Background Early outcomes after human immunodeficiency virus (HIV) + liver transplantation (LT) are encouraging, but data are lacking regarding long-term outcomes and comparisons with matched HIV− patients. Methods We examined outcomes among 180 HIV+ LT, and compared outcomes to matched HIV− counterfactuals (Scientific Registry of Transplant Recipients 2002-2011). Iterative expanding radius matching (1:10) on recipient age, race, body mass index, hepatitis C virus (HCV), model for end-stage liver disease score, and acute rejection; and donor age and race, cold ischemia time, and year of transplant. Patient survival and graft survival were estimated using Kaplan-Meier methodology and compared using log-rank and Cox proportional hazards. Subgroup analyses were performed by transplant era (early: 2002-2007 vs modern: 2008-2011) and HCV infection status. Results Compared to matched HIV− controls, HIV+ LT recipients had a 1.68-fold increased risk for death (adjusted hazard ratio [aHR], 1.68, 95% confidence interval [95% CI], 1.28-2.20; P < 0.001), and a 1.70-fold increased risk for graft loss (aHR, 1.70; 95% CI, 1.31-2.20; P < 0.001). These differences persisted independent of HCV infection status. However, in the modern transplant era risk for death (aHR, 1.11; 95% CI, 0.52-2.35; P = 0.79) and graft loss (aHR, 0.89; 95% CI, 0.42-1.88; P = 0.77) were similar between monoinfected and uninfected LT recipients. In contrast, independent of transplant era, coinfected LT recipients had increased risk for death (aHR, 2.24; 95% CI, 1.43-3.53; P < 0.001) and graft loss (aHR, 2.07; 95% CI, 1.33-3.22; P = 0.001) compared to HCV+ alone LT recipients. Conclusions These results suggest that outcomes among monoinfected HIV+ LT recipients have improved over time. However, outcomes among HIV+ LT recipients coinfected with HCV remain concerning and motivate future survival benefit studies.

This guidance was developed to summarize current approaches to the potential transmission of swine-derived organisms to xenograft recipients, health care providers, or the public in clinical xenotransplantation. Limited specific data are available on the zoonotic potential of pig pathogens. It is anticipated that the risk of zoonotic infection in xenograft recipients will be determined by organisms present in source animals and relate to the nature and intensity of the immunosuppression used to maintain xenograft function. Based on experience in allotransplantation and with preclinical models, viral infections are of greatest concern, including porcine cytomegalovirus, porcine lymphotropic herpesvirus, and porcine endogenous retroviruses. Sensitive and specific microbiological assays are required for routine microbiological surveillance of source animals and xenograft recipients. Archiving of blood samples from recipients, contacts, and hospital staff may provide a basis for microbiological investigations if infectious syndromes develop. Carefully implemented infection control practices are required to prevent zoonotic pathogen exposures by clinical care providers. Informed consent practices for recipients and their close contacts must convey the lack of specific data for infectious risk assessment. Available data suggest that infectious risks of xenotransplantation are manageable and that clinical trials can advance with carefully developed protocols for pretransplant assessment, syndrome evaluation, and microbiological monitoring.

Respiratory viruses—including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19), respiratory syncytial virus (RSV), and influenza—pose significant risks to immunocompromised patients, who experience attenuated vaccine responses and higher morbidity. To address evolving vaccine recommendations for the 2025–2026 season, the Infectious Diseases Society of America (IDSA), in collaboration with the Vaccine Integrity Project (VIP) and partner organizations, developed rapid guidelines for US-licensed vaccines targeting these viruses. The guideline applies to adults and children with compromised immunity due to hematologic malignancy, solid organ or hematopoietic cell transplantation, autoimmune disease on immunosuppressants, human immunodeficienty virus with severe immunosuppression, and similar conditions. Strong recommendations, supported by moderate certainty evidence, endorse timely administration of age-appropriate COVID-19, RSV, and influenza vaccines, with guidance on optimal timing relative to immunosuppressive therapy and transplantation. Coadministration of these vaccines is considered appropriate. Research gaps remain in immunogenicity, durability, and clinical effectiveness, particularly for patients receiving B-cell–depleting therapies or early post-transplant. Priority areas include defining correlates of protection, optimizing vaccine schedules, evaluating high-dose or adjuvanted formulations, and improving real-world effectiveness and safety data. Equity and access strategies are essential to ensure uptake among vulnerable populations. These guidelines aim to support evidence-based decision-making and highlight the need for harmonized, multi-virus research to inform tailored vaccination strategies for immunocompromised individuals.

Seasonal influenza vaccination elicits hemagglutinin (HA)-specific CD27 ⁺ memory B cells (Bmem) that differ in expression of T-bet, BACH2 and TCF7. T-bet ^hi BACH2 ^lo TCF7 ^lo Bmem are transcriptionally similar to effector-like memory cells while T-bet ^lo BACH2 ⁺ TCF7 ⁺ Bmem exhibit stem-like central memory properties. T-bet ^hi Bmem do not express plasma cell-specific transcription factors but do exhibit transcriptional, epigenetic, metabolic and functional changes that poise the cells for antibody production. Consistent with these changes, D7 HA ⁺ T-bet ^hi Bmem express intracellular immunoglobulin and T-bet ^hi Bmem differentiate more rapidly into ASCs in vitro. The T-bet ^hi Bmem response positively correlates with long-lived humoral immunity and clonotypes from T-bet ^hi Bmem are represented in the early secondary ASC response to repeat vaccination, suggesting that this effector-like population can be used to predict vaccine durability and recall potential.