Only the DTaP-IPV component was administered to the patient/The Hib component was not yet administered, with no reported adverse event; Initial information received on 21-Jan-2025 regarding an unsolicited valid non-serious case received from a nurse. This case involves a 5 months old male patient to whom only the dtap-ipv component of diphtheria/tetanus/5 hybrid AC pertussis/IPV(VERO)/HIB(PRP/T) vaccine [Pentacel (Vero)] was administered to the patient/the hib component was not yet administered, with no reported adverse event. The patient’s past medical history, medical treatment(s), vaccination(s) and family history were not provided. Concomitant medications included Pneumococcal vaccine conj 20v (CRM197) (Prevnar 20) for Immunisation. On 21-Jan-2025, only the dtap-ipv component was administered to the patient at unknown dose of diphtheria/tetanus/5 hybrid AC pertussis/IPV(VERO)/HIB(PRP/T) vaccine, Powder and suspension for suspension for injection (lot UK167AA; Expiration date: 20-Oct-2025 strength not reported) via intramuscular route in unknown administration site for Immunization, hib component was not yet administered, with no reported adverse event (single component of a two-component product administered) (latency: on same day). 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.