Messaging Impact on Parental Acceptance of RSV Immunization in the Emergency Department

Across the globe, an infant’s first exposure to respiratory syncytial virus (RSV) is the most common cause for hospitalization. Approximately 25% of infants go un-immunized against RSV annually. In recent years, distrust in the public health sector has been associated with declining parental immunization confidence. Therefore, the objective of this study was to evaluate the impact of RSV monoclonal antibody (mAb) specific messaging on parental immunization confidence in the emergency department (ED).

This study was a 4-pronged randomized control trial. Caregivers of patients between aged 0-8 months old presenting to the ED between 10/1/2025 and 12/14/2025 were eligible. Critically ill patients, leveled trauma patients, and patients without a consenting legal guardian or English speaking caregivers were excluded from this study. Children presenting to the emergency department with suspected non-accidental trauma were also excluded from this study. Participants who were not immunized against RSV were assessed for their intent to immunize against RSV. Participants were then randomized to receive one of four immunization messages and finally re-assessed for intent to immunize their child against RSV. Messages consisted of the exact same language offering RSV mAb while in the ED and described the complications of being infected with RSV. The messages differed in the term used to describe the immunization in order to measure the impact of the terminology that providers use to describe vaccines to caregivers. Four iterations were used: vaccine, immunization, antibody, and medicine.

Of the 49 enrolled participants, 14 (28.6%) were initially non-intent. The greatest impact was observed when messaging consistently used the term “vaccine,” with 1 of 5 participants in this group (20%) shifting from non-intent to intent. In comparison, no participants in the “immunization”, “antibody”, or “medicine” groups demonstrated a change from non-intent to intent.

Our findings show that approximately 1 in 4 caregivers are not intent on immunizing their child against RSV. Targeted messaging that clearly identifies the intervention as a vaccine and emphasizes preventable RSV complications demonstrates the highest potential for improving caregiver vaccine acceptance in the emergency department.