Id: IMMZD5DTYellowFeverContraindications Url: IMMZ.D5.DT.Yellow fever contraindications Version: 0.2.0 Title: IMMZ.D5.DT.Yellow fever contraindications Status: draft Type: system: http://terminology.hl7.org/CodeSystem/plan-definition-type code: eca-rule Date: 2026-03-03 13:07:11+0000 Publisher: WHO Description: IMMZ.D5.DT.Yellow fever contraindications IMMZ.D5.DT.Yellow fever contraindications Knowledge Capability: computable Related Artifacts: References WHO recommendations for routine immunization - summary tables (January 2025) Libraries: IMMZD5DTYellowFeverContraindicationsLogic Actions: Check for contraindications before administering the vaccine(s) due: Contraindication for Yellow fever immunization If: Applicability: Yellow fever vaccination is contraindicated (Yellow fever vaccination is contraindicated) Then: Definition: IMMZD5DTMR Dynamic Values: id: (Draft Medication Request ID for Yellow fever dose) medication: (Concept { codes: { Code { system: 'http://smart.who.int/immunizations/CodeSystem/IMMZ.Z', code: 'DE23', display: 'Yellow fever vaccines' } }, display: 'Yellow fever vaccines' }) Check for Guidance for the patient regarding IMMZ.D5.DT.Yellow fever contraindications.: Show Guidance for the patient regarding IMMZ.D5.DT.Yellow fever contraindications. If: Applicability: Has Guidance (Has Guidance) Then: Definition: IMMZ.D2.DT.CR Dynamic Values: status: ('active') payload.contentString: (Guidance) category.coding: (Code { system: 'http://terminology.hl7.org/CodeSystem/communication-category', code: 'alert' }) priority: (Code { system: 'http://hl7.org/fhir/request-priority', code: 'routine' })
/** * @dataElement Patient age in months */ define "Current Patient Age In Months": AgeInMonthsAt(Today)
/* @input: Client's age is less than 6 months @pseudocode: Today's date − "Date of birth" < 6 months @code: Client's age is less than 6 months-41 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "Client's age is less than 6 months": Encounter."Current Patient Age In Months" < 6
Yellow fever vaccination is contraindicated Case 1
/* @output: Yellow fever vaccination is contraindicated Case 1 @pseudocode: "Immunization recommendation status" = "Contraindicated" */ define "Yellow fever vaccination is contraindicated Case 1": Encounter."Client's age is less than 6 months"
/* @internal: Potential contraindications observations */ define "Potential contraindications": ([Observation: Concepts."Potential contraindications"]).complete()
CI Severely immunocompromised Observation
/* @internal: Observation for Severely immunocompromised */ define "CI Severely immunocompromised Observation": "Potential contraindications" O where O.value ~ Concepts."CI-Severely immunocompromised"
/* @internal: Observation for Severely immunocompromised */ define "CI Severely immunocompromised Observation": Elements."CI Severely immunocompromised Observation".encounterOrOnBefore(EncounterId, Today)
/* @internal: Condition for Severely immunocompromised */ define "CI Severely immunocompromised Condition": [Condition: Concepts."CI-Severely immunocompromised"]
/* @internal: Condition for Severely immunocompromised */ define "CI Severely immunocompromised Condition": Elements."CI Severely immunocompromised Condition" C where C.prevalenceInterval() includes Today
The client is severely immunocompromised
/* @input: The client is severely immunocompromised @pseudocode: "Potential contraindications" = "Severely immunocompromised" */ define "The client is severely immunocompromised": exists "CI Severely immunocompromised Observation" or exists "CI Severely immunocompromised Condition"
/* @input: The client is severely immunocompromised @pseudocode: "Potential contraindications" = "Severely immunocompromised" @code: The client is severely immunocompromised-60 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "The client is severely immunocompromised": Encounter."The client is severely immunocompromised"
Yellow fever vaccination is contraindicated Case 2
/* @output: Yellow fever vaccination is contraindicated Case 2 @pseudocode: "Immunization recommendation status" = "Contraindicated" */ define "Yellow fever vaccination is contraindicated Case 2": Encounter."The client is severely immunocompromised"
Yellow fever vaccination is contraindicated
