Development and Pilot Testing of a Text Message Vaccine Reminder System for Use during an Influenza Pandemic

"The more you can remind people the better, and cell phones are an easy way to do it." - participant

One method shown to increase vaccine series completion and improve immunisation rates is use of short-message-service (SMS) messaging (i.e., texts) to facilitate communication with patients about health interventions. To prepare for a hypothetical two-dose influenza pandemic vaccine campaign and promote dose-series completion and correct dosing intervals, the Centers for Disease Control and Prevention (CDC) and its partners developed a prototype patient-centred, text-message-based system to remind people who receive a first dose of pandemic influenza vaccine to receive the second dose. This article describes the study and shares its results.

Taking advantage of the high prevalence of cell phones in the United States (US), the system sent second-dose text message reminders and hyperlinks to educational information. Flu Vax Alert was pilot tested from November 2015 to April 2016 among graduate public health students enrolled at 4 US universities.

Flu Vax Alert prompted participants to indicate which combination of vaccine and adjuvant (e.g. vaccine A/adjuvant A, etc.) they received at their first dose and when it was given. Throughout the recommended 21-day interval between doses, participants were sent texts reminding them of the required timing and vaccine/adjuvant combination for their second dose. Messages also included a link to HealthMap Vaccine Finder, a free web-based tool for finding vaccination locations that was used to simulate pandemic vaccination locations. Some participants were instructed to reply to the text-message reminder system indicating they had received the second vaccine dose. Upon receiving a two-dose completion message, the system sent a final text message that included a link to an anonymous 11-item survey where participants could provide feedback on their experience with the system. Participants who did not indicate receiving the second dose were sent a link to the survey after they received the maximum number of messages.

Among 59 volunteers who pilot tested the system and completed a survey, 57 (92%) felt the system would be helpful during a pandemic. Forty (68%) respondents felt the information included in the messages was informative. Information that respondents reported would be helpful to add included tips on how to stay healthy during a pandemic (n = 30, 51%), information on potential adverse reactions from the vaccine (n = 27, 46%), and additional links to more resources for information (n = 28, 47%). Over half of the survey respondents felt that the messages sent by the system were repetitive.

The researchers note that, in a pandemic, the number of messages that an individual deems "the right amount" or "too much" will vary. Health departments or vaccine providers developing their own text message reminder systems could incorporate a function where the participant can select how frequently they would like to receive information. However, adding such a feature would increase the complexity and may increase the cost to operate the system.

In addition to considering the number of messages, organisations conducting pilot tests in the future should consider the inclusion of a wider variety of pandemic information. According to the researchers, participants' desire for actionable information must be balanced with the need to include enough information to maximise second dose uptake and provisions to avoid message fatigue.

Only eight (14%) respondents felt that the language in the messages was "persuasive", perhaps because messages were generic so as to be applicable to diverse populations. In complementing a text-message-based reminder system, efforts could be made to personalise recommendations, such as providers reminding patients face to face about the necessity for a second dose.

In conclusion: "Pre-pandemic communication and health education planning by public health programs and their partners should take into account the potential difficulty of ensuring dose-series completion for a two-dose pandemic influenza vaccine." The above study demonstrated how SMS reminders could be effectively used in those efforts. "Communications campaigns conducted by the CDC before and during a pandemic will also serve to reiterate the critical need for patients to receive the recommended number of vaccine doses to be protected from infection."