Id: IMMZD18SVaricella2Doses Url: IMMZ.D18.S.Varicella.2-dose schedule Version: 0.2.0 Title: IMMZ.D18.S.Varicella.2-dose schedule 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.D18.S.Varicella.2-dose schedule 2-dose schedule Knowledge Capability: computable Related Artifacts: References WHO recommendations for routine immunization - summary tables (January 2025) Libraries: IMMZD18SVaricella2DosesLogic Actions: Varicella dose 1: Provision of the varicella dose 1 Trigger event: Child's birth Trigger pseudo: Trigger date: "Date of birth" Create condition: Depending on the goal of the vaccination programme, 1–2 doses should be given with the first dose administered at 12–18 months of age. If: Applicability: Varicella dose 1 (Varicella dose 1) Then: Definition: IMMZ.D2.DT.CR Dynamic Values: status: ('active') payload.contentString: (Varicella dose 1 Create) category.coding: (Code { system: 'http://terminology.hl7.org/CodeSystem/communication-category', code: 'alert' }) priority: (Code { system: 'http://hl7.org/fhir/request-priority', code: 'routine' }) Varicella dose 2: Provision of the varicella dose 2 Trigger event: First varicella dose from the primary series was administered Trigger pseudo: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") =1 Trigger date: "Date and time of vaccination" (where "Vaccine type" = "Varicella-containing vaccines") Create condition: The minimum interval between doses should be as recommended by the manufacturer, ranging from 4 weeks to 3 months. If: Applicability: Varicella dose 2 (Varicella dose 2) Then: Definition: IMMZ.D2.DT.CR Dynamic Values: status: ('active') payload.contentString: (Varicella dose 2 Create) 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 All Doses Administered to Patient */ define "Doses Administered to Patient": [Immunization] I where I.status = 'completed' and I.isSubpotent is not true
/** * @dataElement All Doses Administered to Patient */ define "Doses Administered to Patient": Elements."Doses Administered to Patient" I where I.occurrence.toInterval() same day or before Today
/* @internal: Varicella containing Doses Administered to Patient */ define "Varicella Doses Administered to Patient": Encounter."Doses Administered to Patient" I where I.vaccineCode in Concepts."Varicella-containing vaccines"
Varicella Primary Series Doses Administered to Patient
/* @internal: Varicella containing Doses Administered to Patient that are in the Primary series */ define "Varicella Primary Series Doses Administered to Patient": "Varicella Doses Administered to Patient".seriesPrimary()
Number of Varicella Primary Series Doses Administered
/* @internal: Number of Varicella Primary Series doses */ define "Number of Varicella Primary Series Doses Administered": Count("Varicella Primary Series Doses Administered to Patient")
One varicella primary series dose was administered
/* @input: One varicella primary series dose was administered @pseudocode: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") = 1 @code: One varicella primary series dose was administered-129 @decision: IMMZ.D2.DT.Varicella.1 dose: Countries where varicella is an important public health burden could consider introducing varicella vaccination in the routine childhood immunization programme. However, resources should be sufficient to ensure reaching and sustaining vaccine coverage ≥ 80%. Decision-making on childhood varicella vaccination should also include consideration of the possible impact on herpes zoster. The number of doses recommended is dependent on the goal of the vaccination programme. One dose is sufficient to reduce mortality and severe morbidity from varicella but not to prevent limited virus circulation and outbreaks. Two doses have higher effectiveness and should therefore be recommended in countries where the programmatic goal is, in addition to decreasing mortality and severe morbidity, to further reduce the number of cases and outbreaks. @decision: IMMZ.D2.DT.Varicella.2 doses: Countries where varicella is an important public health burden could consider introducing varicella vaccination in the routine childhood immunization programme. However, resources should be sufficient to ensure reaching and sustaining vaccine coverage ≥ 80%. Decision-making on childhood varicella vaccination should also include consideration of the possible impact on herpes zoster. The number of doses recommended is dependent on the goal of the vaccination programme. One dose is sufficient to reduce mortality and severe morbidity from varicella but not to prevent limited virus circulation and outbreaks. Two doses have higher effectiveness and should therefore be recommended in countries where the programmatic goal is, in addition to decreasing mortality and severe morbidity, to further reduce the number of cases and outbreaks. */ define "One varicella primary series dose was administered": "Number of Varicella Primary Series Doses Administered" = 1