/* @output: Yellow fever vaccination is contraindicated @pseudocode: "Immunization recommendation status" = "Contraindicated" */ define "Yellow fever vaccination is contraindicated": "Yellow fever vaccination is contraindicated Case 1" or "Yellow fever vaccination is contraindicated Case 2"
Yellow fever vaccination is contraindicated Guidance
/* @output: Yellow fever vaccination is contraindicated Guidance @guidance = Do not vaccinate client with yellow fever as yellow fever vaccination is contraindicated in client's aged less than 6 months. @guidance = Do not vaccinate client with yellow fever as yellow fever vaccination is contraindicated in severely immunocompromised clients. */ define "Yellow fever vaccination is contraindicated Guidance": case when "Yellow fever vaccination is contraindicated Case 1" then 'Do not vaccinate client with yellow fever as yellow fever vaccination is contraindicated in client\'s aged less than 6 months.' when "Yellow fever vaccination is contraindicated Case 2" then 'Do not vaccinate client with yellow fever as yellow fever vaccination is contraindicated in severely immunocompromised clients.' else '' end
/* @input: Client's age is 6–9 months @pseudocode: 6 months ≤ Today's date − "Date of birth" < 9 months @code: Client's age is 6–9 months-52 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "Client's age is 6–9 months": 6 <= Encounter."Current Patient Age In Months" and Encounter."Current Patient Age In Months" < 9
Clinical judgement is required. Create a clinical note Case 1
/* @output: Clinical judgement is required. Create a clinical note Case 1 @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Clinical judgement is required. Create a clinical note Case 1": Encounter."Client's age is 6–9 months"
/** * @dataElement Patient age in years */ define "Current Patient Age In Years": AgeInYearsAt(Today)
Client's age is more than or equal to 60 years
/* @input: Client's age is more than or equal to 60 years @pseudocode: Today's date − "Date of birth" ≥ 60 years @code: Client's age is more than or equal to 60 years-41 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "Client's age is more than or equal to 60 years": Encounter."Current Patient Age In Years" >= 60
Clinical judgement is required. Create a clinical note Case 2
/* @output: Clinical judgement is required. Create a clinical note Case 2 @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Clinical judgement is required. Create a clinical note Case 2": Encounter."Client's age is more than or equal to 60 years"
/* @internal: Observation for currently pregnant */ define "CI Currently pregnant Observation": "Potential contraindications" O where O.value ~ Concepts."CI-Currently pregnant"
/* @internal: Observation for currently pregnant */ define "CI Currently pregnant Observation": Elements."CI Currently pregnant Observation" O where O.encounter.references(EncounterId) or O.effective.toInterval() starts same day or after Today - 9 months
/* @internal: Condition for currently pregnant */ define "CI Currently pregnant Condition": [Condition: Concepts."CI-Currently pregnant"]
/* @internal: Condition for currently pregnant */ define "CI Currently pregnant Condition": Elements."CI Currently pregnant Condition" C where C.prevalenceInterval() includes Today
define "Pregnancy Status Observation": [Observation: Concepts."Pregnancy status"] O where O.status in { 'final', 'amended', 'corrected' }
define "Pregnant Observation": "Pregnancy Status Observation" O where O.value ~ Concepts."Pregnant"
define "Pregnant Observation": Elements."Pregnant Observation" O where O.encounter.references(EncounterId) or O.effective.toInterval() starts same day or after AsOf - 9 months
/* @input: The client is pregnant @pseudocode: "Potential contraindications" = "Currently pregnant" */ define "The client is pregnant": exists "CI Currently pregnant Observation" or exists "CI Currently pregnant Condition" or exists WE."Pregnant Observation"
/* @input: The client is currently pregnant @pseudocode: "Potential contraindications" = "Currently pregnant" @code: The client is currently pregnant-52 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "The client is currently pregnant": Encounter."The client is pregnant"
Clinical judgement is required. Create a clinical note Case 3
/* @output: Clinical judgement is required. Create a clinical note Case 3 @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Clinical judgement is required. Create a clinical note Case 3": Encounter."The client is currently pregnant"
