BackgroundInvasive pneumococcal disease is one of the most important vaccine-preventable diseases threatening the adult community due to missed opportunities for vaccination. This study compares the effect of three different types of patient reminder system on adulthood Streptococcus pneumoniae immunization in a primary care setting. MethodsThe study targeted patients aged 40 and older eligible for pneumococcal vaccine, but did not receive it yet (89.5% of 3072 patients) based on their electronic medical records in a family medicine center in Beirut. The sample population was randomized using an automated computer randomization system into six equal groups, receiving short phone calls, short text messaging system (sms-text) or e-mails each with or without patient education. Each group received three identical reminders spaced by a period of four weeks. Documentation of vaccine administration was then added to the longitudinal electronic patient record. The primary outcome was the vaccine administration rate in the clinics. ResultsOf the eligible patients due for the pneumococcal 23-polyvalent vaccine, 1380 who had mobile phone numbers and e-mails were randomized into six equal intervention groups. The various reminders increased vaccination rate to 14.9%: 16.5% of the short phone calls group, 7.2% of the sms-text group and 5.7% of the e-mail group took the vaccine. The vaccination rate was independent of the age, associated education message and the predisposing condition. ConclusionUse of electronic text reminders via e-mails and mobile phones seems to be a feasible and sustainable model to increase pneumococcal vaccination rates in a primary care center.