FDA Authorizes PCR Assay That Distinguishes Herpes, VZV, and Mpox

Originally surfaced August 6, 2026, when the Federal Register published FDA's notice of the authorization.

FDA has authorized a laboratory PCR assay that can distinguish several viruses capable of causing similar-looking skin lesions. The date detail matters: FDA issued the emergency use authorization on July 9, 2026. The Federal Register notice announcing and documenting it was published August 6.

The product is Seegene USA's Allplex HSV-1&2/VZV/MPXV Assay. It simultaneously detects and differentiates nucleic acid from herpes simplex virus type 1, herpes simplex virus type 2, varicella-zoster virus, and monkeypox virus targets. The authorized specimen is a swab from an acute pustular or vesicular rash in a person whose healthcare provider suspects an infection consistent with mpox.

That makes this a differential-diagnosis story, not a new consumer screening product.

Why one lesion-swab assay can be useful

FDA's authorization letter says infections caused by mpox virus, HSV-1, HSV-2, and VZV can have similar clinical presentations. A blistering or ulcerative lesion cannot always be assigned to the correct virus by appearance alone. A multiplex assay lets a qualified laboratory test the same clinical specimen for those targets and report which viral nucleic acid was detected.

The assay uses real-time PCR and reports qualitative results. In other words, it is designed to detect and differentiate specified viral targets, not measure a general viral load or predict how severe an illness will become.

The scope is narrow. Testing is limited to laboratories certified under the Clinical Laboratory Improvement Amendments that meet requirements for high-complexity testing. The assay is not intended for cerebrospinal fluid or prenatal screening. FDA also says a negative result does not rule out infection and should not be the sole basis for treatment or other patient-management decisions.

What emergency use authorization means here

This product has been authorized under an emergency use authorization, or EUA. It has not been FDA cleared or approved. The authorization remains tied to the federal declaration supporting emergency use of in vitro diagnostics for mpox and can be revised, revoked, or end when that declaration is terminated.

FDA concluded that the statutory EUA criteria were met, including that the assay may be effective for the authorized use and that its known and potential benefits outweigh its known and potential risks when used within that scope. That is different from ordinary premarket clearance or approval, and the distinction should stay visible whenever the test is described.

The authorization also does not turn the assay into an at-home or direct-to-consumer test. Collection, laboratory setting, authorized instruments, operator training, clinical context, and public-health reporting conditions are all part of the authorized use.

This is not the same as a herpes antibody blood test

LabTestSuperstore's HSV-1 and HSV-2 herpes test is a blood test that looks for type-specific antibodies. It answers a different question from the newly authorized lesion-swab PCR assay.

CDC explains that when a sore is present, a healthcare provider can take a sample or swab from it for testing. When sores are not present, a blood test may be used to look for HSV antibodies. Antibody blood testing cannot identify mpox or VZV, cannot tell whether an active lesion is caused by HSV, and does not substitute for PCR performed on a lesion specimen.

That distinction is especially important when symptoms overlap. The STD symptoms overview can provide background, but a symptom list cannot determine which infection is present. Lesions, recent exposure, pregnancy, severe symptoms, or suspected mpox require clinical evaluation rather than an attempt to match a picture or blood antibody result to a diagnosis.

The clean takeaway

The news is not that one test now screens everyone for herpes and mpox. It is that FDA has authorized a high-complexity laboratory tool designed to separate several viral causes of similar lesions from one swab specimen.

The useful boundary is equally clear. Lesion PCR and antibody blood testing are different tools, used on different specimens, for different clinical questions. The new EUA expands a laboratory's differential-diagnosis options. It does not make visual self-diagnosis reliable, replace clinical interpretation, or convert a consumer HSV antibody test into an active-lesion test.

This article is editorial commentary and is not medical advice. It has not been reviewed by a physician and should not be used to decide whether a lesion is herpes, chickenpox, shingles, or mpox, or to make decisions about diagnosis, isolation, treatment, pregnancy care, or testing frequency.