METHODS: Parents of all children below five years, vaccinated according to the Australian National Immunisation Schedule between November 2011 and June 2015, were sent an SMS three days post vaccine administration to ask if the child had experienced a suspected vaccine reaction. Affirmative replies triggered a follow up SMS requesting details of any possible reactions via a link to a survey that could be completed on a smartphone. Rates of reported AEFI including fever, headache, fatigue, rash, vomiting, diarrhea, rigors, convulsions, and local reactions were calculated by age and vaccine type.
RESULTS: Overall, possible vaccine reactions were reported for 239 (8.2%; 95% CI 7.2%—9.2%) of 2,898 vaccination visits. A significantly greater proportion of AEFI, mostly local reactions, occurred following administration of diphtheria-tetanus-pertussis-poliomyelitis vaccine at 4 years of age (77/441 [17.5%]; 95% CI 13.9%—21.0%) compared to the vaccinations given at 2–18 months (p<0.001). Across all time points, local reactions and fatigue were the most frequently reported AEFI.
CONCLUSIONS: Automated SMS-based reporting can facilitate sustainable, real-time, monitoring of adverse reactions and contribute to early identification of potential vaccine safety issues. This is critical in maintaining public confidence in the safety of vaccines. Further work should focus on establishing baseline profiles of vaccines in use beyond current post-marketing surveillance.