The goal of this clinical trial is to assess the effectiveness of enhanced email reminders in improving vaccine coverage at the 12-month visit in CANImmunize app users. The main questions it aims to answer are:

• Do enhanced email reminders improve coverage of the 12- month dose of the pneumococcal vaccine and the timely completion of its immunization series at the 12-month's visit in CANImmunize app users?
• What are the predictors of predictors of timely completion of the 12-month's series of pneumococcal vaccines in the CANImmunize app users?

Participants will be randomized to either receive enhanced reminder/recall materials via email or the standard CANImmunize notifications. Researchers will compare the enhanced reminder group to the standard notification group to see if there is a difference in vaccine coverage at the 12-month visit.

Inclusion Criteria

To be included in the study, CANImmunize account holders must have:

• Enabled the reception to receive emails from CANImmunize, and
• Record(s) for an infant aged between 10- and 11-months, who have already received the earlier doses of the pneumococcal vaccine in accordance with their provincial/territorial routine immunization schedule.

Exclusion Criteria

• The account holder (parent, or guardian of the child) has an inactive or undelivered email address, or
• No record(s) for an infant aged 10- and 11-months, or
• The record for the 10- or 11-month-old indicates that he/she has not received the prior pneumococcal vaccine doses.