Immunizations Service — Migration Plan

Status: populated Owner: TBD Last updated: 2026-04-18 Companion: Service Template

1. Migration Scenarios

Scenario A: Greenfield Deployment

1. Run DB migrations (pnpm db:migrate).
2. Load Afghanistan EPI schedule into config/epi-schedule.json.
3. Verify EPI schedule loads and forecasts calculate correctly for sample patients.
4. Configure national registry sync credentials.
5. Begin recording immunizations.

Scenario B: Migration from Paper Registers / Legacy HMIS

Step	Action
1	Extract historical immunization records from paper register digitization or legacy HMIS export (patient ID, vaccine, dose number, date)
2	Map vaccine names to CVX codes using terminology-service lookup table
3	Register patients in registration-service first (REG-US-001)
4	Import historical records via POST /v1/immunizations/historical with source.type: "paper_card" or "external_emr"
5	Trigger forecast refresh for all imported patients: POST /v1/immunizations/forecast/:patientId/refresh
6	Validate forecast outputs against expected schedule position for a sample of patients
7	Generate defaulter list and review with district vaccination officer

Scenario C: HL7 VXU / National Registry Cutover

1. Configure interop-service with national registry VXU adapter pointing to immunizations-service.
2. Run parallel mode (2 weeks): compare VXU-imported records with paper register records.
3. Validate no duplicate or conflicting records.
4. Cut over live registry sync (enable SyncToRegistryUseCase cron).

2. Rollback Plan

• Schema: Drizzle down migrations per step.
• Data: Historical imports use source_type field; truncate by source type and date range on rollback.
• Registry sync: Disable registry sync cron in environment config; no registry records are mutated by rollback.

3. Phased Delivery

Phase	Scope	Slice
Phase 1	Core record + refusal + basic forecast	S0
Phase 2	Defaulter tracking + outreach event	S1
Phase 3	National registry bidirectional sync	S2
Phase 4	Digital certificates + coverage analytics	S2
Phase 5	AI-assisted defaulter prioritisation	S3