/* @internal: Observation for Breastfeeding */ define "CI Breastfeeding Observation": "Potential contraindications" O where O.value ~ Concepts."CI-Breastfeeding"
/* @internal: Observation for Breastfeeding */ define "CI Breastfeeding Observation": Elements."CI Breastfeeding Observation".encounterOrOnBefore(EncounterId, Today)
/* @internal: Condition for Breastfeeding */ define "CI Breastfeeding Condition": [Condition: Concepts."CI-Breastfeeding"]
/* @internal: Condition for Breastfeeding */ define "CI Breastfeeding Condition": Elements."CI Breastfeeding Condition" C where C.prevalenceInterval() includes Today
/* @input: The client is lactating @pseudocode: "Potential contraindications" = "Breastfeeding" */ define "The client is lactating": exists "CI Breastfeeding Observation" or exists "CI Breastfeeding Condition"
/* @input: The client is lactating @pseudocode: "Potential contraindications" = "Breastfeeding" @code: The client is lactating-47 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "The client is lactating": Encounter."The client is lactating"
Clinical judgement is required. Create a clinical note Case 4
/* @output: Clinical judgement is required. Create a clinical note Case 4 @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Clinical judgement is required. Create a clinical note Case 4": Encounter."The client is lactating"
Clinical judgement is required. Create a clinical note
/* @output: Clinical judgement is required. Create a clinical note @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Clinical judgement is required. Create a clinical note": "Clinical judgement is required. Create a clinical note Case 1" or "Clinical judgement is required. Create a clinical note Case 2" or "Clinical judgement is required. Create a clinical note Case 3" or "Clinical judgement is required. Create a clinical note Case 4"
Clinical judgement is required. Create a clinical note Guidance
/* @output: Clinical judgement is required. Create a clinical note Guidance @guidance = Check if exceptions to age range is being met, consider risks of vaccination and make a clinical judgement. Vaccine is not recommended for those aged 6–8 months, except during epidemics when the risk of infection with the yellow fever virus is very high. @guidance = Conduct a risk–benefit assessment taking into account the risk of acquiring yellow fever disease, consider risks of potential adverse events following immunization and make a clinical judgement. @guidance = Conduct a risk–benefit assessment since yellow fever is a live vaccine and make a clinical judgement. Pregnant women may be vaccinated during epidemics at the direction of local health authorities. @guidance = Conduct a risk–benefit assessment since yellow fever is a live vaccine and make a clinical judgement. Lactating women should be advised that the benefits of breastfeeding far outweigh alternatives. */ define "Clinical judgement is required. Create a clinical note Guidance": case when "Clinical judgement is required. Create a clinical note Case 1" then 'Check if exceptions to age range is being met, consider risks of vaccination and make a clinical judgement. Vaccine is not recommended for those aged 6–8 months, except during epidemics when the risk of infection with the yellow fever virus is very high.' when "Clinical judgement is required. Create a clinical note Case 2" then 'Conduct a risk–benefit assessment taking into account the risk of acquiring yellow fever disease, consider risks of potential adverse events following immunization and make a clinical judgement.' when "Clinical judgement is required. Create a clinical note Case 3" then 'Conduct a risk–benefit assessment since yellow fever is a live vaccine and make a clinical judgement. Pregnant women may be vaccinated during epidemics at the direction of local health authorities.' when "Clinical judgement is required. Create a clinical note Case 4" then 'Conduct a risk–benefit assessment since yellow fever is a live vaccine and make a clinical judgement. Lactating women should be advised that the benefits of breastfeeding far outweigh alternatives.' else '' end
CI Severe allergic reactions Observation
/* @internal: Observation for Severe allergic reactions */ define "CI Severe allergic reactions Observation": "Potential contraindications" O where O.value ~ Concepts."CI-Severe allergic reactions"
