1. Enrollment Form: At the child's first visit to the center, the field worker will note the name and age of the child along with the immunizations received during the visit in addition to basic demographic information in the enrolment form. This information, along with basic biographic information is recorded routinely by vaccinators in their government issued permanent medical registers. An immunization visit typically takes between 10 and 15 minutes, not including any time spent waiting to be seen by the vaccinator.