Immunization after renal transplantation: current clinical practice

Dutch Healthcare Professionals' Opinion on the Allocation of Responsibilities concerning Prescribing and Administering Medically Indicated Vaccines to Immunocompromised Patients

BACKGROUND

Specific vaccines are indicated for immunocompromised patients (ICPs) due to their vulnerability to infections. Recommendation of these vaccines by healthcare professionals (HCPs) is a crucial facilitator for vaccine uptake. Unfortunately, the responsibilities to recommend and administer these vaccines are not clearly allocated among HCPs involved in the care of adult ICPs. We aimed to evaluate HCPs' opinions on directorship and their role in facilitating the uptake of medically indicated vaccines as a basis to improve vaccination practices.

METHODS

A cross-sectional survey was performed among in-hospital medical specialists (MSs), general practitioners (GPs), and public health specialists (PHSs) in the Netherlands to assess their opinion on directorship and the implementation of vaccination care. Additionally, perceived barriers, facilitators, and possible solutions to improve vaccine uptake were investigated.

RESULTS

In total, 306 HCPs completed the survey. HCPs almost unanimously (98%) reported that according to them, the primary treating physician is responsible for recommending medically indicated vaccines. Administering these vaccines was seen as a more shared responsibility. The most important barriers experienced by HCPs in recommending and administering were reimbursement problems, a lack of a national vaccination registration system, insufficient collaboration among HCPs, and logistical problems. MSs, GPs and PHSs all mentioned the same three solutions as important strategies to improve vaccination practices, i.e., reimbursement of vaccines, reliable and easily accessible registration of received vaccines, and arrangements for collaboration among the different HCPs that are involved in care.

CONCLUSION

The improvement in vaccination practices in ICPs should focus on better collaboration among MSs, GPs, and PHSs, who should know each other's expertise; clear agreement on responsibility; reimbursement for vaccines; and the availability of clear registration of vaccination history.

Review of Influenza Virus Vaccines: The Qualitative Nature of Immune Responses to Infection and Vaccination Is a Critical Consideration

Influenza viruses have affected the world for over a century, causing multiple pandemics. Throughout the years, many prophylactic vaccines have been developed for influenza; however, these viruses are still a global issue and take many lives. In this paper, we review influenza viruses, associated immunological mechanisms, current influenza vaccine platforms, and influenza infection, in the context of immunocompromised populations. This review focuses on the qualitative nature of immune responses against influenza viruses, with an emphasis on trained immunity and an assessment of the characteristics of the host–pathogen that compromise the effectiveness of immunization. We also highlight innovative immunological concepts that are important considerations for the development of the next generation of vaccines against influenza viruses.

The effect of universal infant vaccination on the prevalence of hepatitis B immunity in adult solid organ transplant candidates

BACKGROUND

Hepatitis B virus (HBV) immunity is recommended to optimize outcomes after solid organ transplantation (SOT). This study assessed the prevalence and predictors of HBV immunity at the time patients were placed on transplant waiting list over a period from 1997 to 2019 in a low HBV endemic region.

METHODS

Data were obtained from the University Hospitals Leuven transplant database. Minors and patients with past/current HBV infection were excluded. From 1986, Belgian patients are covered by the universal infant vaccination; therefore, birth cohort was stratified in those born ≥1986 vs <1986.

RESULTS

The study population consisted of 3297 SOT candidates. HBV immunity rate was superior in renal transplant candidates (55.3%), and this number was 21.5%, 15.4% and 16.8% for liver, cardiac and pulmonary transplant candidates, respectively, P < .001. Among liver transplant candidates, HBV immunity rate was 14.8% in decompensated cirrhotic patients and 27.9% in those without advanced cirrhosis (P < .001). The overall immunity rate increased from 19.3% in period 1997-2008 to 32.8% in 2009-2019, P < .001. In multivariable analyses, younger age (odds ratio (OR) 95% confidence interval (CI): 0.97-0.98, P < .001) and birth cohort ≥ 1986 (OR 95% CI: 1.18-2.66, P = .006) were associated with increased HBV immunity.

CONCLUSION

An increase in HBV immunity was observed over a 20-year period related to the introduction of universal infant HBV vaccination. Nevertheless, this study highlights the low overall HBV immunity at the time of listing for organ transplantation and points out the need of an increased awareness and vaccination strategy at an early disease stage.

