Feasibility of Text Message Influenza Vaccine Safety Monitoring During Pregnancy.

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.