Vaccines save lives. They are integral to reducing the morbidity and mortality of vaccine-preventable infections in solid organ transplant recipients. Pre-transplant vaccination provides a unique opportunity for administration of live, viral vaccines, and enhanced vaccine efficacy, compared to the post-transplant period with decreased vaccine response due to immunosuppression.

We discuss a general approach to pre- and post-transplant vaccination in solid organ transplant candidates and recipients. We then review guideline statements and recent literature related to individual vaccines, including the recently developed respiratory syncytial virus vaccine. Travel and occupation-related vaccines are also discussed.

The challenge of vaccination for immunocompromised patients expands as the prevalence of immunocompromised adults rises, and immunocompromised patients are frequently excluded from vaccine trials. In an age of vaccine hesitancy and reemerging vaccine-preventable infections, well-powered, prospective studies are needed to evaluate the clinical effectiveness of vaccines in solid organ transplant candidates and recipients.

The purpose of this review was to examine new evidence since the authors' 2019 guidelines for cervical cancer (CC) screening in non-HIV immunocompromised persons and to provide updated recommendations based on literature review and expert opinion. In addition, human papillomavirus (HPV) vaccine efficacy in these populations was reviewed.

A literature search was performed similar to the authors' previous publication but was conducted through March 2023. Risk of CC, squamous intraepithelial lesions, and HPV infection in those living with solid organ transplant (SOT), end-stage renal disease (ESRD), hematopoietic stem cell transplant (HSCT), and autoimmune diseases (AID), specifically systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD) with addition of multiple sclerosis (MS) were researched. This update also summarizes data available on newer disease-modifying therapies (DMTs) including monoclonal antibodies (MABs). The authors then made recommendations for HPV vaccine administration, and screening using either general population guidelines or increased surveillance, the latter based on following current recommendations for women living with HIV. Additionally, the literature search included antibody response to HPV vaccines and recommendations for their administration for these same conditions.

Based on the reviewed risks, evidence continued to support those persons living with SOT, ESRD, HSCT, and SLE, whether on immunosuppressant therapy or not, had an increased risk of HPV, squamous intraepithelial lesions, and CC whereas there was weak evidence that those persons with IBD, RA, and MS not on immunosuppressants were at risk. Data on persons using DMT/MAB were conflicting. Data showed that patients on certain immunosuppressants had lower antibody titers following HPV vaccination. There were no studies on HPV vaccine efficacy.

Following US Center for Disease Control and Prevention HIV Cervical cancer screening (CCS) guidelines is recommended for the following: SOT, ESRD, HSCT, and SLE whether on immunosuppressants or not, and IBD, RA, and MS on immunosuppressants. Shared decision-making about increased surveillance for IBD and RA not on immunosuppressants and persons on any DMT or MAB is reasonable based on conflicting data. Human papillomavirus vaccination should not change the recommendations for increased CC surveillance. A 3-dose series of the HPV vaccine is recommended for all age-eligible patients starting at 9 years of age, with catch-up to 26 years of age. Vaccination from age 27 up to age 45 years per Advisory Committee on Immunization Practices guidelines should be considered in shared decision-making. When possible, HPV vaccine series should be initiated and completed before SOT or initiation of DMT/MAB. For HSCT, the vaccine series should be readministered along with other childhood vaccines.

Kidney transplantation is the preferred treatment for patients with advanced chronic kidney disease and end-stage kidney disease, offering superior quality of life and survival compared to dialysis. This manuscript provides an updated overview of post-transplant care, highlighting recent advancements and current practices to assist generalists in managing these patients. It covers key areas such as immunosuppression strategies, drug interactions, and the management of transplant-specific acute kidney injury. The focus includes the use of sodium-glucose cotransporter-2 inhibitors and cell-free DNA monitoring for evaluating allograft health and immune-mediated injury. The manuscript reviews the fundamentals of immunosuppression, including both induction and maintenance therapies, and underscores the importance of monitoring kidney function, as well as addressing hypertension, diabetes, and infections. It also provides recommendations for vaccinations and cancer screening tailored to kidney transplant recipients and emphasizes lifestyle management strategies, such as exercise and sodium intake, to reduce post-transplant complications.

Liver transplantation (LT) is a well-established therapy for patients with decompensated cirrhosis and early-stage hepatocellular carcinoma. Liver transplantation activity varies sharply across Latin American (LATAM) countries due to differences in resources, expertise, and funding and local attitudes toward organ donation and transplantation. This current guidance of postoperative care after LT is the first position paper of the Latin American Association for the Study of the Liver (ALEH) Special Interest Group (SIG), drawing evidence-based recommendations regarding immediate and long-term postoperative care of LT recipients, taking into consideration their applicability in Latin America.