/* @internal: Observation for Severe allergic reactions */ define "CI Severe allergic reactions Observation": Elements."CI Severe allergic reactions Observation".encounterOrOnBefore(EncounterId, Today)
/* @internal: Condition for Severe allergic reactions */ define "CI Severe allergic reactions Condition": [Condition: Concepts."CI-Severe allergic reactions"]
/* @internal: Condition for Severe allergic reactions */ define "CI Severe allergic reactions Condition": Elements."CI Severe allergic reactions Condition" C where C.prevalenceInterval() includes Today
The client has history of severe allergic reactions
/* @input: The client has history of severe allergic reactions @pseudocode: "Potential contraindications" = "Severe allergic reactions" */ define "The client has history of severe allergic reactions": exists "CI Severe allergic reactions Observation" or exists "CI Severe allergic reactions Condition"
The client has a history of severe allergic reactions
/* @input: The client has a history of severe allergic reactions @pseudocode: "Potential contraindications" = "Severe allergic reactions" @code: The client has a history of severe allergic reactions-59 @decision: IMMZ.D5.DT.Yellow fever contraindications */ define "The client has a history of severe allergic reactions": Encounter."The client has history of severe allergic reactions"
Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note
/* @output: Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note @pseudocode: "Immunization recommendation status" = "Further evaluation needed" */ define "Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note": Encounter."The client has a history of severe allergic reactions"
Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note Guidance
/* @output: Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note Guidance @guidance: Do not vaccinate client with yellow fever if client has severe hypersensitivity to egg antigens. */ define "Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note Guidance": 'Do not vaccinate client with yellow fever if client has severe hypersensitivity to egg antigens.'
/* @dynamicValue: Guidance */ define "Guidance": case when "Yellow fever vaccination is contraindicated" then "Yellow fever vaccination is contraindicated Guidance" when "Clinical judgement is required. Create a clinical note" then "Clinical judgement is required. Create a clinical note Guidance" when "Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note" then "Yellow fever vaccination could be contraindicated. Clinical judgement is required. Create a clinical note Guidance" else '' end
/* @dataElement: Draft Medication Request for Patient */ define "Draft Medication Request for Patient": [MedicationRequest] MR where MR.status = 'draft' and MR.intent = 'proposal' sort by date from (authoredOn as FHIR.dateTime) desc
/* @dataElement: Draft Medication Request for Patient */ define "Draft Medication Request for Patient": Elements."Draft Medication Request for Patient" MR where MR.encounter.references(EncounterId) or MR.authoredOn.toInterval() same day or before Today sort by date from (authoredOn as FHIR.dateTime) desc
Draft Medication Request for Yellow fever dose
/* @internal: Draft Medication Request for Yellow fever dose */ define "Draft Medication Request for Yellow fever dose": Encounter."Draft Medication Request for Patient" MR where MR.medication in Concepts."Yellow fever vaccines"
Draft Medication Request ID for Yellow fever dose
/* @dynamicValue: Draft Medication Request ID for Yellow fever dose */ define "Draft Medication Request ID for Yellow fever dose": First(Encounter."Draft Medication Request for Yellow fever dose").id
define "Has Guidance": "Guidance" is not null and "Guidance" != ''
/** * @description: Gets observation from an encounter or on or before a date */ define fluent function encounterOrOnBefore(observations List<Observation>, EncounterId String, beforeDate Date): observations O where (O.encounter.references(EncounterId) or O.effective.toInterval() starts same day or before beforeDate)
/* @description: Returns true if the given reference is to the given resourceId @comment: Returns true if the `resourceId` parameter exactly equals the tail of the given reference. NOTE: This function assumes resources from the same source server. */ define fluent function references(reference FHIR.Reference, resourceId String): resourceId = Last(Split(reference.reference, '/'))
