cellulitis; blistering; case received by gsk via regulatory authority on 27th february 2022 this case was reported by a physician via regulatory authority and described the occurrence of cellulitis in a 1-year-old male patient who received men b nvs (bexsero) for prophylaxis. co-suspect products included meningococcal b recom vaccine + aloh + omv pre-filled syringe device (meningococcal b vaccine pre-filled syringe device) injection syringe for prophylaxis. additional patient notes included fit + well. no allergies.. concomitant products included salbutamol. on 21st february 2022, the patient received bexsero (unknown) and meningococcal b vaccine pre-filled syringe device. on 24th february 2022, 3 days after receiving bexsero and meningococcal b vaccine pre-filled syringe device, the patient experienced cellulitis (serious criteria hospitalization, gsk medically significant and other: serious as per reporter) and blistering (serious criteria hospitalization and other: serious as per reporter). the patient was treated with flucloxacillin and benzylpenicillin. on an unknown date, the outcome of the cellulitis and blistering were recovering/resolving. it was unknown if the reporter considered the cellulitis and blistering to be related to bexsero and meningococcal b vaccine pre-filled syringe device. this report is made by gsk without prejudice and does not imply any admission or liability for the incident or its consequences. additional details were reported as follows: the age at vaccination was unknown. the intensity for the event cellulitis was captured as severe. initial information was received from a physician via regulatory authority on 27th february 2022: cellulitis and blistering. case narrative: received 1yr vaccinations 4 days previously. erythema, swelling developed since on anterior aspect of left thigh. given po flucloxacillin after 2d by gp, then after 4d blistering started and admitted to hospital - diagnosed severe cellulitis around immunisation site. treated with iv benzypenicillin, flucloxacillin. no fevers, eating and drinking ok. reaction do you think this reaction occurred as a result of a mistake made in the administration of the vaccine: "no" drug: bexsero, reason: routine childhood immunization drug: salbutamol, reason: n/a reaction: cellulitis reaction: blistering