Patients with cirrhosis and liver transplant recipients are at increased risk of infections. Malnutrition, multiple hospital admissions, immune dysfunction related to cirrhosis, and immunosuppressive agents used for liver transplantation predispose the recipient to various life-threatening infections. Some of these infections are preventable with vaccines. With the COVID-19 pandemic, there has been an accelerated research in vaccination technology and platforms, which in turn may also improve awareness of physicians regarding this healthy and often ignored aspect of management of patients with cirrhosis and transplant recipients. The organ transplant candidates should complete the recommended vaccination schedule as early as possible (especially patients with compensated cirrhosis) or at least during their pretransplant work-up so as to prevent or reduce the severity of various infections.

Immunocompromised patients are more susceptible to infections. Although they have reduced immune response to vaccines, it is still essential to prioritize immunizations as one strategy to potentially reduce the impact of pneumonia in this vulnerable population. Response to immunizations in immunocompromised patients can be enhanced by increasing the dose of vaccines (eg, influenza) or by increasing the number of doses (eg, coronavirus disease 2019). Prophylactic use of antimicrobials, control of risk factors (avoidance of smoking), and stabilization of underlying conditions (eg, chronic obstructive pulmonary disease) can also have a beneficial effect to reduce the likelihood of pneumonia in the immunocompromised host.

Heart transplantation has significantly improved survival and enhanced the quality of life of patients with end-stage heart failure. Successful long-term outcomes are predicated on a collaborative effort among patients, transplant teams, and primary care providers (PCPs). Notably, PCPs are increasingly pivotal in post-transplant care, engaging in annual assessments, early recognition of complications, and referral, thus minimizing morbidity and mortality. This article highlights key considerations for PCPs, including indications for heart transplant, immunosuppressive therapy and infection prophylaxis, management of post-transplant complications, psychosocial and lifestyle adjustment, and family planning. This roadmap aims to empower PCPs to deliver optimal care and improve long-term outcomes for heart transplant recipients.

Heplisav-B, a CpG-adjuvanted recombinant hepatitis B virus (HBV) vaccine, has a higher seroprotection rate and immunogenicity than the conventional HBV vaccine. This study aimed to identify the predictors of HBV seroprotection post-transplantation in thoracic organ transplant recipients who received Heplisav-B.

We conducted a retrospective study of adult thoracic organ (heart and lung) transplant recipients at Mayo Clinic sites in Minnesota, Arizona, and Florida between January 2020 and August 2023. Patients who completed Heplisav-B series were classified into three strategies: strategy A (completed 2 doses of Heplisav-B pre-transplantation with achieved seroprotection pre-transplantation), strategy B (received first dose of Heplisav-B pre-transplantation and second dose of Heplisav-B post-transplantation), and strategy C (completed 2 doses of Heplisav-B post-transplantation). HBV seroprotection was defined as HBsAb ≥10 IU/L.

A total of 154 thoracic organ transplant recipients completed Heplisav-B vaccine series. Post-transplant seroprotection was highest in strategy A, followed by strategy B and strategy C (54/76 [71 %] vs. 18/39 [46 %] vs. 14/39 [36 %]; p < 0.001). Multivariate logistic regression analysis identified two independent factors predicting lack of HBV seroprotection post-transplantation; both were related to Heplisav-B schedule: strategy B (adjusted odds ratio [aOR], 2.482; 95 % confidence interval [CI] 1.085 5.679; p = 0.031), and strategy C (aOR 4.963; 95 % CI 2.106 11.697; p < 0.001).

The vaccine schedule significantly predicts HBV seroprotection in adult thoracic organ transplant recipients. Our data supports the recommendation that pre-transplantation Heplisav-B to achieve HBsAb ≥10 IU/L is the optimal vaccination schedule to maintain an HBsAb level of ≥10 IU/L post-transplantation. Further studies are needed to determine whether this observation can be replicated in non-thoracic organ transplant recipients or pediatric populations.

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).

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.

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.

Influenza vaccination prevents severe infections in KTx recipients, with good serological response and no impact on graft function or severe adverse events.

Children and adolescents who are being treated or have been treated for acute leukemia have a secondary immunodeficiency linked to chemotherapy, resulting in an increased risk of infections. Some of which can be prevented by vaccination but its effectiveness is not optimal during chemotherapy. Upon cessation of chemotherapy, the time required for immune reconstitution varies from three months to more than a year, depending on lymphocyte subpopulations, the patient's age, and the intensity of the treatment received. Although they may have regained their immune functions, studies show that most patients have lost part of their vaccine-induced protection post-chemotherapy and require booster doses of vaccines. Most practitioners agree on the importance of vaccinating or revaccinating these children, but practices are heterogeneous among pediatric hematologist-oncologists in France. Based on a practice study and a recent review of the literature, this work aims to propose new French recommendations for the vaccination strategy to be adopted for children and adolescents treated or recently treated for acute leukemia, excluding allogeneic transplant recipients, in 2024. These recommendations specifically include the vaccination protocols for human papillomavirus and meningococcal infections but do not address the COVID-19 vaccination, as its guidelines are subject to rapid changes.

