Vaccination against Hepatitis B in Patients with Chronic Liver Disease Awaiting Liver Transplantation

Vaccination in liver diseases and liver Transplantation: Recommendations, implications and opportunities in the post-covid era

The interest in vaccination efficacy and toxicity has surged following the Covid-19 pandemic. Immune responses to several vaccines have been shown to be suboptimal in patients with chronic liver disease (CLD) or post-liver transplant (LT), as a consequence of cirrhosis-associated immune dysfunction (CAID) or post-LT immunosuppression respectively. Accordingly, vaccine-preventable infections may be more common or severe than in the general population. The Covid-19 pandemic has greatly accelerated research and development into vaccination technology and platforms, which will have spillover benefits for liver patients. The aims of this review are: (i) to discuss the impact of vaccine-preventable infections on CLD and post-LT patients, (ii) to appraise current evidence supporting vaccination strategies, and (iii) to provide some insight into recent developments relevant for liver patients.

Efficacy of Hepatitis B Virus Vaccines HBVaxpro40© and Fendrix© in Patients with Chronic Liver Disease in Clinical Practice

Chronic liver disease results in a low response rate to the hepatitis B virus vaccine. Information on the efficacy of the double adjuvanted vaccine FENDRIX® (3-O-desacyl-4'-monophosphoryl lipid A and aluminum phosphate) and single adjuvant HBVAXPRO®40 (aluminum hydroxyphosphate sulfate) in chronic liver disease is scarce. The primary aim of this prospective study in clinical practice was to evaluate the effectiveness of HBVAXPRO®40 and FENDRIX® in this setting. Patients received HBVAXPRO® (0, 1 and 6 months) or FENDRIX® (0, 1, 2 and 6 months) depending on availability. Clinical data and anti-HBs levels were collected at 2, 6 and 12 months. A total of 125 patients were included (mean age 61.8 years; 57.6% males; 43.2% liver cirrhosis; 75.9% Child A and 24.1% Child B): 76 were vaccinated with HBVAXPRO® and 49 with FENDRIX®. There were no significant differences between the two vaccines. The overall response rates at 2, 6 and 12 months were 76.8, 72.8 and 59.2%, respectively. In the univariate analysis, active alcohol intake, alcohol etiology, liver cirrhosis and ultrasound signs of portal hypertension were associated with a lower response to vaccination, whereas in the multivariate analysis, liver cirrhosis was the only factor that significantly increased the likelihood of nonresponse (OR 10.5). HBVAXPRO® and FENDRIX® are good options for HBV vaccination in patients with chronic liver disease.

Efficacy of Hepatitis B Vaccine in Adults with Chronic Liver Disease

BACKGROUND & AIMS

Although HBV vaccine has a 95% seroconversion rate in the general population, patients with chronic liver disease have reduced seroconversion rates (16-79%). The aim of the study was to describe seroconversion rates with HBV vaccines in patients with chronic liver disease.

APPROACH & RESULTS

Retrospective chart review was performed among 652 patients who received a complete HBV vaccine series in the hepatology clinic. Of those, 126 patients that were included, 111 received a single dose series, and 15 patients received a double dose series. The seroconversion rate was overall low at 35%, and stayed the same at 35% with double dose and at 33% with single dose. Patients who received a single dose series were further analyzed to review risk factors for seroconversion. Overall, 65% of patients had cirrhosis. Patients were more likely to seroconvert if no cirrhosis (51% vs 72%, P=.04), higher aminotransferase levels, intermediate anti-HBs (2.5-11.9 mIU/mL) at baseline (87.5% vs 14%).

CONCLUSION

Patients with chronic liver disease had a low rate (35%) of response to HBV vaccination. The response rates did not improve in patients that received double dose series. Patients with cirrhosis, lower aminotransferase levels and with a lower baseline anti-HBs had decreased response rates.