define function ToString(value string): value.value
define fluent function complete(observations List<Observation>): observations O where O.status in { 'final', 'amended', 'corrected' }
define function ToString(value ObservationStatus): value.value
define function ToConcept(concept FHIR.CodeableConcept): if concept is null then null else System.Concept { codes: concept.coding C return ToCode(C), display: concept.text.value }
define function ToCode(coding FHIR.Coding): if coding is null then null else System.Code { code: coding.code.value, system: coding.system.value, version: coding.version.value, display: coding.display.value }
/* @description: Returns an interval representing the normalized prevalence period of a given Condition resource. @comment: Uses the toInterval and toAbatementInterval functions to determine the widest potential interval from onset to abatement as specified in the given Condition. */ define fluent function prevalenceInterval(condition Condition): if condition.clinicalStatus ~ "active" or condition.clinicalStatus ~ "recurrence" or condition.clinicalStatus ~ "relapse" then Interval[start of condition.onset.toInterval(), end of condition.abatementInterval()] else (end of condition.abatementInterval()) abatementDate return if abatementDate is null then Interval[start of condition.onset.toInterval(), abatementDate) else Interval[start of condition.onset.toInterval(), abatementDate]
// Was getting error on this for this particular choice set not being found /* @description: Returns an interval representing the normalized Abatement of a given Condition resource. @comment: NOTE: Due to the complexity of determining an interval from a String, this function will throw a run-time exception if used with a Condition instance that has a String as the abatement value. */ define fluent function abatementInterval(condition Condition): if condition.abatement is FHIR.dateTime then Interval[FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime), FHIRHelpers.ToDateTime(condition.abatement as FHIR.dateTime)] else if condition.abatement is FHIR.Period then FHIRHelpers.ToInterval(condition.abatement as FHIR.Period) else if condition.abatement is FHIR.string then Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported') else if condition.abatement is FHIR.Age then Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age), FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(condition.abatement as FHIR.Age) + 1 year) else if condition.abatement is FHIR.Range then Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).low), FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((condition.abatement as FHIR.Range).high) + 1 year) else if condition.abatement is FHIR.boolean then Interval[end of condition.onset.toInterval(), condition.recordedDate) else null
define function ToDateTime(value dateTime): value.value
define function ToInterval(period FHIR.Period): if period is null then null else if period."start" is null then Interval(period."start".value, period."end".value] else Interval[period."start".value, period."end".value]
define function ToDate(value date): value.value
define function ToQuantity(quantity FHIR.Quantity): case when quantity is null then null when quantity.value is null then null when quantity.comparator is not null then Message(null, true, 'FHIRHelpers.ToQuantity.ComparatorQuantityNotSupported', 'Error', 'FHIR Quantity value has a comparator and cannot be converted to a System.Quantity value.') when quantity.system is null or quantity.system.value = 'http://unitsofmeasure.org' or quantity.system.value = 'http://hl7.org/fhirpath/CodeSystem/calendar-units' then System.Quantity { value: quantity.value.value, unit: ToCalendarUnit(Coalesce(quantity.code.value, quantity.unit.value, '1')) } else Message(null, true, 'FHIRHelpers.ToQuantity.InvalidFHIRQuantity', 'Error', 'Invalid FHIR Quantity code: ' & quantity.unit.value & ' (' & quantity.system.value & '|' & quantity.code.value & ')') end
define function ToCalendarUnit(unit System.String): case unit when 'ms' then 'millisecond' when 's' then 'second' when 'min' then 'minute' when 'h' then 'hour' when 'd' then 'day' when 'wk' then 'week' when 'mo' then 'month' when 'a' then 'year' else unit end
define function ToString(value MedicationRequestStatus): value.value
