Example of Immunization with a Reaction

{
  "resourceType" : "Immunization",
  "id" : "reaction",
  "identifier" : [{
    "system" : "urn:ietf:rfc:3986",
    "value" : "urn:oid:1.3.6.1.4.1.21367.2005.3.7.1234"
  }],
  "status" : "completed",
  "vaccineCode" : {
    "coding" : [{
      "system" : "http://hl7.org/fhir/sid/cvx",
      "code" : "175"
    }],
    "text" : "Rabies - IM Diploid cell culture"
  },
  "manufacturer" : {
    "reference" : {
      "reference" : "Organization/hl7"
    }
  },
  "lotNumber" : "PPL909K",
  "expirationDate" : "2023-01-21",
  "patient" : {
    "reference" : "Patient/example"
  },
  "encounter" : {
    "reference" : "Encounter/example"
  },
  "occurrenceDateTime" : "2021-09-12",
  "primarySource" : true,
  "location" : {
    "reference" : "Location/1"
  },
  "site" : {
    "coding" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/v3-ActSite",
      "code" : "LA",
      "display" : "left arm"
    }]
  },
  "route" : {
    "coding" : [{
      "system" : "http://terminology.hl7.org/CodeSystem/v3-RouteOfAdministration",
      "code" : "IM",
      "display" : "Injection, intramuscular"
    }]
  },
  "doseQuantity" : {
    "value" : 5,
    "system" : "http://unitsofmeasure.org",
    "code" : "mg"
  },
  "performer" : [{
    "function" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/v2-0443",
        "code" : "OP"
      }]
    },
    "actor" : {
      "reference" : "Practitioner/example"
    }
  },
  {
    "function" : {
      "coding" : [{
        "system" : "http://terminology.hl7.org/CodeSystem/v2-0443",
        "code" : "AP"
      }]
    },
    "actor" : {
      "reference" : "Practitioner/example"
    }
  }],
  "note" : [{
    "text" : "Notes on adminstration of vaccine"
  }],
  "reason" : [{
    "reference" : {
      "reference" : "Observation/example"
    }
  }],
  "isSubpotent" : false,
  "reaction" : [{
    "date" : "2021-09-12",
    "manifestation" : {
      "reference" : {
        "reference" : "Observation/example2"
      }
    },
    "reported" : false
  }]
}