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Report #2884405

Received Feb 5, 2026

A note on interpretation. VAERS reports are unverified and may be incomplete or coincidental. A report does not establish that a vaccine caused an event, and counts should not be used to calculate incidence or infer causation. Full disclaimer

Overview

Sex
Unknown
Age
Age unknown
State
CT
Recovered
Unknown
Vaccinated
—
Onset
—
Days to onset
—
Hospital days
—

Vaccines (1)

TypeNameManufacturerDoseLotRoute / Site
YFYELLOW FEVER (YF-VAX)SANOFI PASTEURUNK—OT

Symptoms (2)

No adverse eventProduct preparation error

Symptom narrative

incorrect diluent was used to reconstitute YF-VAX and administered to a patient, with no reported adverse event; Initial information received on 03-Feb-2026 regarding an unsolicited valid non-serious case received from a physician. This case an unknown demographics patient who received incorrect diluent was used to reconstitute Yellow Fever Vaccine [YF-VAX] and administered to a patient, with no reported adverse event. The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided. On an unknown date, the patient received a unknown dose of suspect Yellow Fever Vaccine Solution for injection (strength, route, batch number and expiry date: unknown) in unknown administration site for prophylactic vaccination. On an unknown date incorrect diluent was used to reconstitute yf-vax and administered to a patient, with no reported adverse event (product preparation error) (latency: same day). It was reported "The diluent for MMR (sterile water) was used, not Sodium Chloride" Action taken: not applicable. This suspected adverse reaction report is submitted and classified as a medication error solely and exclusively to ensure the marketing authorization holder's compliance with the requirements set out in the Directive 2001/83/EC and Module VI of the Good Pharmacovigilance Practices. The classification as a medical error is in no way intended, nor should it be interpreted or construed as an allegation or claim made by the marketing authorization holder that any third party has contributed to or is to be held liable for the occurrence of this medication error.