Vaccine Health Literacy Related Text Message Reminders to Increase Receipt of Second Dose of Influenza Vaccine for Young, Low Income, Urban Children

Influenza remains a potentially significant and largely preventable source of morbidity and
mortality, yet vaccine coverage is low. Young children are at particular risk for
underimmunization because they may need to receive 2 doses in a current season. Even among
those young children that initiate vaccination, only 40% receive the important second dose,
yet one dose does not confer adequate protection. Low-income, urban children may be at
particular risk of not receiving two doses. While traditional mail and phone immunization
reminders notifying families that a vaccine is due have had limited efficacy in low-income,
urban populations, we have demonstrated the success of using text messages. Comparing the
effectiveness of different forms of reminders on receipt of this critical second dose of
influenza vaccine has not been studied. Besides failure to remember to return for subsequent
doses, receipt of 2 doses of influenza vaccine in a season can be affected by limited health
literacy regarding influenza vaccination, particularly associated with understanding the
need for a second dose since not all children require it. Text messaging offers the ability
to combine health literacy promoting information and reminders in a scalable, efficient
manner for populations at high risk for underimmunization, limited health literacy, and
influenza spread. Therefore, the purpose of this study is to determine whether the provision
of interactive vaccine health literacy-promoting information in text message vaccine
reminders improves receipt and timeliness of the second dose of influenza vaccine within a
season for underserved children in need of two doses.