Vaccination is a cost-effective strategy for conferring immunity against a host of preventable diseases, however, rates of timely childhood vaccinations remain inadequate in resource-limited settings. We propose to evaluate the feasibility and efficacy of mHealth-assisted conditional cash transfers as a means of overcoming individual barriers to timely vaccinations. The study will form the basis for a pragmatic randomized controlled trial of the efficacy and cost-effectiveness of mHealth reminders and conditional cash transfers for improving rates of timely vaccinations among young children.

Vaccination is one of the most cost-effective strategies for conferring immunity against a host of preventable diseases. The World Health Organization estimates that over 2.5 million child deaths are prevented annually worldwide due to vaccination efforts. Infants must receive all recommended vaccinations in a timely manner to be fully protected from deadly infectious diseases such as tuberculosis, diphtheria, pertussis and polio. A large body of evidence has shown that children living in socio-economically disadvantaged backgrounds are more likely to be vaccinated late, or not at all, compared to their counterparts from wealthier and more educated families. While Tanzania has successfully achieved high national vaccination coverage, there remain substantial regional variations. In this proposal we seek to evaluate the feasibility of combining two emerging types of interventions - mHealth and conditional cash transfers - to overcome individual barriers to timely vaccinations. Researchers at Duke University and Tanzania's National Institute of Medical Research (NIMR) will collaborate to evaluate whether mobile phone (mHealth)-based vaccination reminders, combined with a financial incentive scheme for families with young children, may result in improved vaccination coverage and timeliness. The specific aims of the proposal are to (1) conduct formative research to identify locally relevant client-side and provider-side barriers to timely vaccinations; (2) develop an mHealth system to facilitate and monitor timely vaccinations and conduct surveys with late-stage pregnant women to derive willingness-to-accept estimates and a feasible incentive structure; and (3) assess the efficacy of a combination intervention consisting of mHealth reminders and conditional cash transfers for improving the rates and timeliness of vaccinations among infants in their first 6 months of life. Qualitative follow-up surveys with providers and a subset of clients will assess barriers to the acceptability and scalability of an mHealth supported conditional cash-transfer intervention for timely vaccination. The study will be implemented with support from Tanzania's Ministry of Health and Social Welfare Immunization and Vaccine Development Programme. The results of the proposed study will form the basis for a pragmatic randomized controlled trial of the efficacy and incremental cost-effectiveness of mHealth reminders and conditional cash transfers as means of improving timely vaccinations of young children.

Inclusion Criteria:

• Pregnant, last trimester
• Access to mobile phone

Exclusion Criteria:

• Cognitive impairment
• Unwillingness to receive study-related information and reminders via mobile phone

Data from the proposed study will be stored in a data repository; this data will be de-identified so that they cannot be linked back to individuals. Investigators wishing to use study data to answer new research questions may submit data analysis concept proposals for consideration by the Principal Investigators. The Principal Investigators will review the proposal and will provide those submitting scientifically rigorous and promising proposals access to the data repository to address their research questions. This will ensure that the data resources of the proposed study will provide the greatest possible benefit to the scientific community.

Of 412 participants enrolled, 14 were disenrolled due to maternal death (n=1), child death (n=11), or withdrawal (n=2), leaving an initial sample of 398 participants. 79 participants were lost to follow-up. Baseline data were lost (due to tablet failure) for 6 participants. The effective enrollment into the trial was N=313. N=310 had valid data on study outcomes and per-protocol assignment to study arms.

Through study completion, an average of 1 year.