Determinants of Vaccination Uptake in Risk Populations: A Comprehensive Literature Review

Vaccination uptake has decreased globally in recent years, with a subsequent rise of vaccine-preventable diseases. Travellers, immunocompromised patients (ICP), and healthcare workers (HCW) are groups at increased risk for (severe) infectious diseases due to their behaviour, health, or occupation, respectively. While targeted vaccination guidelines are available, vaccination uptake seems low. In this review, we give a comprehensive overview of determinants-based on the integrated change model-predicting vaccination uptake in these groups. In travellers, low perceived risk of infection and low awareness of vaccination recommendations contributed to low uptake. Additionally, ICP were often unaware of the recommended vaccinations. A physician's recommendation is strongly correlated with higher uptake. Furthermore, ICP appeared to be mainly concerned about the risks of vaccination and fear of deterioration of their underlying disease. For HCW, perceived risk of (the severity of) infection for themselves and for their patients together with perceived benefits of vaccination contribute most to their vaccination behaviour. As the determinants that affect uptake are numerous and diverse, we argue that future studies and interventions should be based on multifactorial health behaviour models, especially for travellers and ICP as only a limited number of such studies is available yet.

Vaccination in adult liver transplantation candidates and recipients

In patients with chronic liver disease and liver transplant recipients, cirrhosis-associated immune dysfunction syndrome and immunosuppressant drug regimens required to prevent graft rejection lead to a high risk of severe infections, associated with acute liver decompensation, graft loss and increased mortality. In addition to maintain their global health status, vaccination represents a major preventive measure against specific infectious risks of particular concern in this population, such as invasive pneumococcal diseases, influenza or viral hepatitis A and B. However, immunization in this setting raises several issues: i) recommended vaccination schedules rely on sparse immunogenicity data without clinical efficacy and effectiveness trials designed for this specific population; ii) dynamics of immunosuppression makes timing of immunization challenging; iii) live attenuated vaccines are contraindicated after transplantation; and iv) vaccines tolerance is poorly known in cirrhotic patients. This review outlines the rational for vaccination in adult liver transplant candidates and recipients and available data regarding immunization in this specific population.

Comparison of the immunogenicity of Dukoral® oral cholera vaccine between renal transplant recipients on either a calcineurin inhibitor or mycophenolate - A controlled trial

BACKGROUND

The evidence for recommendations regarding vaccination in solid organ transplant recipients is sparse. There is little data comparing vaccine responses between groups on different immunosuppressive drugs. This study was conducted to evaluate the antibody response to Dukoral® oral cholera vaccine in renal transplant recipients (RTR).

METHODS

In a single-center non-randomized controlled clinical trial, healthy volunteers (n = 21) and renal transplant recipients (n = 30) were vaccinated with the oral whole cell/recombinant B subunit cholera vaccine Dukoral® (Valneva Inc., Vienna, Austria). The RTR were stratified according to their maintenance immunosuppressive therapy: either prednisone and a calcineurin inhibitor (cyclosporine A or tacrolimus; P/CNI group; n = 15) or prednisone and mycophenolate (P/MMF group; n = 15). All volunteers ingested Dukoral® at baseline and at day 14. Serum samples were drawn at day 0 and day 21. The primary outcome was seroconversion, defined as either a 3-fold IgA serum titer increase in anti-cholera toxin B antibodies and/or a 4-fold rise in the serum vibriocidal titer.

RESULTS

Follow-up was complete. Seroconversion after vaccination was 57% (standard error, SE 9%) in RTR and 81% (SE 9%) in healthy controls (Relative Risk, RR 0.70; 95% CI 0.48-1.02). When stratified according to maintenance immunosuppression, the seroconversion rate was 67% (SE 12%) in the P/CNI group (RR compared with controls 0.82; 95% CI 0.55-1.25) and 47% (SE 13%) in the P/MMF group (RR compared with controls 0.58; 95% CI 0.32-1.03).

CONCLUSION

Adverse events were mild to moderate and transient. The response to Dukoral was weaker and the seroconversion rate was lower in renal transplant recipients than in healthy controls. In particular, those using mycophenolate had a poor response. Nevertheless, more than half of the transplant recipients seroconverted. Therefore oral vaccines should not be discarded as a potential tool for protection of solid organ transplant recipients. This trial is registered in clinicaltrials.gov under NCT01109914.

Vaccinations in pediatric kidney transplant recipients

Pediatric kidney transplant (KT) candidates should be fully immunized according to routine childhood schedules using age-appropriate guidelines. Unfortunately, vaccination rates in KT candidates remain suboptimal. With the exception of influenza vaccine, vaccination after transplantation should be delayed 3-6 months to maximize immunogenicity. While most vaccinations in the KT recipient are administered by primary care physicians, there are specific schedule alterations in the cases of influenza, hepatitis B, pneumococcal, and meningococcal vaccinations; consequently, these vaccines are usually administered by transplant physicians. This article will focus on those deviations from the normal vaccine schedule important in the care of pediatric KT recipients. The article will also review human papillomavirus vaccine due to its special importance in cancer prevention. Live vaccines are generally contraindicated in KT recipients. However, we present a brief review of live vaccines in organ transplant recipients, as there is evidence that certain live virus vaccines may be safe and effective in select groups. Lastly, we review vaccination of pediatric KT recipients prior to international travel.

