Feasibility of Text Message Influenza Vaccine Safety Monitoring During Pregnancy

Abstract

Introduction: The feasibility and accuracy of text messaging to monitor events after influenza vaccination throughout pregnancy and the neonatal period has not been studied, but may be important for seasonal and pandemic influenza vaccines and future maternal vaccines.

Methods: This prospective observational study was conducted during 2013-2014 and analyzed in 2015-2016. Enrolled pregnant women receiving inactivated influenza vaccination at a gestational age <20 weeks were sent text messages intermittently through participant-reported pregnancy end to request fever, health events, and neonatal outcomes. Text message response rates, Day 0-2 fever (≥100.4°F), health events, and birth/neonatal outcomes were assessed.

Results: Most (80.2%, n=166) eligible women enrolled. Median gestational age was 8.9 (SD=3.9) weeks at vaccination. Response rates remained high (80.0%-95.2%). Only one Day 0-2 fever was reported. Women reported via text both pregnancy- and non-pregnancy-specific health events, not all associated with medical visits. Most pregnancy-specific events in the electronic medical record (EMR) were reported via text message. Of all enrollees, 84.9% completed the study (131 reported live birth, ten reported pregnancy loss). Two losses reported via text were not medically attended; there was one additional EMR-identified loss. Gestational age and weight at birth were similar between text message-reported and EMR-abstracted data and 95% CIs were overlapping for proportions of prematurity, low birth weight, small for gestational age, and major birth defects, as identified by text message-reported versus EMR-abstracted plus text message-reported versus EMR-abstracted data only.

Conclusions: This study demonstrated the feasibility of text messaging for influenza vaccine safety surveillance sustained throughout pregnancy. In these women receiving inactivated influenza vaccination during pregnancy, post-vaccination fever was infrequent and a typical pattern of maternal and neonatal health outcomes was observed.

Conflict of interest statement

M.S. Stockwell is a co-investigator but receives no financial support for an unrelated, investigator-initiated grant from the Pfizer Medical Education Group. The other authors have no conflicts of interests or financial disclosures.

Copyright © 2017 American Journal of Preventive Medicine. All rights reserved.

Figures

Figure 1.

Text message response rates by day post-vaccination and response types. (A) Day 0–2 responses to text messages assessing fever; (B) Day 7–42 responses to text messages assessing short-term adverse events temporally associated with vaccination; (C) Day 70–245 responses to text messages assessing health events through the end of pregnancy, and pregnancy and neonatal outcomes. Note: Response rates end on Day 245 due to having fewer than five participants from Day 252–259. Denominator includes all women who had not yet reported a pregnancy outcome who were still within 2 weeks of their estimated due date.