Vaccination in Chronic Liver Disease: An Update

Patients with chronic liver disease (CLD) with or without cirrhosis remain at risk of developing hepatic decompensation when infected with viral or bacterial pathogens. The Advisory Committee on Immunization Practices (ACIP) currently recommends vaccination in CLD against hepatitis A virus (HAV), hepatitis B virus (HBV), influenza, pneumococcus, herpes zoster, tetanus, diphtheria, pertussis, and SARS-CoV-2. Inactivated vaccines are preferred over live attenuated ones, especially in transplant recipients where live vaccines are contraindicated. As the severity of the liver disease progresses, vaccine efficacy declines, and therefore, vaccines should be ideally administered early in the disease course for optimal immune response. Despite the strong recommendations, overall vaccination coverage in CLD remains poor; however, it is encouraging to note that in recent years coverage against influenza and pneumococcus has shown some improvement. Inadequate access to healthcare, lack of information on vaccine safety, poor financial reimbursement for healthcare providers, and vaccine misinformation are often responsible for low immunization rates. This review summarizes the impact of vaccine-preventable illness in those with CLD, updated vaccine guidelines, seroconversion rates in the vaccinated, and barriers faced by healthcare professionals in immunizing those with liver disease.

Hepatitis B vaccine coverage and risk factors for lack of vaccination in subjects with HBsAg negative liver cirrhosis in Italy: still, much work should be done

BACKGROUND

in Italy, Hepatitis-B-vaccine is advised and provided free-of-charge for subjects with chronic liver disease (CLD), including liver cirrhosis.

AIMS

to evaluate HB-vaccine-coverage and variables associated with lack of vaccination in cirrhotic patients with particular attention to cirrhosis' etiology.

METHODS

cirrhotic patients of any etiology (excluding HBsAg+) referring to 8 tertiary-centers were prospectively enrolled for a-six-months-period in 2019. Subjects were asked if they received HB-vaccine previously. Multiple-logistic-regression-analysis was performed to identify independent predictors of lack of vaccination.

RESULTS

731 cases were recruited. Overall-vaccine-coverage was 16.3% (23.7% in those younger than 65y, 10.0% in those older than 64y; p<0.001). Lack of information was the most frequent reason (78.5% of cases) reported by the 608 unvaccinated subjects, without statistical difference by area-of-birth (77.3% in Italians, 80.0% in people-born-abroad). Age>64 y (OR: 4.27; CI 95%: 2.52-7.24), educational level<9 years (OR: 3.52; CI 95%: 2.10-5.90), residence in South/Sardinia (OR 2.52; CI 95%:1.45-4.39), birth-abroad (OR 5.09; CI 95%: 1.07-24-.17), and Child grade B/C(OR 2.68; CI 95%: 1.35-5.33) all resulted independent predictors of likelihood of lack of vaccination.

CONCLUSIONS

Vaccination-rate in cirrhotic patients results very low. Vaccine-coverage implementation in these subjects, is warranted. Vaccine should be provided in early CLD, when immunization is most effective.

Efficacy of an accelerated double-dose hepatitis B vaccine regimen in patients with cirrhosis

The hepatitis B (HBV) vaccine is recommended in unvaccinated adults with cirrhosis, despite its low efficacy. We aimed to evaluate the response to a double-dose/accelerated vaccine schedule in patients with cirrhosis admitted into a hepatology ward. All patients with cirrhosis admitted to the hepatology ward without exclusion criteria were offered the HBV HBVAXPRO 40mcg vaccine at months 0, 1 and 2. Non-responders received a second cycle. We evaluated 468 patients and only 19% were seroprotected against HBV. In 196 patients without exclusion criteria for HBV vaccination, the per protocol response rate (anti-HBs >10 U/ml) was 23% after a first cycle and 59% after a second cycle. The overall response per intention to treat was only 23%. We have not identified predictors of response. Only one patient had a mild adverse event. Most patients with cirrhosis admitted in the hepatology ward are unprotected against HBV. Although a second HBV vaccination cycle increases the response rate, the poor overall response reinforces the implementation of HBV vaccination before the development of cirrhosis.

