USFDA Med Dev Guidance: In Vitro Diagnostic Tests During Declared Emergencies

Sharan Murugan
Oct 5
3 min read

The U.S. Food and Drug Administration (FDA) has finalized a pivotal guidance addressing how the agency will decide when to begin and end enforcement discretion for unapproved in vitro diagnostic (IVD) tests during a public health emergency declared under Section 564 of the Federal Food, Drug, and Cosmetic Act (FD&C Act).

Under Section 564 of the FD&C Act, the FDA may issue Emergency Use Authorizations (EUAs) for unapproved medical products or for unapproved uses of approved products when an emergency is declared by the U.S. Department of Health and Human Services (HHS).

However, in specific high-pressure scenarios—such as during early phases of a pandemic—the FDA may also implement temporary enforcement policies that allow distribution of certain unapproved tests before formal authorization.

The new guidance defines how the FDA will determine:

When such an enforcement policy is justified; and
When it should be terminated once the public health landscape changes.

In Vitro Diagnostic (IVD) Test: A device used to perform tests on samples taken from the human body (e.g., blood, tissue, saliva) to diagnose or monitor diseases.

Unapproved Use of an Approved Test: When a test is used in a way not covered by its existing authorization (e.g., using a nasal swab instead of a nasopharyngeal sample, or switching to over-the-counter use without FDA clearance).

Core Factors in FDA Decision-Making

According to the guidance, the FDA will consider several interrelated factors before issuing or ending an enforcement policy for unapproved IVDs:

1. Public Health Need

FDA will evaluate the urgency and scale of testing demand:

Availability and capacity of authorized or approved diagnostic tests.
Transmission rates, morbidity, mortality, and population exposure.
Type of emergency (infectious, radiological, chemical, etc.) and speed at which diagnostic capability must be scaled up.
Whether test turnaround time delays pose a significant risk to public health.

For example, during the COVID-19 pandemic, FDA expanded temporary access to laboratory-developed tests (LDTs) when commercial test supplies were insufficient.

2. Benefits and Risks

FDA will weigh potential public health benefits—such as faster detection and improved outbreak management—against risks like false results, misdiagnosis, and inappropriate patient management.

Specific considerations include:

Severity of the disease or condition.
Impact of false negatives or false positives.
Complexity and reliability of the technology used.
Past performance of the manufacturer or test type.

FDA will reassess these factors throughout the emergency, narrowing or expanding enforcement scope as necessary.

3. Availability of Alternatives

If sufficient approved or EUA-authorized tests are available, FDA may choose not to issue a new enforcement policy.

Early in COVID-19, only one authorized diagnostic existed, creating critical shortages.
By contrast, during the mpox response, an existing FDA-cleared Orthopoxvirus test already provided adequate diagnostic coverage for many laboratories.

4. Risk Mitigation Measures

Before exercising enforcement discretion, FDA will evaluate whether risk-reducing factors are in place, such as:

Manufacturer experience with prior EUA or cleared tests.
Participation in recognized performance validation programs (e.g., NIH RADx Tech’s Independent Test Assessment Program ITAP).
Clear labeling disclosures that tests are not FDA-reviewed.
Availability of confirmatory testing pathways.
Submission of an EUA request within a reasonable timeframe.

Additionally, the draft guidance on Validation of Certain In Vitro Diagnostic Devices for Emerging Pathogens During a Section 564 Declared Emergency, issued earlier in 2025, provides recommended validation approaches that may apply to tests offered under future enforcement policies.

Stakeholders can submit comments on this guidance at any time through the Federal Register docket FDA-2023-D-5365. The September 23 2025 guidance on enforcement policies for IVDs marks a critical evolution in FDA’s public health preparedness strategy.

It institutionalizes a transparent, evidence-based approach for balancing access and accuracy of diagnostic testing in national emergencies. By outlining clear decision factors, FDA aims to ensure that the right tests reach clinicians and patients—quickly, safely, and responsibly—whenever the next public health crisis emerges.