This case was reported in a literature article and described the occurrence of kidney transplant rejection in a child subject who received Flu vaccine unspecified for prophylaxis. Co-suspect products included tacrolimus unknown for immunosuppression and Mycophenolate for immunosuppression. The subject's past medical history included kidney transplant. On an unknown date, 141 days after receiving Flu vaccine unspecified, the subject developed kidney transplant rejection. Serious criteria included GSK medically significant. Additional event(s) included treatment noncompliance. The subject was treated with Steroids and IVIG. The outcome of kidney transplant rejection was unknown. The outcome(s) of the additional event(s) included treatment noncompliance (unknown). The investigator considered that there was a reasonable possibility that the kidney transplant rejection may have been caused by Flu vaccine unspecified. Other possible cause(s) of the kidney transplant rejection included Tacrolimus. Relevant Tests: Lab tests were performed on unspecified date. The patient developed de novo donor-specific antibodies (DSA) about 73 days after receiving the influenza vaccine. The patient develop cellular and humoral rejection 141 days post vaccination. Biopsy proven humoral and cellular rejection. The de novo DSA was present for more than 4 months. The patient did develop graft failure about 5 months later due to chronic biopsy proven rejection. Diagnostic results (unless otherwise stated, normal values were not provided): On an unknown date, Biopsy result was see text unknown. On an unknown date, Donor specific antibody present result was see text unknown. Additional information was provided. This case was reported in a literature article and described the "kidney transplant rejection" in a paediatric patient of unspecified gender who was vaccinated with unspecified influenza vaccine (manufacturer unknown) for prophylaxis. The patient was a part of retrospective and descriptive analysis to assess a larger paediatric kidney transplant population and assessed the effect of the seasonal influenza vaccination (currently recommended every year in kidney transplant recipients) on graft outcomes. Specifically, this analysis aimed to study, an association of the vaccine with de novo donor specific anti-HLA antibodies (DSA) formation and kidney transplant rejection, and significantly lengthen the follow-up period compared to previous studies. The study included paediatric kidney transplant patients that were transplanted at the center from 1 January 2006, to 31 December 2015. On an unspecified date, patient was assessed for DSA monitoring prior to the influenza vaccination (results not available). No information on patient's family history or concomitant medication was provided. On an unspecified date, the patient received unspecified influenza vaccine (administration route and site unspecified; dosages unknown; batch number not provided). Age of vaccination was not provided. On an unspecified date, 73 days after vaccination, the patient developed de novo DSA. 141 days after vaccination, the patient developed biopsy proven cellular and humoral rejection. This patient had been living in a shelter during the month prior to rejection and observed and reported non-adherence of the maintenance immunosuppression of mycophenolate and tacrolimus. The de novo DSA was present for more than 4 months. The patient was treated with steroids, plasmapheresis, and IVIG. 275 days after vaccination, the patient developed graft failure due to chronic biopsy-proven rejection. At the time of reporting, the patient was still alive on hemodialysis. The author commented that, "The two remaining patients with de novo DSA and biopsy-proven rejection had multiple other factors that could have contributed to them developing rejection (ie, both had reports of non-compliance. If we were to shorten the time frame to 1-month post-vaccination, only one patient developed DSA in this time frame, and this patient did not develop rejection. Since these patients make up such a small number of vaccinated patients, it seems less likely that these factors are causally related. There were many more vaccinated patients who did not develop rejection, as well as more patients with de novo DSA following vaccination who did not develop rejection." The author concluded, "Our study suggests that being vaccinated post-transplant does not increase the risk of mortality, graft failure, or rejection. This suggests that influenza vaccination is safe in the transplant population and should continue to be encouraged to protect against infection in this vulnerable population." This is 1 of the 3 valid cases reported in the same literature article. Lab Comments: Lab tests were performed on unspecified date. The patient developed de novo donor-specific antibodies (DSA) about 73 days after receiving the influenza vaccine. The patient develop cellular and humoral rejection 141 days post vaccination. Biopsy proven humoral and cellular rejection. The de novo DSA was present for more than 4 months. The patient did develop graft failure about 5 months later due to chronic biopsy proven rejection.