define function ToString(value MedicationRequestIntent): value.value
/* From FHIRCommon 4.1.0: */ /* @description: Normalizes a value that is a choice of timing-valued types to an equivalent interval @comment: Normalizes a choice type of FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instance, FHIR.string, FHIR.Age, or FHIR.Range types to an equivalent interval. This selection of choice types is a superset of the majority of choice types that are used as possible representations for timing-valued elements in FHIR, allowing this function to be used across any resource. The input can be provided as a dateTime, Period, Timing, instant, string, Age, or Range. The intent of this function is to provide a clear and concise mechanism to treat single elements that have multiple possible representations as intervals so that logic doesn't have to account for the variability. More complex calculations (such as medication request period or dispense period calculation) need specific guidance and consideration. That guidance may make use of this function, but the focus of this function is on single element calculations where the semantics are unambiguous. If the input is a dateTime, the result a DateTime Interval beginning and ending on that dateTime. If the input is a Period, the result is a DateTime Interval. If the input is a Timing, an error is raised indicating a single interval cannot be computed from a Timing. If the input is an instant, the result is a DateTime Interval beginning and ending on that instant. If the input is a string, an error is raised indicating a single interval cannot be computed from a string. If the input is an Age, the result is a DateTime Interval beginning when the patient was the given Age, and ending immediately prior to when the patient was the given Age plus one year. If the input is a Range, the result is a DateTime Interval beginning when the patient was the Age given by the low end of the Range, and ending immediately prior to when the patient was the Age given by the high end of the Range plus one year. NOTE: Due to the complexity of determining a single interval from a Timing or String type, this function will throw a run-time exception if it is used with a Timing or String. */ define fluent function toInterval(choice Choice<FHIR.dateTime, FHIR.Period, FHIR.Timing, FHIR.instant, FHIR.string, FHIR.Age, FHIR.Range>): case when choice is FHIR.dateTime then Interval[FHIRHelpers.ToDateTime(choice as FHIR.dateTime), FHIRHelpers.ToDateTime(choice as FHIR.dateTime)] when choice is FHIR.Period then FHIRHelpers.ToInterval(choice as FHIR.Period) when choice is FHIR.instant then Interval[FHIRHelpers.ToDateTime(choice as FHIR.instant), FHIRHelpers.ToDateTime(choice as FHIR.instant)] when choice is FHIR.Age then Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age), FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity(choice as FHIR.Age) + 1 year) when choice is FHIR.Range then Interval[FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).low), FHIRHelpers.ToDate(Patient.birthDate) + FHIRHelpers.ToQuantity((choice as FHIR.Range).high) + 1 year) when choice is FHIR.Timing then Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a Timing value is not supported') when choice is FHIR.string then Message(null as Interval<DateTime>, true, 'NOT_IMPLEMENTED', 'Error', 'Calculation of an interval from a String value is not supported') else null as Interval<DateTime> end
define function ToDateTime(value instant): value.value
Code system ConditionClinicalStatusCodes
IMMZ.D5.DT.Yellow fever contraindications
IMMZ.D5.DT.Yellow fever contraindications IMMZ.D5.DT.Yellow fever contraindications
WHO recommendations for routine immunization - summary tables (January 2025)
Check for contraindications before administering the vaccine(s) due
Contraindication for Yellow fever immunization
Concept { codes: { Code { system: 'http://smart.who.int/immunizations/CodeSystem/IMMZ.Z', code: 'DE23', display: 'Yellow fever vaccines' } }, display: 'Yellow fever vaccines' }
Check for Guidance for the patient regarding IMMZ.D5.DT.Yellow fever contraindications.
Show Guidance for the patient regarding IMMZ.D5.DT.Yellow fever contraindications.
Code { system: 'http://terminology.hl7.org/CodeSystem/communication-category', code: 'alert' }
Code { system: 'http://hl7.org/fhir/request-priority', code: 'routine' }