Many transplant programs worldwide are likely to impose vaccine mandates for pediatric solid organ transplant candidates; some already do. Three potential benefits that advocates invoke to justify mandates are improved patient outcomes, efficient organ allocation, and contributions to community protection. We show that none of these benefits can justify mandates. The medical benefits of mandates are unlikely to outweigh the risks of denying life-saving care, mandates threaten trust and equity in organ allocation, and the impact on community protection is likely negligible, while the burden on unvaccinated children would be disproportionate. We also reject the claim that clinician burdens in dealing with vaccine refusers are good reasons for mandates, and point out, to the contrary, that the potential political backlash to mandates is a good reason for restraint. Rather, we argue that vaccine mandates for pediatric transplant candidates should be a last resort; they should only be considered after all evidence-based noncoercive measures have been exhausted, and after mandates for transplant professionals and staff are in place. Since there is little evidence that all such measures have been attempted, it is premature to consider vaccine mandates.

Infections preventable by live virus vaccines are surging in the setting of decreased herd immunity. Many children with chronic liver diseases (CLDs) are unimmunized and at increased risk for infection due to guidelines recommending against live vaccines within 4 weeks pretransplant. This prospective study of 21 children with CLD and 13 healthy controls defined the timing of measles virus and varicella-zoster virus (VZV) RNA- and DNA-emia following vaccination and compared immune responses to measles and varicella vaccines in both groups. Measles virus RNA and VZV DNA real-time PCR were measured weekly following vaccination; measles virus RNA was undetectable in all by 14 days postvaccination, but VZV DNA, which can be managed with antivirals, was detected in 1 child in the CLD group at 21 days and 1 control at 28 days postvaccination. Humoral or cell-mediated vaccine response was 100% to measles virus and 94% to VZV in the CLD group postvaccination, whereas it was 100% to both vaccines in controls. Our pilot study suggests that both live vaccines can be safely and effectively administered up to 14 days prior to transplantation in children with CLD. We anticipate this will improve vaccination rates and thus decrease rates of vaccine-preventable infections in vulnerable children with CLD.

Recently, live-attenuated measles, rubella, varicella, and mumps vaccines have been administered to carefully selected post-liver transplant patients. Although attention has been focused on post-vaccination antibody titers and adverse events, the real-life clinical benefits remain unclear. A comprehensive analysis of breakthrough infections and natural boosters (asymptomatic cases with significant elevation in virus antibody titers) following immunization post-liver transplantation was conducted from 2002-2023, exploring the timing, frequency, correlation with domestic outbreaks, and degree of antibody elevation. During the median 10-year observation period among 68 post-liver transplant patients, breakthrough infections occurred only in chickenpox, with 7 mild cases (1 episode/64 person-years). A total of 59 natural booster episodes (1, 5, 20, and 33 for measles, rubella, chickenpox, and mumps, respectively) were observed, with incidence rates of 1 per 569, 110, 22, and 17 person-years, respectively. The timing of natural boosters closely correlated with domestic outbreaks (P < .05 in chickenpox and mumps), influenced by local vaccine coverage. The degree of antibody elevation was significantly higher in individuals with breakthrough infections than in those with natural boosters (P < .05). These findings suggest that immunization with live-attenuated vaccines for post-liver transplant patients has demonstrated clinical benefits. Furthermore, mass vaccination has a positive impact on post-transplant patient outcomes.

A recent conditional recommendation suggests considering live-attenuated vaccines for solid organ transplant recipients, yet the conditions of their safe and effective administration remain unclear.

This prospective study was conducted at Keio University Hospital from 2002 to August 2023. We gave a live-attenuated vaccine to liver transplant (LT) recipients fulfilling criteria for live-attenuated vaccines, including criteria for humoral and cell-mediated immunity. Patient background information, immunization date, vaccine strain, immunosuppressive agents at the time of vaccination, and antibody titers were collected. Factors related to primary and secondary vaccine failure were evaluated to enhance the effectiveness of the live-attenuated vaccine program after LT.

Among 67 LT recipients, 54, 55, 47, and 55 received at least one dose of live-attenuated vaccine for measles, rubella, varicella, and mumps, respectively. The difference in vaccine strains, but not the use of two or more immunosuppressive agents, was associated with a lower risk of vaccine failures. Measles vaccine with the AIK-C strain exhibited significantly lower primary and secondary failure rates than the CAM-70 strain (1/38 vs. 4/16, odds ratio: 0.08, 95 % confidence interval [CI]: 0.01-0.80, p = 0.02, and hazard ratio: 0.54, 95 % CI: 0.34-0.85, p = 0.01, respectively). No primary failures were observed with the TO-336 strain of rubella, whereas 4 of 10 LT recipients with the Matsuura strain of rubella did not seroconvert. For mumps, the Hoshino strain showed lower primary failure rates than the Torii strain (15/52 vs. 3/3, p = 0.03).

