control and Prevention. E.P.S. has worked as a consultant for Sanofi on immunization projects not related to this study. She has received funding to her institution from vaccine manufacturers to conduct clinical research. I.B.Y. has received funding from Center for Childhood Infections and Vaccines at Emory University and Children’s Healthcare of Atlanta. I.B.Y. has received funding to her institution to conduct clinical research from BioFire, MedImmune, Regeneron, PaxVax, Pfizer, GSK, Merck, Novavax, Sanofi-Pasteur and Micron. J.P.B. has received funding to his institution to conduct clinical research from MedImmune, Pfizer, GSK, Merck, Novavax, Sanofi-Pasteur and Seqirius. C.E.J. has worked as a consultant for MSD, Sanofi and Pfizer on maternal immunization projects not related to this study. She has received funding to her institution to conduct clinical trials from vaccine manufacturers. The other authors have no conflicts of interest to disclose.