diff --git a/app/lib/mavis_cli.rb b/app/lib/mavis_cli.rb
index 3fde173c8b..ea014c9b73 100644
--- a/app/lib/mavis_cli.rb
+++ b/app/lib/mavis_cli.rb
@@ -29,15 +29,16 @@ def self.progress_bar(total)
 require_relative "mavis_cli/gias/download"
 require_relative "mavis_cli/gias/import"
 require_relative "mavis_cli/gp_practices/import"
-require_relative "mavis_cli/nhs_api/access_token"
-require_relative "mavis_cli/pds/get"
-require_relative "mavis_cli/pds/search"
 require_relative "mavis_cli/local_authorities/download"
 require_relative "mavis_cli/local_authorities/download_gias_codes"
+require_relative "mavis_cli/local_authorities/download_postcode_mappings"
 require_relative "mavis_cli/local_authorities/import"
 require_relative "mavis_cli/local_authorities/import_gias_codes"
-require_relative "mavis_cli/local_authorities/download_postcode_mappings"
 require_relative "mavis_cli/local_authorities/import_postcode_mappings"
+require_relative "mavis_cli/nhs_api/access_token"
+require_relative "mavis_cli/pds/get"
+require_relative "mavis_cli/pds/search"
+require_relative "mavis_cli/reporting_api/update_vaccination_events"
 require_relative "mavis_cli/schools/add_programme_year_group"
 require_relative "mavis_cli/schools/add_to_team"
 require_relative "mavis_cli/schools/create"
@@ -53,7 +54,7 @@ def self.progress_bar(total)
 require_relative "mavis_cli/teams/list"
 require_relative "mavis_cli/teams/onboard"
 require_relative "mavis_cli/users/create"
-require_relative "mavis_cli/vaccination_records/generate_fhir"
-require_relative "mavis_cli/vaccination_records/sync"
 require_relative "mavis_cli/vaccination_records/create_from_fhir"
+require_relative "mavis_cli/vaccination_records/generate_fhir"
 require_relative "mavis_cli/vaccination_records/search_imms_api"
+require_relative "mavis_cli/vaccination_records/sync"
diff --git a/app/lib/mavis_cli/reporting_api/update_vaccination_events.rb b/app/lib/mavis_cli/reporting_api/update_vaccination_events.rb
new file mode 100644
index 0000000000..9bf7b0ecb2
--- /dev/null
+++ b/app/lib/mavis_cli/reporting_api/update_vaccination_events.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+module MavisCLI
+  module ReportingAPI
+    class UpdateVaccinationEvents < Dry::CLI::Command
+      desc <<-DESC
+      Update ReportingAPI Vaccination Events for all VaccinationRecords created after a given DateTime.
+      DateTimes can be given in any format parsable by Time.parse.
+      Defaults to one year ago.
+      DESC
+
+      option :from,
+             desc: "Only consider vaccination records created after this time",
+             type: :string,
+             optional: true,
+             aliases: %w[--from],
+             default: nil
+
+      def call(from: nil, **)
+        MavisCLI.load_rails
+
+        min_datetime = from ? Time.zone.parse(from) : (Time.zone.now - 1.year)
+
+        vaccination_records =
+          VaccinationRecord.where("created_at > ?", min_datetime)
+        puts "#{vaccination_records.count} VaccinationRecords created since #{min_datetime.iso8601}"
+        if vaccination_records.exists?
+          puts "Updating VaccinationEvents"
+          progress_bar = MavisCLI.progress_bar(vaccination_records.count + 1)
+
+          vaccination_records.find_each do |vaccination_record|
+            vaccination_record.create_or_update_reporting_api_vaccination_event!
+            progress_bar.increment
+          end
+        else
+          puts "Nothing to do"
+        end
+      end
+    end
+  end
+
+  register "reporting-api" do |prefix|
+    prefix.register "update-vaccination-events",
+                    ReportingAPI::UpdateVaccinationEvents
+  end
+end
diff --git a/app/models/vaccination_record.rb b/app/models/vaccination_record.rb
index 46b8074f57..35517aaa54 100644
--- a/app/models/vaccination_record.rb
+++ b/app/models/vaccination_record.rb
@@ -230,6 +230,34 @@ def snomed_procedure_code = vaccine&.snomed_procedure_code(dose_sequence:)
 
   delegate :snomed_procedure_term, to: :vaccine, allow_nil: true
 
+  def create_or_update_reporting_api_vaccination_event!
