What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINC

LOINC Code 66385-6: Has the child had a serious reaction to a vaccine in the past [PhenX]

Name: LOINC Code 66385-6: Has the child had a serious reaction to a vaccine in the past [PhenX]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:45.460Z

66385-6 is a LOINC code used to identify Has the child had a serious reaction to a vaccine in the past [PhenX] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Has the child had a serious reaction to a vaccine in the past. It is commonly used with the system or sample type ^Patient.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Has the child had a serious reaction to a vaccine in the past. It is commonly used with the system or sample type ^Patient.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: TRIAL
Method: PhenX

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Has the child had a serious reaction to a vaccine in the past [PhenX]
Has the child had a serious reaction to a vaccine in the past
Child vaccine reaction; Finding; Findings; Last; Ordinal; Point in time; QL; Qual; Qualitative; Random; React; Rxn; Screen

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

Has the child had a serious reaction to a vaccine in the past [PhenX]Child vaccine reaction PhenXHas the child had a serious reaction to a vaccine in the pastPHENXFindPt^Patient

Frequently asked questions

Code details

Code66385-6

SystemLOINC

Display nameHas the child had a serious reaction to a vaccine in the past [PhenX]

DescriptionHas the child had a serious reaction to a vaccine in the past

Short nameChild vaccine reaction PhenX

ComponentHas the child had a serious reaction to a vaccine in the past

PropertyFind

TimingPt

System (specimen)^Patient

ScaleOrd

MethodPhenX

ClassPHENX

StatusTRIAL

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.38

Last changed2.65

Part names

Has the child had a serious reaction to a vaccine in the pastFindPt^PatientOrdPhenXFindingPoint in time (spot)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.