Immunization

The Immunization resource records the administration of vaccines. It tracks which vaccines were given, when, and by whom.

API convention: patient, encounter, and location references are sent as flat string id fields (patientId, encounterId, locationId). Performer references use the standard FHIR reference shape. All resource ids are raw UUIDs (v4).

Creating an Immunization Record

curl -X POST https://api.esus.health/fhir/Immunization \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/fhir+json" \
  -d '{
    "status": "completed",
    "patientId": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
    "vaccineCode": {
      "coding": [{
        "system": "http://hl7.org/fhir/sid/cvx",
        "code": "208",
        "display": "COVID-19 vaccine, mRNA, spike protein, LNP-S"
      }]
    },
    "occurrenceDateTime": "2026-04-21",
    "primarySource": true,
    "performer": [
      {
        "actor": {
          "reference": "Practitioner/a7b1c2d3-e4f5-6789-abcd-ef0123456789",
          "display": "Dr. Anna Lopez"
        }
      }
    ]
  }'

Immunization Statuses

Status	Meaning
`completed`	Vaccine was administered
`entered-in-error`	Erroneous record
`not-done`	Immunization not performed

Important Fields

Field	Description
`patientId`	The patient who received the vaccine (UUID)
`vaccineCode`	The vaccine administered (CVX or SNOMED codes)
`occurrenceDateTime`	Date of administration
`primarySource`	Did the record come from the provider who administered?
`performer[]`	Who administered the vaccine
`lotNumber`	Vaccine lot number
`site`	Body site of administration
`route`	How it was administered (oral, IM, etc.)
`isSubpotent`	`true` if the dose is considered subpotent

Protocol Applied

{
  "protocolApplied": [
    {
      "doseNumber": 1,
      "targetDisease": [
        {
          "coding": [{
            "system": "http://snomed.info/sct",
            "code": "840539006",
            "display": "COVID-19"
          }]
        }
      ]
    }
  ]
}

doseNumber identifies this dose within a multi-dose series; the API accepts integers or strings.

Why Track Immunizations

Immunization records are essential for:

Patient safety — avoid vaccine duplication
Public-health tracking
School and travel requirements
Reminders for upcoming doses