Received Dec 18, 2025
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| SMALL | SMALLPOX (ACAM2000) | EMERGENT BIOSOLUTIONS | UNK | — | — |
Tested RPR positive; This initial spontaneous case report was received on 10-Dec-2025 from the other healthcare professional about a patient who was vaccinated with ACAM2000 [Smallpox (Vaccinia) Vaccine, Live; lot number unknown). It was reported that the patient was "tested rapid plasma reagin (RPR) positive" (PT: Syphilis test positive). On 07-Nov-2025, ACAM2000 was administered to the patient, for immunization. It was reported that the patient initially tested positive for RPR but negative for syphilis-specific antibodies. The Center's Responsible Physician (CRP) attributed this to a biological false positive, potentially secondary to recent vaccination. Following the physician's order for repeat testing, the patient provided a new sample on 10-Dec-2025. Notably, the patient has completed two donations as part of the vaccinia program. There was no other lab/imaging reported. The outcome of reported event was unknown. No additional information was reported.
Comments: Patient's history: unknown
Test Date: 2025; Test Name: Rapid plasma reagin; Result Unstructured Data: Positive; Test Date: 20251210; Test Name: Rapid plasma reagin; Result Unstructured Data: Unknown; Test Date: 2025; Test Name: Syphilis test; Result Unstructured Data: Negative; Test Date: 20251210; Test Name: Syphilis test; Result Unstructured Data: Unknown