2 adjuvant vials to reconstitute 1antigen vial; 2 Shingrix adjuvant vials to reconstitute 1 Shingrix antigen vial, because there was not enough vaccine to reach the correct concentration of 0.5ml from the first adjuvant vial; Only 0.4ml once mixed with 1st adjuvant; This non-serious case was reported by a pharmacist via call center representative and described the occurrence of inappropriate preparation of medication in a male patient who received Herpes zoster (Shingrix) (batch number 73XT7, expiry date 18-JUN-2024) for prophylaxis. This case was associated with a product complaint.   On an unknown date, the patient received Shingrix .5 mg. On an unknown date, an unknown time after receiving Shingrix, the patient experienced inappropriate preparation of medication (Verbatim: 2 adjuvant vials to reconstitute 1antigen vial), wrong technique in product usage process (Verbatim: 2 Shingrix adjuvant vials to reconstitute 1 Shingrix antigen vial, because there was not enough vaccine to reach the correct concentration of 0.5ml from the first adjuvant vial) and pharmaceutical product complaint (Verbatim: Only 0.4ml once mixed with 1st adjuvant). The outcome of the inappropriate preparation of medication, wrong technique in product usage process and pharmaceutical product complaint were unknown.   Additional Information: GSK receipt date: 05-APR-2023 and 06-APR-2023 The reporter was a pharmacist and an experienced user of Shingrix, that reports that he had to use 2 Shingrix adjuvant vials to reconstitute 1 Shingrix antigen vial, because there was not enough vaccine to reach the correct concentration of 0.5ml from the first adjuvant vial due to a low fill problem and then administered this reconstituted vaccine to a patient (no other identifying factors are available for the patient). The reporter was not exactly certain, but think the volume of vaccine was only 0.4ml once reconstituted with the first adjuvant vial. The reporter did review product instructions for use step by step from the product information with the health care professional (HCP).  The defect was discovered during preparation.  The mixing was performed not vigorously, but gently to avoid air bubbles, but enough to get into solution.  The product was administered once he had enough vaccine volume.  The adjuvant vial was impacted.  The vial was discarded already, so they were unable to send pictures of the defect.  The HCP did not know exactly, but HCP thinks about 0.4 ml, but not enough to reach 0.5 ml and 1cc size syringe was used. The syringe had harsh marks, and they were marked at 0.001ml intervals.  The reporter experienced a low fill problem with this product before, but it had been several years.  The air was nor injected into the vial. The reporter did not observed any leaks or cracks in vial. The HCP had already discarded the suspect vaccines as this happened last week (no specific date), and we were closed when he called the first time. The reporter asked to send replacement as urgent for 1 Shingrix Single Vial dose pack to the pharmacy.  The reporter did not asked for consent to follow up with HCP. The patient received Shingrix vaccine with 2 Shingrix adjuvant vials to reconstitute 1 Shingrix antigen vial, which led to inappropriate preparation of medication, wrong technique in product usage process and pharmaceutical product complaint.