First varicella dose from the primary series was administered
/* @complete: First varicella dose from the primary series was administered @pseudocode: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") =1 */ define "First varicella dose from the primary series was administered": Encounter."One varicella primary series dose was administered"
Two varicella primary series doses were administered
/* @input: Two varicella primary series doses were administered @pseudocode: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") = 2 @code: Two varicella primary series doses were administered-129 @decision: IMMZ.D2.DT.Varicella.2 doses: Countries where varicella is an important public health burden could consider introducing varicella vaccination in the routine childhood immunization programme. However, resources should be sufficient to ensure reaching and sustaining vaccine coverage ≥ 80%. Decision-making on childhood varicella vaccination should also include consideration of the possible impact on herpes zoster. The number of doses recommended is dependent on the goal of the vaccination programme. One dose is sufficient to reduce mortality and severe morbidity from varicella but not to prevent limited virus circulation and outbreaks. Two doses have higher effectiveness and should therefore be recommended in countries where the programmatic goal is, in addition to decreasing mortality and severe morbidity, to further reduce the number of cases and outbreaks. */ define "Two varicella primary series doses were administered": "Number of Varicella Primary Series Doses Administered" = 2
Second varicella dose from the primary series was administered. The primary series has been completed
/* @complete: Second varicella dose from the primary series was administered. The primary series has been completed @pseudocode: "Completed the primary vaccination series" = TRUE (where "Vaccine type" = "Varicella-containing vaccines")" */ define "Second varicella dose from the primary series was administered. The primary series has been completed": Encounter."Two varicella primary series doses were administered"
/* @output: Varicella dose 2 @description: Provision of the varicella dose 2 @trigger: First varicella dose from the primary series was administered @pseudo: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") =1 @triggerDate: "Date and time of vaccination" (where "Vaccine type" = "Varicella-containing vaccines") */ define "Varicella dose 2": "First varicella dose from the primary series was administered" and not "Second varicella dose from the primary series was administered. The primary series has been completed"
/* @internal: Date of Latest Varicella Dose */ define "Date of Latest Varicella Dose": date from start of "Varicella Doses Administered to Patient".mostRecent().occurrence.toInterval()
/* @dynamicValue: Varicella dose 2 Due Date @pseudocode: "Date and time of vaccination" (where "Vaccine type" = "Varicella-containing vaccines") + 4 weeks */ define "Varicella dose 2 Due Date": if "Varicella dose 2" then Encounter."Date of Latest Varicella Dose" + 4 weeks else null
/* @output: Varicella dose 2 Create @create: The minimum interval between doses should be as recommended by the manufacturer, ranging from 4 weeks to 3 months. */ define "Varicella dose 2 Create": if "Varicella dose 2" then 'The minimum interval between doses should be as recommended by the manufacturer, ranging from 4 weeks to 3 months.' + ' Due Date: ' + ToString("Varicella dose 2 Due Date") else ''
No varicella primary series dose was administered
/* @input: No varicella primary series dose was administered @pseudocode: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") = 0 @code: No varicella primary series dose was administered-129 @decision: IMMZ.D2.DT.Varicella.1 dose: Countries where varicella is an important public health burden could consider introducing varicella vaccination in the routine childhood immunization programme. However, resources should be sufficient to ensure reaching and sustaining vaccine coverage ≥ 80%. Decision-making on childhood varicella vaccination should also include consideration of the possible impact on herpes zoster. The number of doses recommended is dependent on the goal of the vaccination programme. One dose is sufficient to reduce mortality and severe morbidity from varicella but not to prevent limited virus circulation and outbreaks. Two doses have higher effectiveness and should therefore be recommended in countries where the programmatic goal is, in addition to decreasing mortality and severe morbidity, to further reduce the number of cases and outbreaks. */ define "No varicella primary series dose was administered": "Number of Varicella Primary Series Doses Administered" = 0