+    re =
+      ReportingAPI::VaccinationEvent.find_or_initialize_by(
+        source_id: id,
+        source_type: self.class.name
+      )
+    re.event_timestamp = performed_at
+    re.event_type = outcome
+
+    re.copy_attributes_from_references(
+      patient: patient.reload,
+      patient_local_authority_from_postcode:
+        patient.local_authority_from_postcode,
+      patient_school: patient.school,
+      patient_school_local_authority: patient.school&.local_authority,
+      location:,
+      location_local_authority: location&.local_authority,
+      vaccination_record: self,
+      vaccine:,
+      team:,
+      organisation: team.organisation,
+      programme:
+    )
+
+    re.save!
+    re
+  end
+
   private
 
   def requires_location_name? = location.nil?
diff --git a/spec/features/cli_reporting_api_update_vaccination_events_spec.rb b/spec/features/cli_reporting_api_update_vaccination_events_spec.rb
new file mode 100644
index 0000000000..f38a8dac35
--- /dev/null
+++ b/spec/features/cli_reporting_api_update_vaccination_events_spec.rb
@@ -0,0 +1,151 @@
+# frozen_string_literal: true
+
+require_relative "../../app/lib/mavis_cli"
+
+describe "mavis reporting-api update-vaccination-events" do
+  it "generates Reporting API Vaccination Event records" do
+    given_a_team_exists
+    and_there_is_a_patient_in_a_session
+    and_there_are_some_vaccination_records
+    when_i_run_the_reporting_api_update_vaccination_events_command
+    then_reporting_api_vaccination_events_are_created
+  end
+
+  it "updates existing Reporting API Vaccination Event records" do
+    given_a_team_exists
+    and_there_is_a_patient_in_a_session
+    and_there_are_some_vaccination_records
+    and_the_vaccination_records_already_have_reporting_api_vaccination_events
+    when_i_run_the_reporting_api_update_vaccination_events_command
+    then_it_does_not_generate_new_vaccination_event_records
+    and_it_updates_the_existing_vaccination_event_records
+  end
+
+  it "only affects Vaccination Records created after the given from_datetime" do
+    given_a_team_exists
+    and_there_is_a_patient_in_a_session
+    and_there_are_some_vaccination_records
+    when_i_run_the_reporting_api_update_vaccination_events_command_with_a_from_datetime
+    then_event_records_are_only_created_for_vaccination_records_created_after_the_given_from_datetime
+  end
+
+  def given_a_team_exists
+    @programme =
+      Programme.find_by(type: "hpv") || create(:programme, type: "hpv")
+    @team = create(:team, programmes: [@programme])
+  end
+
+  def nurse
+    User.find_by(fallback_role: :nurse) || create(:nurse)
+  end
+
+  def and_there_is_a_patient_in_a_session
+    subteam = create(:subteam, team: @team)
+    location = create(:generic_clinic, subteam:)
+    @session =
+      create(:session, team: @team, programmes: [@programme], location:)
+    parent = create(:parent)
+    @patient =
+      create(
+        :patient,
+        :consent_given_triage_not_needed,
+        team: @team,
+        session: @session,
+        programmes: [@programme],
+        parents: [parent]
+      )
+    @other_patient =
+      create(
+        :patient,
+        :consent_given_triage_not_needed,
+        team: @team,
+        session: @session,
+        programmes: [@programme],
+        parents: [parent]
+      )
+  end
+
+  def and_there_are_some_vaccination_records
+    @vr1 =
+      create(
+        :vaccination_record,
+        patient: @patient,
+        session: @session,
+        location: @session.location,
+        performed_by: nurse,
+        programme: @programme,
+        created_at: Time.current - 1.day,
+        updated_at: Time.current - 1.day
+      )
+    @vr2 =
+      create(
+        :vaccination_record,
+        patient: @other_patient,
+        session: @session,
+        location: @session.location,
+        performed_by: nurse,
+        programme: @programme,
+        created_at: Time.current - 4.hours,
+        updated_at: Time.current - 4.hours
+      )
+  end
+
+  def and_the_vaccination_records_already_have_reporting_api_vaccination_events
+    VaccinationRecord.all.find_each(
+      &:create_or_update_reporting_api_vaccination_event!
