In February 2017, MEDLINE, Scopus, and Web of Science, as well as three health organisation websites - The Communication Initiative, TechNet-21, and PATH - were searched to identify mHealth intervention studies on vaccination uptake in 21 countries. The aim of this study was to conduct a systematic review of the available literature on the use of mobile health (mHealth) to improve vaccination in low- and middle-income countries with large numbers of unvaccinated children. Given that nearly 100% of the world's population lives within reach of a mobile phone signal and that mobile technology is widely used to improve health communication, mHealth interventions might be used to increase coverage. This is an issue considering that an estimated 18.7 million infants worldwide did not receive routine vaccinations such as the DPT3 (diphtheria) vaccine in 2014, and over 60% of these children live in just 10 LMIC.
Ten peer-reviewed studies and 11 studies from white or gray literature were included. Nine took place in India, three in Pakistan, two each in Malawi and Nigeria, and one each in Bangladesh, Zambia, Zimbabwe, and Kenya. In total, 10 peer-reviewed studies and 7 white or gray studies demonstrated improved vaccination uptake after interventions ranging from SMS (short message service, or text) messages sent to families to remind and encourage them to take their children to the health centre for vaccinations, to using mobile phones to record which settlements have been covered by vaccination campaigns, to mobile phone apps helping health workers to update and access relevant data to facilitate vaccination campaigns.
However, some studies reported no improvement upon intervention. A study from Pakistan found low response rates to SMS messages about vaccinations, even when a financial reward was attached. In these countries, generally, women are 21% less likely to own a mobile phone than men (increasing to 37% in Asia). As women are the primary caregivers to children, this may impact mHealth vaccination interventions. Furthermore, two-thirds of illiterate adults are women, which can further reduce the effectiveness of SMS messages. In households where the father owns the mobile phone, it is imperative that the father is engaged in the project.