According to a 20-year long-term study, vaccine strains are the most critical factor influencing primary and secondary vaccine failure in post-transplant live-attenuated vaccination.

Liver transplantation (LT) recipients are susceptible to infections, including measles. Concerns about the safety and efficacy of live-attenuated vaccines, such as the measles-mumps-rubella (MMR) vaccine, have led to hesitancy among providers in administering them to immunocompromised patients. This 9-year interventional study assessed seroprotection against measles following MMR vaccination in pediatric LT recipients. Of 119 participants enrolled, 60 (50%) were seroprotected against measles after transplantation. Among the 59 nonseroprotected participants, 56 fulfilled safety criteria and received MMR vaccination with a seroprotection rate of 90% (95% confidence interval [CI], 73%-98%) after a first dose, 95% (95% CI, 85%-99%) after primary vaccination with 1 to 3 doses, comparable to nonimmunocompromized populations. However, measles antibodies declined over time, suggesting the need for regular monitoring, and booster doses. Half of the vaccinees (26/53, 49%) subsequently lost seroprotection. Among them, 23 received additional doses of MMR, with a high seroconversion rate. At their last follow-up (median, 6.1 years; interquartile range, 3.0-8.1 after inclusion), 63% (95% CI, 49%-75%) of all vaccinees were seroprotected against measles. In conclusion, MMR vaccination in pediatric LT recipients offers seroprotection against measles, but long-term immunity should be monitored closely.

This retrospective study aimed to investigate the response to hepatitis A virus (HAV) immunization following liver transplantation. We analyzed 234 vaccination records of 284 children who underwent liver transplantation between January 2003 and July 2021, including annual serologic results. Of the 120 HAV-naïve patients, approximately 71% and 83% showed seroconversion after receiving 1 and 2 vaccine doses, respectively. The third dose increased the seroconversion rate to 93%. In multivariable logistic regression analysis, the number of vaccine doses and age at first vaccine dose were independently associated with seroconversion. In contrast, additional immunosuppression with mycophenolate mofetil was negatively associated with seroconversion. In Cox regression analysis, of all 96 seroconverted children, younger age at first vaccination and additional immunosuppression with either mycophenolate mofetil or prednisolone were identified as independent risk factors for the early loss of HAV immunity. In summary, HAV immunization with the 3-dose vaccination series is recommended for pediatric liver transplant recipients. Antibody testing and booster vaccinations, if necessary, are recommended, especially for those living in endemic areas or with additional immunosuppressive treatments.

Solid organ transplant recipients face unique challenges in managing their immunosuppressed status, making vaccination a critical consideration. This review aimed to comprehensively analyze current recommendations, evaluate the efficacy of vaccinations in this population, and assess safety concerns. We explored the latest evidence on vaccine types, timing, and potential benefits for transplant patients, highlighting the importance of individualized approaches for routinely used vaccines as well as coronavirus disease 2019 vaccines. By synthesizing available data, this review underscored the pressing need to optimize vaccination strategies, ensuring that transplant recipients can obtain the full protection against many pathogens while minimizing risks associated with their post-transplant immunosuppression.

The European Union encompasses 30 outermost and overseas countries and territories (OCTs). Despite a recent increasing activity of renal transplantation in these territories, many patients still undergo transplantation in continental Europe, with follow-up care coordinated between health professionals from both their transplant center and their home region. Each territory has its unique infectious epidemiology which must be known to ensure appropriate care for kidney transplant recipients (KTRs).

This paper proposes a pragmatic approach to optimize pre-transplant check-up and to provide an overview of the specific epidemiological features of each region. It offers practical algorithms to help practitioners in managing infected KTR living in these territories. This work advocates for increased collaborative research among European OCTs.

Vaccinating pediatric solid organ transplant candidates against measles and varicella is crucial due to the risk of severe disease in immunosuppressed recipients and general avoidance of live virus vaccines post-transplantation. The world saw a resurgence of measles starting 2012 prompting the American Society of Transplantation in 2015 to release guidelines on recognition, prevention, and post-exposure prophylaxis of this disease in solid transplant recipients. This study aims to assess the extent of incomplete immunity to these viruses in candidates and the approach to immunity optimization during a period of heightened awareness.

A cross-sectional study from 2012 to 2016 at Cleveland Clinic Children's included pediatric solid organ transplant candidates. Data on vaccination history, serology, and demographics were collected. Incomplete immunity was defined by incomplete vaccination or seronegativity.

