Efficacy and Feasibility of SMS m-Health for the Detection of Adverse Events Following Immunisation (AEFIs) in Resource-Limited Setting-The Zimbabwe Stimulated Telephone Assisted Rapid Safety Surveillance (Zm-STARSS) Randomised Control Trial

Introduction: The mHealth active participant centred (MAPC) adverse events following immunisation (AEFI) surveillance is a promising area for early AEFI detection resulting in risk minimisation. The Zimbabwe stimulated telephone assisted rapid safety surveillance (Zm-STARSS) randomized controlled trial (RCT) sought to evaluate the efficacy and feasibility of AEFI detection using a short message service (SMS) and computer assisted telephone interview (CATI) approach.Method: A multicentre Zm-STARSS RCT enrolled consented adults or children vaccinees guardians receiving vaccines, including COVID-19 vaccines, at study sites. At enrolment study participants were randomised to either SMS-CATI group or control group. SMS prompts were sent on days 0-2 and 14 post-vaccination to SMS-CATI group to ascertain if a medical event following immunisation (MEFI) had occurred. However, no SMSs were sent to the control group. SMS-CATI group who responded 'Yes' to SMS prompts were interviewed by research staff who completed a CATI to determine if an MEFI/AEFI had occurred whilst an AEFI in control group was determined from passive AEFI surveillance. Primary outcome was the AEFI detection rate in the SMS-CATI group versus control group.Results: A total of 704 (31%) participants responded to the SMS prompts, with 75% (528/704) indicating 'No' and 25% (176/704) 'Yes' to experiencing a MEFI. However, 31% (55/176) who responded “Yes” did not complete a CATI survey, but 69% (121/176) did; and 64% (77/121) of these indicated negative to AEFI experience whilst 36% (44/121) were affirmative. No AEFIs reported in control group. Zm-STARSS showed promising results in that the AEFI detection rate using SMS-CATI was 2% (44/2280) on an intention to treat cohort.Conclusion: Despite the low SMS response/CATI completion rate, Zm-STARSS study demonstrated that SMS MAPC system improves AEFI detection compared to passive AEFI surveillance. We recommend cost-effective multi-channel digital approaches for holistic pharmacovigilance to improve AEFI detection in LMICs for vaccines.