+    )
+  end
+
+  def when_i_run_the_reporting_api_update_vaccination_events_command
+    @vaccination_events_count_before = ReportingAPI::VaccinationEvent.count
+
+    MavisCLI.instance_variable_set(:@progress_bar, nil)
+
+    @output =
+      capture_output do
+        Dry::CLI.new(MavisCLI).call(
+          arguments: %w[reporting-api update-vaccination-events]
+        )
+      end
+  end
+
+  def when_i_run_the_reporting_api_update_vaccination_events_command_with_a_from_datetime
+    @vaccination_events_count_before = ReportingAPI::VaccinationEvent.count
+
+    MavisCLI.instance_variable_set(:@progress_bar, nil)
+
+    @output =
+      capture_output do
+        Dry::CLI.new(MavisCLI).call(
+          arguments: [
+            "reporting-api",
+            "update-vaccination-events",
+            "--from",
+            (Time.current - 8.hours).iso8601.to_s
+          ]
+        )
+      end
+  end
+
+  def then_reporting_api_vaccination_events_are_created
+    expect(ReportingAPI::VaccinationEvent.count).to be >
+      @vaccination_events_count_before
+  end
+
+  def then_event_records_are_only_created_for_vaccination_records_created_after_the_given_from_datetime
+    expect(ReportingAPI::VaccinationEvent.count).to eq(1)
+    expect(ReportingAPI::VaccinationEvent.last.source_id).to eq(@vr2.id)
+  end
+
+  def then_it_does_not_generate_new_vaccination_event_records
+    expect(
+      ReportingAPI::VaccinationEvent.count
+    ).to eq @vaccination_events_count_before
+  end
+
+  def and_it_updates_the_existing_vaccination_event_records
+    expect(ReportingAPI::VaccinationEvent.pluck(:updated_at)).to all be_within(
+          1.second
+        ).of(Time.current)
+  end
+end
diff --git a/spec/models/vaccination_record_spec.rb b/spec/models/vaccination_record_spec.rb
index d700bdc15e..6e690940e8 100644
--- a/spec/models/vaccination_record_spec.rb
+++ b/spec/models/vaccination_record_spec.rb
@@ -460,4 +460,189 @@
       end
     end
   end
+
+  describe "#create_or_update_reporting_api_vaccination_event" do
+    subject(:vaccination_record) do
+      create(
+        :vaccination_record,
+        programme: flu,
+        outcome: :not_well,
+        session: session,
+        location: school,
+        patient: patient
+      )
+    end
+
+    let(:flu) do
+      Programme.find_by_type("flu") || create(:programme, type: "flu")
+    end
+    let(:programmes) { [flu] }
+    let(:team) { create(:team, programmes:) }
+    let(:session) { create(:session, team:, programmes:) }
+    let(:school) { create(:school, gias_local_authority_code: 999_999) }
+    let(:patient) do
+      create(:patient, address_postcode: "DH1 3LH", school: school)
+    end
+    let(:local_authority) do
+      create(:local_authority, gss_code: "D000000001", gias_code: 999_999)
+    end
+
+    before do
+      create(
+        :local_authority_postcode,
+        gss_code: local_authority.gss_code,
+        value: "DH1 3LH"
+      )
+    end
+
+    context "when a reporting_api_vaccination_event already exists with this vaccination_record as source" do
+      let!(:existing_event) do
+        create(
+          :reporting_api_vaccination_event,
+          source: vaccination_record,
+          outcome: "not_well"
+        )
+      end
+
+      before { vaccination_record.update!(outcome: :administered) }
+
+      it "does not create a new reporting_api_vaccination_event" do
+        expect {
+          vaccination_record.create_or_update_reporting_api_vaccination_event!
+        }.not_to change(ReportingAPI::VaccinationEvent, :count)
+      end
+
+      it "updates the existing reporting_api_vaccination_event" do
+        vaccination_record.create_or_update_reporting_api_vaccination_event!