Among 91 candidates, 54.9% had complete varicella vaccination. Serological varicella immunity among patients tested varied by age: < 7 years, 50.0% positive in patients with complete schedules, none in the incomplete; ≥ 7 years, 50.0% positive in patients with complete schedules, 65.5% in the incomplete. For measles, 69.2% had complete vaccination, with immunity varying by age among those tested: < 7 years, 84.6% positive in patients with complete schedules, 42.9% in the incomplete; ≥ 7 years, 81.0% with complete, 62.5% with incomplete. Only 31.1% of those who qualified for a varicella additional dose and 28% who qualified for an additional measles dose received it, respectively.

Incomplete immunity to varicella and measles was prevalent in pediatric solid organ transplant candidates at our center during the study period. Despite an increase in global measles activity, our efforts to optimize immunity through additional vaccine doses were only partially successful. Future research should focus on addressing strategies and understanding barriers to ensure timely vaccination for this vulnerable population prior to transplant, especially during periods of increased viral activity.

Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pigs. PERV-A, PERV-B and PERV-C can be released as infectious virus particles and PERV-A and PERV-B can infect human cells in culture. PERV-C does not infect human cells, but high-titer recombinant PERV-A/C can infect them. Retroviruses are able to induce immunosuppression and/or tumors in the infected host. Numerous methods have been developed to study PERV in donor pigs. No PERV infections were observed in infection experiments as well as in preclinical and clinical xenotransplantation trials. Despite this, several strategies have been developed to prevent PERV infection of the recipient. PCR-based and immunological methods are required to screen xenotransplant recipients. Since the proviruses are integrated into the pig genome, PERV infection has to be distinguished from microchimerism, e.g., the presence of pig cells in the recipient, which is common in xenotransplantation. Sensitive PCR methods using pig short interspersed nuclear elements (SINE) sequences allow to detect pig cells easily. Virus infection can also be detected by an increase of viral genomic or mRNA in human cells. The method of choice, however, is to screen for specific antibodies against PERV using different recombinant PERV proteins, purified viruses or peptides.

Expected and unexpected donor-derived infections are a rare complication of solid organ transplantation, but can result in significant morbidity and mortality. Over the last years, the growing gap existing between patients on the waiting list and available organs has favored the use of organs from donors with suspected or confirmed infections, thanks to the improvement of risk mitigation strategies against transmission of well recognized and emerging infections. Given the recent developments, the particular interest of this review is to summarize data on how to maximize utilization of HIV+ donors in HIV+ recipients, the use of HCV-viremic donors and HBV positive donors. This article also covers the implications for recipient of organs from donors with bacteremia and the challenge of multidrug resistant (MDR) infections. Lastly this review describes emerging risks associated with recent Coronavirus Disease-2019 (COVID-19) pandemics.

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

This technical report accompanies the recommendations of the American Academy of Pediatrics for the routine use of influenza vaccine and antiviral medications in the prevention and treatment of influenza in children during the 2024 to 2025 season. The rationale for the American Academy of Pediatrics recommendation for annual influenza vaccination of all children without medical contraindications starting at 6 months of age is provided. Influenza vaccination is an important strategy for protecting children and the broader community against influenza. This technical report summarizes recent influenza seasons, morbidity and mortality in children, vaccine effectiveness, and vaccination coverage and provides detailed guidance on vaccine storage, administration, and implementation. The report also provides a brief background on inactivated (nonlive) and live attenuated influenza vaccines, available vaccines for the 2024-2025 influenza season, vaccination during pregnancy and breastfeeding, diagnostic testing for influenza, and antiviral medications for treatment and chemoprophylaxis. Strategies to promote vaccine uptake are emphasized.

The hepatitis A virus (HAV) vaccine is highly immunogenic in general, yet data on its use in liver-transplanted (LT) children is limited. This study aimed to determine the seroimmunity to HAV in all LT children, and the immunogenicity of an inactivated HAV vaccine in seronegative LT children at King Chulalongkorn Memorial Hospital. Seronegative LT children received the inactivated HAV vaccine at 0 and 6-8 months with adverse events monitored for 3 days post-immunization. The result reviewed that among 105 LT children, vaccination records were available for 81%, of which 7.1% and 16.5% with one and two doses of HAV vaccine were immunized before transplantation, respectively. Post-transplantation, 20.1% were seropositive for HAV, with 9.5% due to pre-transplant immunization. Eighty-three seronegative LT children (aged 7.25 ± 4.40 years; 48.6% male) received two vaccine doses. The seropositive rate increased following the first and second doses and reached to 51.5%, and 92.9%, respectively (p < 0.001), with no serious adverse events reported. Age at vaccination and the interval from transplantation to vaccination were risk factors for non-responsiveness (p < 0.001). The study highlighted inadequate HAV vaccination coverage, leaving most LT children susceptible to infection. HAV vaccine proved highly immunogenic and safe, emphasizing the need for improved vaccination strategies before and after liver transplantation.Trial registration TCTR20220110001.

