Infanrix 1st dose Dec2019, booster Jul2020; Pediarix 4th dose administered / 2nd dose Dtap; Pediarix 1st dose 29oct2019, 2nd  02jan2019, 3rd dose 28 Jan 2019; Pediarix 1st dose 29oct2019, 2nd  02jan2019; This case was reported by a nurse via call center representative and described the occurrence of drug dose administration interval too long in a 5-month-old male patient who received DTPa (DTaP vaccine) for prophylaxis.   Co-suspect products included DTPa-HBV-IPV (Pediarix) (batch number J947T, expiry date 30th May 2021) for prophylaxis, dtpa-hbv-ipv vaccine pre-filled syringe device (Pediarix Pre-Filled Syringe Device) injection syringe for prophylaxis, DTPa-HBV-IPV (Pediarix) for prophylaxis, dtpa-hbv-ipv vaccine pre-filled syringe device (Pediarix Pre-Filled Syringe Device) injection syringe for prophylaxis, DTPa-HBV-IPV (Pediarix) for prophylaxis and dtpa-hbv-ipv vaccine pre-filled syringe device (Pediarix Pre-Filled Syringe Device) injection syringe for prophylaxis.   Concomitant products included PEDIARIX.   On 30th July 2020, the patient received the 6th dose of DTaP vaccine. On 29th October 2019, the patient received the 4th dose of Pediarix and Pediarix Pre-Filled Syringe Device. On 28th January 2019, the patient received the 3rd dose of Pediarix and Pediarix Pre-Filled Syringe Device. On 2nd January 2019, the patient received the 2nd dose of Pediarix and Pediarix Pre-Filled Syringe Device. On 2nd January 2019, not applicable after receiving DTaP vaccine, Pediarix, Pediarix Pre-Filled Syringe Device, Pediarix and Pediarix Pre-Filled Syringe Device and unknown after receiving Pediarix and Pediarix Pre-Filled Syringe Device, the patient experienced drug dose administration interval too long. On 28th January 2019, the patient experienced drug dose administration interval too short. On 29th October 2019, the patient experienced extra dose administered. On 30th July 2020, the patient experienced drug dose administration interval too short. On an unknown date, the outcome of the drug dose administration interval too long, drug dose administration interval too short, extra dose administered and drug dose administration interval too short were unknown.     This report is made by GSK without prejudice and does not imply any admission or liability for the incident or its consequences.   Additional Information: GSK receipt date: 6-Sept-2022 Reporter's comment: The nurse reported that the patient received 4 doses of Pediarix and 2 doses of Dtap only vaccine (one of them being Infanrix and the other one unknown) prior to age 4. The reporter asked that it was ok  to give Infanrix (DTAP) to a 4 year old that had received 6 doses prior to age 4. As per Agency, no more than 6 doses of DT should be given before age of 7 r/t adverse reactions but dose after 4 was required for school. The 4th dose of Pediarix was corresponded to Infanrix but registered nurse reported it as Pediarix dose. On 19th December 2019, the patient received 5th dose of Infanrix. The Vaccine Administration Facility was the same as Primary Reporter. The reporter consented to follow-up. Additional supportive information: The patient received 2nd dose of Pediarix later than the recommended interval and 3rd dose of Pediarix earlier than the recommended interval, which led to lengthening of vaccine schedule and shortening of vaccine schedule. The patient received 4th dose of Pediarix, which led to extra dose administered. The patient received 6th Dtap vaccine earlier than the recommended interval, which led to shortening of vaccine schedule. For 1st four doses of Pediarix local schedule was followed (as 2,4 and 6 months of age) and for last 2 doses of Dtap, Infanrix's local schedule was followed, considered both doses as booster as (one booster 15-20 months of age and another booster in 4 to 6 years of age).