+
+        expect(existing_event.reload.vaccination_record_outcome).to eq(
+          "administered"
+        )
+      end
+    end
+
+    context "when no reporting_api_vaccination_event exists with this vaccination_record as source" do
+      it "creates a new reporting_api_vaccination_event" do
+        expect {
+          vaccination_record.create_or_update_reporting_api_vaccination_event!
+        }.to change(ReportingAPI::VaccinationEvent, :count).by(1)
+      end
+
+      describe "the created VaccinationEvent" do
+        before do
+          vaccination_record.create_or_update_reporting_api_vaccination_event!
+        end
+
+        let(:event) do
+          ReportingAPI::VaccinationEvent.find_by(
+            source_id: vaccination_record.id
+          )
+        end
+
+        it "has this vaccination_record as source" do
+          expect(event.source).to eq(vaccination_record)
+        end
+
+        it "has the outcome as event_type" do
+          expect(event.event_type).to eq(vaccination_record.outcome)
+        end
+
+        it "has performed_at as event_timestamp" do
+          expect(event.event_timestamp).to eq(vaccination_record.performed_at)
+        end
+
+        describe "denormalized relation properties" do
+          it "has patient_ attributes set" do
+            expect(event).to have_attributes(
+              patient_id: patient.id,
+              patient_address_town: patient.address_town,
+              patient_address_postcode: patient.address_postcode,
+              patient_gender_code: patient.gender_code,
+              patient_home_educated: patient.home_educated,
+              patient_date_of_death: patient.date_of_death,
+              patient_birth_academic_year: patient.birth_academic_year
+            )
+          end
+
+          it "has patient_school_ attributes set" do
+            expect(event).to have_attributes(
+              patient_school_id: school.id,
+              patient_school_address_town: school.address_town,
+              patient_school_address_postcode: school.address_postcode,
+              patient_school_name: school.name,
+              patient_school_gias_local_authority_code:
+                school.gias_local_authority_code,
+              patient_school_type: school.type
+            )
+          end
+
+          it "has patient_school_local_authority_ attributes set" do
+            expect(event).to have_attributes(
+              patient_school_local_authority_short_name:
+                local_authority.short_name,
+              patient_school_local_authority_mhclg_code:
+                local_authority.mhclg_code
+            )
+          end
+
+          it "has patient_local_authority_from_postcode_ attributes set" do
+            expect(event).to have_attributes(
+              patient_local_authority_from_postcode_short_name:
+                patient.local_authority_from_postcode.short_name,
+              patient_local_authority_from_postcode_mhclg_code:
+                patient.local_authority_from_postcode.mhclg_code
+            )
+          end
+
+          it "has location_ attributes set" do
+            expect(event).to have_attributes(
+              location_id: school.id,
+              location_address_town: school.address_town,
+              location_address_postcode: school.address_postcode,
+              location_name: school.name,
+              location_type: school.type
+            )
+          end
+
+          it "has location_local_authority_ attributes set" do
+            expect(event).to have_attributes(
+              location_local_authority_short_name: local_authority.short_name,
+              location_local_authority_mhclg_code: local_authority.mhclg_code
+            )
+          end
+
+          it "has team_ attributes set" do
+            expect(event).to have_attributes(
+              team_id: team&.id,
+              team_name: team&.name
+            )
+          end
+
+          it "has organisation_ attributes set" do
+            expect(event).to have_attributes(
+              organisation_id: team.organisation.id,
+              organisation_ods_code: team.organisation.ods_code
+            )
+          end
+
+          it "has programme_ attributes set" do
+            expect(event).to have_attributes(
+              programme_id: flu.id,
+              programme_type: flu.type
+            )
+          end
+
+          it "has vaccination_record_ attributes set" do
+            expect(event).to have_attributes(
+              vaccination_record_outcome: vaccination_record.outcome,
+              vaccination_record_uuid: vaccination_record.uuid,
+              vaccination_record_performed_at: vaccination_record.performed_at,
+              vaccination_record_programme_id: vaccination_record.programme_id,
+              vaccination_record_session_id: vaccination_record.session_id
+            )
+          end
+        end
+      end
+    end
+  end
 end