Vaccination before solid organ transplantation is recommended since post-transplantation immunosuppression is known to impair vaccine responses. However, little is known about post-transplantation seroprotection rates in organ transplant recipients vaccinated pre-transplantation. We aimed to investigate the proportion of transplant recipients vaccinated against hepatitis B virus (HBV) and invasive pneumococcal disease (IPD) pre-transplantation at the time of listing for transplantation with post-transplantation seroprotection. We included 136 solid organ transplant (SOT) recipients vaccinated at the time of listing for transplantation. We investigated post-transplantation antibody concentrations against HBV and IPD. Established antibody thresholds were used to define seroprotection. The proportions of SOT recipients with post-transplantation seroprotection were 27.9% (n = 38) and 42.6% (n = 58) against HBV and IPD, respectively. Compared to completing HBV vaccination pre-transplantation, completing post-transplantation vaccination (adjusted odds ratio (aOR): 7.8, 95% CI: 2.5-24.5, p < 0.001) and incomplete vaccination (aOR: 6.3, 95% CI: 1.2-32.6, p = 0.028) were associated with non-response against HBV, after adjustment for confounders. Importantly, patients with seroprotection at the time of listing had lower odds of non-response against HBV (aOR: 0.04, 95% CI: 0.0-0.1, p < 0.001) and IPD (aOR: 0.3, 95% CI: 0.1-0.7, p = 0.007) compared to those without seroprotection. SOT recipients vaccinated pre-transplantation had low post-transplantation seroprotection rates against HBV and IPD. However, SOT recipients with seroprotection at the time of listing had lower odds of non-response, suggesting early vaccination should be a priority.

Hepatitis B virus (HBV) vaccination is recommended for solid organ transplant (SOT) candidates. However, there is a lack of data on the HBV vaccine compliance, serologic response, and durability of HBV seroprotection in thoracic organ transplantation recipients.

We conducted a retrospective study of adult thoracic organ (heart and lung) transplant candidates who received HBV vaccination at Mayo Clinic sites in Minnesota, Arizona, and Florida between January 2018 and August 2023. Conventional recombinant hepatitis B vaccine (Recombivax HB) was used before 2020, and Heplisav-B was preferred after 2020. HBV seroprotection was defined as hepatitis B surface antibody (HBsAb) ≥ 10 IU/L. Furthermore, we compared characteristics between recipients who maintained HBV seroprotection and those who lost HBV seroprotection (HBsAb < 10 IU/L) at 30 days posttransplantation (D30).

Among 922 candidates who were eligible for HBV vaccination, 430 (47%) completed the HBV vaccine series. Patients receiving Heplisav-B were more likely to complete the series than Recombivax HB (81% vs. 60%, p < 0.001) and Heplisav-B had a higher seroprotection rate than Recombivax HB (75% vs. 64%, p = 0.023). Multivariate logistic regression analysis identified receiving Heplisav-B as an independent predictor for HBV seroprotection (adjusted odds ratio [aOR] 1.723; 95% confidence interval [CI] 1.056-2.810; p = 0.029). A total of 145 thoracic organ transplant recipients achieved HBV seroprotection at the date of transplantation. Loss of HBV seroprotection occurred in 38 (26%) patients at D30. Multivariate logistic regression analysis identified two predictors for HBV seroprotection loss at D30: age ≥ 60 years (aOR, 2.503; 95% CI 1.026-6.107; p = 0.044), and pretransplant HBsAb level between 10 and 100 IU/L (aOR, 18.575; 95% CI 5.211-66.209; p < 0.001).

Although less than half of thoracic organ transplant candidates completed HBV vaccine series pretransplant, Heplisav-B provided a higher vaccine completion rate and seroprotection than the 3-dose Recombivax HB. Clinicians should also be aware of the increased loss of HBV seroprotection in thoracic organ transplant recipients with age ≥ 60 years and pretransplant HBsAb between 10 and 100 IU/L. Assessment of seroprotection after HBV vaccination should be prioritized during the pretransplant period.

Since their conception with the smallpox vaccine, vaccines used worldwide have mitigated multiple pandemics, including the recent COVID-19 outbreak. Insightful studies have uncovered the complexities of different functional networks of CD4 T cells (T helper 1 (Th1); Th2, Th17) and CD8 T cells (T cytotoxic; Tc), as well as B cell (BIgM, BIgG, BIgA and BIgE) subsets, during the response to vaccination. Both T and B cell subsets form central, peripheral, and tissue-resident subsets during vaccination. It has also become apparent that each vaccination forms a network of T regulatory subsets, namely CD4+ CD25+ Foxp3+ T regulatory (Treg) cells and interleukin-10 (IL-10)-producing CD4+ Foxp3- T regulatory 1 (Tr1), as well as many others, which shape the quality/quantity of vaccine-specific IgM, IgG, and IgA antibody production. These components are especially critical for immunocompromised patients, such as older individuals and allograft recipients, as their vaccination may be ineffective or less effective. This review focuses on considering how the pre- and post-vaccination Treg/Tr1 levels influence the vaccination efficacy. Experimental and clinical work has revealed that Treg/Tr1 involvement evokes different immune mechanisms in diminishing vaccine-induced cellular/humoral responses. Alternative steps may be considered to improve the vaccination response, such as increasing the dose, changing the delivery route, and/or repeated booster doses of vaccines. Vaccination may be combined with anti-CD25 (IL-2Rα chain) or anti-programmed cell death protein 1 (PD-1) monoclonal antibodies (mAb) to decrease the Tregs and boost the T/B cell immune response. All of these data and strategies for immunizations are presented and discussed, aiming to improve the efficacy of vaccination in humans and especially in immunocompromised and older individuals, as well as organ transplant patients.