No varicella primary series doses were administered
/* @input: No varicella primary series doses were administered @pseudocode: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") = 0 @code: No varicella primary series doses were administered-129 @decision: IMMZ.D2.DT.Varicella.2 doses: Countries where varicella is an important public health burden could consider introducing varicella vaccination in the routine childhood immunization programme. However, resources should be sufficient to ensure reaching and sustaining vaccine coverage ≥ 80%. Decision-making on childhood varicella vaccination should also include consideration of the possible impact on herpes zoster. The number of doses recommended is dependent on the goal of the vaccination programme. One dose is sufficient to reduce mortality and severe morbidity from varicella but not to prevent limited virus circulation and outbreaks. Two doses have higher effectiveness and should therefore be recommended in countries where the programmatic goal is, in addition to decreasing mortality and severe morbidity, to further reduce the number of cases and outbreaks. */ define "No varicella primary series doses were administered": "No varicella primary series dose was administered"
/* @output: Varicella dose 1 @description: Provision of the varicella dose 1 @trigger: Child's birth @pseudo: @triggerDate: "Date of birth" */ define "Varicella dose 1": Encounter."No varicella primary series doses were administered" and not "First varicella dose from the primary series was administered"
/* @dynamicValue: Varicella dose 1 Due Date @pseudocode: "Date of birth" + 12 months */ define "Varicella dose 1 Due Date": if "Varicella dose 1" then Patient.birthDate + 12 months else null
/* @dynamicValue: Varicella dose 1 Overdue @pseudocode: "Date of birth" + 18 months */ define "Varicella dose 1 Overdue": if "Varicella dose 1" then Patient.birthDate + 18 months else null
/* @output: Varicella dose 1 Create @create: Depending on the goal of the vaccination programme, 1–2 doses should be given with the first dose administered at 12–18 months of age. */ define "Varicella dose 1 Create": if "Varicella dose 1" then 'Depending on the goal of the vaccination programme, 1–2 doses should be given with the first dose administered at 12–18 months of age.' + ' Due Date: ' + ToString("Varicella dose 1 Due Date") + ' Overdue: ' + ToString("Varicella dose 1 Overdue") else ''
/** * @description: Gets the doses from the primary series */ define fluent function seriesPrimary(immunizations List<Immunization>): immunizations I where exists( I.protocolApplied pa where pa.series = 'Primary series' )
define function ToString(value string): value.value
define function ToString(value ImmunizationStatus): value.value
define function ToBoolean(value boolean): 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 }
define fluent function mostRecent(immunizations List<Immunization>): Last( immunizations I sort by start of occurrence.toInterval() )
define function ToDate(value date): value.value
IMMZ.D18.S.Varicella.2-dose schedule 2-dose schedule
WHO recommendations for routine immunization - summary tables (January 2025)
Provision of the varicella dose 1 Trigger event: Child's birth Trigger pseudo: Trigger date: "Date of birth" Create condition: Depending on the goal of the vaccination programme, 1–2 doses should be given with the first dose administered at 12–18 months of age.
Code { system: 'http://terminology.hl7.org/CodeSystem/communication-category', code: 'alert' }
Code { system: 'http://hl7.org/fhir/request-priority', code: 'routine' }
Provision of the varicella dose 2 Trigger event: First varicella dose from the primary series was administered Trigger pseudo: Count of vaccines administered (where "Vaccine type" = "Varicella-containing vaccines" and "Type of dose" = "Primary series") =1 Trigger date: "Date and time of vaccination" (where "Vaccine type" = "Varicella-containing vaccines") Create condition: The minimum interval between doses should be as recommended by the manufacturer, ranging from 4 weeks to 3 months.