Daily Archives: 15 October 2012

Do Text Messaging Interventions Affect Vaccination Rates?

There are many benefits to increasing the national average of vaccinations, especially for influenza. Influenza results in high costs medically via outpatient appointment and hospitalizations, and also high indirect costs, such as days of work lost due to illness. Nationally, influenza vaccinations rates are quite low. However, low-incomes families tend to have even lower vaccination rates. During the 2010-2011 influenza season, a randomized controlled trial was developed to test whether text message vaccination reminders to parents of low-income families would increase the likelihood that their children would get vaccinated. Children and adolescents were targeted because they tend to transmit influenza “to those at highest risk for severe disease,” however, the parents of the children would be the ones receiving the text message reminders. The primary analysis group was made up of predominately low-income and minority families. The parents received 5 weekly, automated texts in their native language (either English or Spanish). The first 3 messages addressed myths about vaccinations, vaccination safety, and reminded the parents of the severity of influenza. The last 2 messages gave the dates for Saturday vaccination clinics.


  1. 43.6% of children in the group that received the text reminders were vaccinated as opposed to the 39.9% who received the traditional landline or mail reminders
  2. The text message system could be linked up to pre-exisiting immunization databases such as EzVac.
  3. Text messaging is extremely cost effective. More then 23,000 messages were sent during the study for only $165.
  4. Text messaging is more reliable because cell phone numbers tend to be more stable then home addresses or landline numbers. Additionally, text messaging is better for more urgent notifications because it is sent/received immediately.


  1. This study did not address “competing priorities and barriers” to vaccinations. This could range any where from lack of funds to busy parent work schedules. Addressing these other issues could raise costs.
  2. Due to the randomization of the sample, parents with multiple children could have had one child in the intervention group while the other was not, therefore the child outside the intervention group may have received a vaccine when he or she otherwise would not have.
  3. The study targeted a low income, urban community. Therefore, the results may not be applicable to other communities or demographics.
  4. Due to overcrowding concerns at the clinics, not every family was alerted of every clinic date. This could have led to underestimated effects of the text message reminders.

Overall, I believe that text message reminders do, in fact, help parents remember to get their children vaccinated. I also think that addressing misconceptions and stereotypes about vaccinations in the first three text messages was very key. However, I do think that this study was very simplistic and left many variables unaddressed. For example, I think a study should look into the role that schools play in vaccination rates. School is where the target population of children and adolescents spend most of their time. Therefore, school boards should take a more vested interest in offering vaccination schedules during school hours because I would imagine that most of these low-income parents do not have many free Saturdays to take their children to the free clinics. Additionally, the school would save lost wages for teachers who need to take sick days due to an influenza outbreak among students. Perhaps there could be a program that requires all students to be vaccinated at school unless specifically instructed otherwise by a parent.


Kharbanda et. al, Text4Health 

Stockwell et. al, Text4Health