Solid organ transplant (SOT) candidates and recipients are a fragile population, in which the presence of a pre-transplant disease leading to organ insufficiency and the post-transplant immunosuppressive treatment expose them to an increased risk of infectious diseases. The best intervention to guarantee efficient prevention of infections, with optimal cost-benefit ratio, is represented by vaccination programs; however, the response to vaccines needs that the immune system maintains a good function. This is even more relevant at paediatric age, when specific immunological conditions make transplant candidates and recipients particularly vulnerable. Paediatric patients may be naïve to most infections and may have incomplete immunization status at the time of transplant listing due to their age. Moreover, the unaccomplished development of a mature immune system and the immunosuppressive regimen adopted after transplant might affect the efficacy of post-transplant vaccinations. Therefore, every effort should be made to obtain the widest vaccination coverage before the transplantation, whenever possible. This review reports the most relevant literature, providing information on the current approach to the vaccinations in paediatric SOT candidates and recipients.

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Health care transition (HCT) is the process of changing from a pediatric to an adult model of care. Young adult pediatric recipients of liver transplant transferring from pediatric to adult health care services are highly vulnerable and subject to poor long-term outcomes. Barriers to successful transition are multifaceted. A comprehensive HCT program should be initiated early in pediatrics and continued throughout young adulthood, even after transfer of care has been completed. It is critical that pediatric and adult liver transplant providers establish a partnership to optimize care for these patients. Adult providers must recognize the importance of HCT and the need to continue the transition process following transfer. While this continued focus on HCT is essential, current literature has primarily offered guidance for pediatric providers. This position paper outlines a framework with a sample set of tools for the implementation of a standardized, multidisciplinary approach to HCT for adult transplant providers utilizing "The Six Core Elements of HCT." To implement more effective strategies and work to improve long-term outcomes for young adult patients undergoing liver transplant, HCT must be mandated as a routine part of posttransplant care. Increased advocacy efforts with the additional backing and support of governing organizations are required to help facilitate these practices.

Immune-mediated renal diseases are a diverse group of disorders caused by antibody, complement, or cell-mediated autosensitization. Although these diseases predispose to infection on their own, a growing array of traditional and newer, more targeted immunosuppressant medications are used to treat these diseases. By understanding their mechanisms of action and the infections associated with suppression of each arm of the immune system, nephrologists can better anticipate these risks and effectively prevent and recognize opportunistic infections. Focusing specifically on nonkidney transplant recipients, this review discusses the infections that can be associated with each of the commonly used immunosuppressants by nephrologists and suggest interventions to prevent infectious complications in patients with immune-mediated renal disease.

Transplant infectious disease (TID) clinicians are integral to the pre-transplantation evaluation. Pre-transplant evaluations allow clinicians to assess risk factors for latent infections and relevant exposures to potential pathogens, address immunizations, and optimize patients' health and understanding of life after transplant. However, there is not a standardized approach to the pre-transplant evaluation. This article reviews the details of performing successful pre-transplant evaluations, including updated recommendations on available vaccines and contemporary opinions on marijuana use. This resource can be used for teaching with trainees or for early career TID clinicians.

Solid organ transplantation recipients have an increased risk of infection, exacerbated by immunosuppressant medications that need to finely balance suppression of the immune system to prevent allograft rejection while avoiding over-suppression leading to infections and malignancy. Exercise modulates immune functions, with moderate-intensity activities particularly associated with enhanced antiviral immunity and reduced infection incidence. However, investigations of the effects of exercise and physical activity on immune function and infection risk posttransplantation are scarce. This review highlights areas where the relationship between exercise, immune function and infection risk has greatest potential for benefit for solid organ transplantation and therefore greatest need for investigation.

Moderate and higher intensity exercise do not appear to cause adverse immunological effects in kidney transplantation recipients, although evidence from other organ transplantation is lacking. Evidence from healthy younger and older adults suggests that regular exercise can reduce risk of respiratory infections and latent herpesvirus reactivation and improves antibody responses to vaccination, which is of great importance for organ transplantation recipients.

