Problem: COVID-19 is the #8 and influenza and pneumonia the #9 leading causes of death among children.
Both COVID-19 and influenza vaccines are on the CDC recommended vaccine schedule for children and
adolescents and both are effective against severe disease. However, coverage rates for both vaccines remain
low or are dropping. Vaccine reminders are widely recommended with text messaging, as a single-method
reminder, having the largest benefit. However, behaviorally-informed COVID-19 vaccine text messages have
not been tested in a pediatric population. Additionally, while COVID-19 and influenza vaccination are going to
be due at the same time it is not known how COVID-19 and influenza vaccination reminders will interact.
We propose a pragmatic Hybrid Type 2 effectiveness/implementation trial with national scope vital to
understanding the effectiveness and implementation of COVID-19 and influenza text message reminders
across parents with varied backgrounds and whose children are cared for in diverse pediatric primary care
practice settings. AIM 1. To compare the effectiveness of behaviorally informed text message reminders
versus usual care on timely receipt of a needed COVID-19 or influenza vaccine dose in a diverse pediatric
primary care population. AIM 2. To compare the effectiveness of two implementation strategies on timely
receipt of each vaccination: combined COVID-19 and influenza vaccine reminders versus COVID-19 or
influenza reminders alone. AIM 3. To assess parental and child characteristics that modify text message
effectiveness. AIM 4. To identify contextual factors, facilitators and barriers to implementation and
sustainability of text messages for influenza and COVID-19 vaccination in a diverse pediatric population.
Methods: This multi-site trial will include 40,000 parents of 6 month-17-year-old children who are due for both
a COVID-19 and influenza vaccine. Practices will be recruited through the American Academy of Pediatrics
national Pediatric Research in Office Settings (PROS) network. In season 1, children will be randomized into 4
arms: combined COVID-19 and influenza vaccine text message reminders, COVID-19 reminders alone,
influenza reminders alone, and no reminders. Messages will be managed by the research team. The primary
outcome for Aim 1 will be timeliness of vaccine receipt (COVID-19 and/or influenza separately) from trial start.
Aim 2 will compare the implementation strategy of single vs combined reminders assessing whether combining
reminders for both vaccines leads to additive (or synergistic) or negative effects. Season 2 will be a replication
study. In season 3, practices will implement messages on their own. Using a mixed-methods approach, we will
use the RE-AIM framework in combination with the Consolidated Framework for Implementation Research
(CFIR) to understand factors shaping implementation success. On a national scale, understanding the
effectiveness and implementation of influenza and COVID-19 vaccine text message reminders among a
diverse pediatric population will provide key information to multiple stakeholders to bolster vaccine receipt.
