SMS-Reminder for Vaccination in Africa: Research from Published, Unpublished and Grey Literature

"Immunization protects your child against killer diseases such as polio, whooping cough.. You are reminded that the vaccination appointment will be due in X days' time from today."

One reason for missed vaccination in children in Africa is poor communication between mothers and health workers, which can lead to a lack of knowledge on vaccination, failure to adhere to the vaccination schedule, or lack of proper service or lack of vaccines on the day of vaccination. One strategy that has been used to improve the flow of information is short messaging service (SMS), or text message, vaccine reminders; more than 40 published studies in the Cochrane Database of Systematic Reviews (CDSR) from different regions of the world have proven the effectiveness of this approach. It is hoped that the present review of all studies of SMS-based vaccine reminders in Africa can help inform health practices in the African setting, where mobile phone ownership has been surging rapidly, with some countries achieving more than ten-fold increase in ownership from 2002 to 2014.

This article summarises 5 published articles on the effect of SMS-reminder systems for immunisation in Africa, 1 to-be-published article on the effect of an SMS-reminder system for immunisation in Africa, and 1 unpublished article on an SMS-reminder system for Vitamin A supplement. While 3 studies only focus on SMS reminder system as a sole intervention, with no reminder system as the control, 4 studies added other forms of intervention alongside SMS reminder system, either together or as a combined intervention, or as another monitored intervention in itself.

In short, from the 7 studies done on SMS vaccine reminders in Africa, all have shown marked improvements in the different metrics for vaccination, whether it is through the increase in vaccination coverage (Gibson et al., Bangure et al., Thiaw et al.), decrease in dropout rates (Haji et al.), increase in completion rate (Brown et. al., Eze, Schlumberger et al.), or decrease in delay for vaccination (Bangure et al., Haji et al., Schlumberger et. al.). Eze has shown that the cost per children for using SMS reminder is much lower than home visit, a current method of vaccination reminders in many African countries. A study by Thiaw et al. found that when comparing the intervention group, where SMS and phone call reminders were the main source of information, with the control group, where social mobilisation and health worker communication are the main source of information on Vitamin A supplement, the uptake of Vitamin A is still greater in the intervention group.

All studies used different software to create this SMS reminder platform for immunisation. Rapid SMS, a software developed by the United Nations Children's Fund (UNICEF), is described here as flexible and open-sourced. Rapid SMS and its successors, RapidPro and Textit, could become a more common foundation to build a system on in the future.

Literacy was shown to be an issue in SMS reminder system in 2 studies. A few suggestions include keeping the message simple, using automatic voice messages or calls, or instructing the mothers to ask a literate community member to explain the message. Another issue that the studies faced frequently was the mobile phone number change, which causes the investigator to lose track of the registered mother . In Africa, phone number changes happen frequently due to unreliability of the telecommunication services. Therefore, the SMS-reminder system must have a built-in system for mothers to update their phone numbers.

In conclusion: "Although the studies reviewed showed that SMS reminder system is undisputedly a highly qualified tool for increasing vaccination uptake, the system itself is not the sole factor to be considered when trying to improve vaccination status. Literacy, movements of the population, health facilities, and remoteness of the area all play a part to affect vaccination of the population. Policy efforts should be put to address these areas where technology can only play a minor role. However, as it stands, SMS reminder for vaccination has proven to be effective in multiple control trials and pilot studies done in Africa."