There is a strong need for research to investigate the role of exercise on immune function and infection risk in solid organ transplantation to improve both allograft survival and long-term health of the recipient.

Administration of live vaccines following liver transplant (LT) has historically not been recommended due to concerns regarding risk of vaccine-attenuated disease. However, there is evidence suggesting that in select transplant recipients live vaccinations can be administered safely. Studies in other regions have indicated that despite this evidence many clinicians remain hesitant to administer live vaccinations.

A REDCap survey was distributed to gastroenterologists, pediatricians, and infectious diseases physicians at pediatric centers across Australia and New Zealand via email between September and November 2023. The survey included a series of questions regarding live vaccine and varicella postexposure prophylaxis (PEP) practices in pediatric LT recipients and barriers to live vaccine administration in this cohort.

There was a total of 16 responses to the survey, from 10 different pediatric centers, including 10/11 pediatric gastroenterology centers and all four pediatric LT centers in the region. Only 31% (5/16) of respondents (from 3/10 different centers) offer live vaccines. The main barrier to live vaccine administration was clinician reluctance and the main reason for not offering live vaccines was insufficient safety data. Sixty-nine percent (11/16) of respondents take vaccination status and/or serology into account when deciding whether to offer varicella PEP to this cohort. Respondents universally offer varicella zoster immunoglobulin as PEP, though 31% (5/16) also offer antiviral medication.

Many clinicians in our region remain hesitant to provide live vaccines to pediatric LT recipients, with concerns regarding insufficient safety data. Updated local guidelines may help to address this.

Varicella-zoster virus (VZV) pretransplant immunization rates, exposures, and posttransplant disease are poorly characterized among pediatric solid organ transplant (SOT) recipients in the two-dose varicella vaccine era.

A retrospective analysis of the electronic health records among children <18 years old who received SOT from January 1, 2011 through December 31, 2021, was performed at a single center to assess for missed pretransplant varicella vaccination opportunities, characterize VZV exposures, and describe posttransplant disease.

Among 525 children, 444 were ≥6 months old (m.o.) at SOT with a documented VZV vaccine status. Eighty-five (19%) did not receive VZV Dose One; 30 out of 85 (35%) could have been immunized. Infants 6-11 m.o. accounted for 14 out of 30 (47%) missed opportunities. Among children ≥12 m.o. with documented Dose Two status (n = 383), 72 had missed vaccination opportunities; 57 out of 72 (79%) were children 1-4 years old. Most children had unclassifiable pre-SOT serostatus as varicella serology was either not obtained/documented (n = 171) or the possibility of passive antibodies was not excluded (n = 137). Of those with classified serology (n = 188), 69 were seroimmune. Forty-seven of 525 (9%) children had recorded VZV exposures; two developed varicella-neither had documented pre-SOT seroimmunity nor had received post-exposure prophylaxis. Nine additional children had medically attended disease: four primary varicella and five zoster. Of the 11 cases, 10 had cutaneous lesions without invasive disease; one had multi-dermatomal zoster with transaminitis. Seven (64%) received treatment exclusively outpatient.

VZV exposure and disease still occur. Optimizing immunization among eligible candidates and ensuring patients have a defined VZV serostatus pretransplantation remain goals of care.

Lung transplant patients are more likely to develop severe coronavirus disease 2019 (COVID-19) compared with the general population and should be vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, previous studies have reported reduced vaccination immunogenicity in lung transplantation patients. We aimed to investigate the serological response and associated factors after SARS-CoV-2 vaccination in this population. Lung transplant patients without a history of contracting coronavirus disease who had received a second or higher dose of SARS-CoV-2 vaccination were enrolled. The anti-SARS-Cov-2 spike and neutralizing antibody levels were measured in blood samples. Firth's logistic regression analysis was performed to assess the factors associated with non-response after vaccination. Forty-six lung transplant patients were enrolled, of which sixteen (34.8%) showed a serological response to vaccination. All patients who received anti-SARS-CoV-2 vaccination before transplantation (n = 5) exhibited a serological response. No significant difference was observed in anti-SARS-CoV-2 S antibody or neutralization titers based on the number and timing of vaccination. Firth's logistic regression showed an association between lower hemoglobin levels (odds ratio, 0.59; confidence interval, 0.35-0.92; p = 0.017) and non-response to SARS-CoV-2 vaccination. Lung transplant patients showed poor serologic responses after SARS-CoV-2 vaccination in this pilot study; anemia may be associated with this poor response.

Infection management in solid organ transplantation poses unique challenges, with a diverse array of potential pathogens and associated antimicrobial therapies. With limited high-quality randomized clinical trials to direct optimal care, therapeutic "myths" may propagate and contribute to suboptimal or excessive antimicrobial use. We discuss 6 therapeutic myths with particular relevance to solid organ transplantation and provide recommendations for infectious diseases clinicians involved in the care of this high-risk population.