Background/Objectives: Influenza is a viral infection affecting up to 20% of the general population annually. Solid organ transplant recipients have a higher morbidity and mortality risk, as well as a greater likelihood of severe disease complications. Vaccination against the influenza virus is a safe and recommended prophylaxis; however, immunosuppression and high comorbidity burdens impair the immune response. We assessed the efficacy, safety, and humoral response to influenza vaccine in a population of kidney transplant recipients (KTx). Methods: Adult KTx recipients at least 6 months post-KTx were divided into vaccinated (vKTx) and non-vaccinated (nvKTx) groups based on consent for vaccination. The vKTx group received one dose of quadrivalent split virion inactivated vaccine (Vaxigrip Tetra Sanofi Pasteur). Subjective symptoms and side effects were recorded in paper journals. Antibody levels were assessed with ELISA prior to and 3 months following vaccination. Serum creatinine and proteinuria were assessed prior to vaccination as well as 3 and 6 months after. Results: Of 450 recruited KTx recipients, 91 in the vKTx group and 36 in the nvKTx group of comparable age, KTx vintage, and graft function were included in the study. Graft function and proteinuria remained stable in both groups. The vKTx group experienced no severe adverse events. The most common complaints were general malaise (20.5%) and injection site pain (10.3%). Overall infection rates were comparable, yet the vKTx group experienced significantly fewer serious infections (11.4% vs. 32.3%, p = 0.01); the vKTx group showed a greater increase of Influenza A IgM (p = 0.05) and Influenza B IgG (p = 0.01) compared with the nvKTx group. Conclusions: Influenza vaccination prevents severe infections in KTx recipients, with good serological response and no impact on graft function or severe adverse events.

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels’ reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53–6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication’s occurrence.