Participants are uniquely identified by *subject_id*. Each *date* column shows the date of the respective event; note that a random date offset has been applied to all dates to de-identify the data. Where present, *infant_age* is a derived column computed from *dob* in the infant enrollment table.

* Enrollment:
Initial study enrollment questionaire, with separate tables for mothers and infants. Tables contain subject demographic and health information. Note that all subjects shown here also met study enrollment criteria.

* Study visit:
One row per subject clinic visit. Separate rows for mother and infant are denoted by the *parent* column (T=mother, F=infant). Visit type is indicated by the *type* column, where "baseline" visits correspond to study enrollment.

* Vaccination:
One row per vaccination. Most vaccinations have a corresponding study visit (see above). *nshot* is a computed column showing the number of vaccinations the subject has received to-date (including this one).