RESUMEN
Background. The timely completion of the childhood immunisation schedule for children under the age of 1 year by caregivers is key to reducing the high morbidity and mortality of vaccine-preventable diseases among infantsglobally.Objective. To determine the ownership of mobile phones among caregivers of children under the age of 1 year, their knowledge about immunisation service delivery and willingness to receive childhood immunisation schedule reminder messages in Ondo State, south-western Nigeria.Method. A descriptive cross-sectional study using semi-structured interviewer-administered questionnaires was conducted with 615 caregivers of infants, who brought their children to clinics conducting immunisation in 24 health facilities in rural, semi-urban and urban settlements in Ondo State in December 2014.Results. The mean (standard deviation, SD) age of respondents was 28.49 (6.01) years, 76.7% were Yoruba, 91.4% were married and living with their spouses and 4.2% were single. Mobile phone ownership was 74.5% among rural-based respondents, and 95.8% among urbanbased.Forty-six percent of the respondents had good knowledge of immunisation, vaccine-preventable diseases and vaccination schedules,while 27.5% had poor knowledge. The majority of the respondents (99.7%) were willing to receive childhood immunisation reminder messages on their mobile phones. About 50% of the respondents preferred to receive reminder messages at any time, rather than specific times. The most preferred language for reminders was English (54.5%). Residing in an urban area and having post-secondary education were predictors of mobile phone ownership.Conclusion. The high mobile phone ownership level, and the willingness of caregivers of infants in this study area to receive immunisation schedule reminder messages, is encouraging, and should be optimised to improve routine immunisation uptake. However, caregivers of infants in rural areas need to be provided with mobile phone support, and trained in their usage in order to benefit from such an intervention in childhood immunisation