Immunogenicity and safety of double versus standard dose of the seasonal influenza vaccine in solid-organ transplant recipients: A randomized controlled trial

BACKGROUND

The use of vaccines with higher doses of antigen is an attractive strategy to improve the immunogenicity of influenza vaccination in transplant recipients. However, the effect of vaccination with a double-dose (DD) containing 30 µg of antigen in this population remains unknown.

METHODS

We performed a randomized controlled trial to compare the immunogenicity and safety of DD (30 µg) vs. standard dose (SD, 15 µg) of a trivalent inactivated influenza vaccine in kidney and liver transplant recipients. Immunogenicity was assessed by hemagglutination-inhibition assay. Vaccine response was defined as seroconversion to at least one viral strain 2 weeks after vaccination and seroprotection as a titer ≥40.

RESULTS

Sixty-three kidney and 16 liver transplant recipients were enrolled. Forty patients received the DD and 39 the SD vaccine. Overall, 40% of patients in the DD compared to 26% in the SD group (P = 0.174) responded to vaccine. In the DD arm, more patients were seroprotected to all viral strains after vaccination (88% vs 69%, P = 0.048). Post vaccination geometric mean titers of antibodies were 131.9 vs. 89.7 (P = 0.187) for H1N1, 185.4 vs. 138.7 (P = 0.182) for H3N2, and 96.6 vs. 68.8 (P = 0.081) for influenza B with the DD vs. SD. In both groups, most of the adverse events were mild and no vaccine-related severe adverse events were observed.

CONCLUSION

Double-dose influenza vaccine is safe and may increase antibody response in transplant recipients. In this population, DD vaccination could be an alternative when high-dose vaccine is not available. NCT02746783.

Immunization in end stage renal disease: The perception of waiting list patients

BACKGROUND

The number of patients with chronic kidney disease is increasing worldwide, as well as the number of patients in kidney transplant waiting lists. In order to prevent infections related to immunosuppressive therapy, immunization guidelines for CKD patients before transplantation have been proposed. The aim of the present study was to evaluate adherence to immunization in a cohort of CKD patients in transplant waiting list and their renal replacement therapy clinics.

METHODS

CKD patients older than 18 years old, receiving renal replacement therapy longer than 12 months and included in kidney transplant waiting list at University of Campinas (Unicamp) were enrolled.

RESULTS

From February 2014 to December 2015, 105 patients fulfilled the inclusion criteria. Complete hepatitis B vaccination was observed in 73% and influenza vaccine in 67%. None of the other vaccine protocols reached 50% of coverage. Patients receiving immunization at primary health units presented higher coverage for diphtheria, tetanus (dT), measles, mumps, rubella (MMR), and hepatitis B vaccines, while patients immunized at renal replacement therapy clinics showed higher prevalence of pneumococcus (pneumo23).

CONCLUSION

The low rates of immunization could reflect the RRT's clinics knowledge about the vaccines guidelines and its application on daily care. We suggest an integration between transplant center and RRT clinics, through lectures, periodic checking of vaccination cards, and easy to follow guidelines in order to provide a better vaccine coverage and to obtain higher immunization rates.

Low rates of vaccination in listed kidney transplant candidates

Despite clear consensus and strong recommendations, vaccination rates of kidney transplant (KT) recipients have remained below targets. As vaccination is most effective if it is given prior to transplantation and the initiation of immunosuppression, patients should ideally have their vaccination status assessed and optimized in the pre-transplant period. We performed a retrospective chart review to characterize vaccination rates and factors associated with gaps in vaccination in a single-center population of waitlisted patients being evaluated for kidney transplantation. We evaluated 362 KT patients. Three-quarters were receiving dialysis at the time of evaluation. Immunization rates were low with 35.9% of patients having completed vaccination for Pneumococcus, 55% for influenza, 6.9% for zoster, and 2.5% for tetanus. On multivariable analysis, patients who received other vaccines, including influenza, tetanus, or zoster vaccine (odds ratio [OR] 10.55, 95% confidence interval [CI] 5.65-19.71) were more likely to receive pneumococcal vaccine. Blacks (OR 0.24, 95% CI 0.12-0.47) were less likely to receive pneumococcal vaccine compared to whites. Patients on dialysis, and those active on the waiting list were more likely to receive pneumococcal vaccine than other groups (OR 2.81, 95% CI 1.44-5.51, and OR 1.84, 95% CI 1.08-3.14, respectively). We found that the overall immunization rate against common vaccine-preventable infections was low among patients evaluated for kidney transplantation. A significant gap remains between recommendations and vaccine uptake in clinical practice among this high-risk population.