The role of hepatitis B vaccine challenge dose in patients with underlying health conditions

We have evaluated the immunological response to Hepatitis B virus (HBV) booster vaccine dose in 129 adults with underlying diseases in comparison with 694 subjects at occupational risk of infection, who have previously completed the primary series and resulted with anti-HBs <10 mIU/mL. After booster dose, 60.5% of the patients with underlying diseases and 14.8% of the subjects at occupational risk resulted seronegative. By comparing two groups, rate of subjects with anamnestic response was higher in at occupational risk group respect to that at risk for medical conditions (OR: 5.99 [95%IC, 3.81-9.41], p < .001). This difference was associated to gender (males/females: OR: 0.619 [95%IC, 0.421-0.910], p = .015) and age (better response for younger people, p = .011).

Infections in Cirrhosis

Purpose of review

Patients with cirrhosis are at high risk of developing serious infections. Bacterial infections remain the most common cause of morbidity and mortality in these patients. This review is focused on the prevalence of infections in those with cirrhosis, including multidrug-resistant (MDR) pathogens, pathogenesis of infection-related acute-on-chronic liver failure (ACLF), current treatment recommendations, and prophylactic strategies in patients with cirrhosis.

Recent findings

Recent epidemiological studies have noted an emerging prevalence of MDR bacterial infections and associated with poor prognosis, and a high rate of treatment failure and mortality. Therefore, new recommendations on empirical antibiotic use based on epidemiological data have been developed in order to improve outcomes.

Summary

Spontaneous bacterial peritonitis (SBP) and urinary tract infection (UTI) are the most frequent infections followed by pneumonia, cellulitis, and bacteremia, while pneumonia carries the highest risk of mortality. The incidence of MDR bacterial infections has been increasing, especially in healthcare-associated settings. Second infections that develop during hospitalization, multiple organ failures, and high MELD score are associated with poor survival. Preventive measures, early diagnosis, and adequate treatment of infections are essential key concepts in minimizing morbidity and mortality in patients with cirrhosis.

Active immunization for prevention of De novo hepatitis B virus infection after adult living donor liver transplantation with a hepatitis B core antigen-positive graft

De novo hepatitis B virus (DNHB) infections may occur in recipients who do not receive prophylaxis after liver transplantation (LT) with antibody to hepatitis B core antigen (anti-HBc)-positive donor grafts. Active immunization has been shown to prevent DNHB in pediatric recipients. Our aim is to investigate the efficacy of HBV vaccination for preventing DNHB in adult living donor liver transplantation (LDLT). In total, 71 adult antibody to hepatitis B surface antigen (anti-HBs)-negative LDLT patients who received anti-HBc+ grafts from 2000 to 2010 were enrolled into this study. Patients were given hepatitis B virus vaccinations with the aim of achieving anti-HBs > 1000 IU/L before transplant and >100 IU/L after transplant. The cohort was stratified into 3 groups: patients with pretransplant anti-HBs titer of > 1000 IU/L without the need for posttransplant prophylaxis (group 1, n = 24), patients with pretransplant low titer of <1000 IU/L who were given posttransplant lamivudine prophylaxis and responded appropriately to posttransplant vaccination by maintaining anti-HBs titers of > 100 IU/L (group 2, n = 30), and low titer nonresponders (anti-HBs titer of < 100 IU/L despite vaccination), for whom lamivudine was continued indefinitely (group 3, n = 17). All DNHB occurred in group 3 patients with posttransplant anti-HBs levels of < 100 IU/L, with an incidence rate of 17.6% compared with 0% in patients with posttransplant anti-HBs levels of > 100 IU/L (P = 0.001). A pretransplant anti-HBs level of >1000 IU/L was significantly associated with early attainment and a sustained level of posttransplant anti-HBs of >100 IU/L (P < 0.001). Active immunization is effective in preventing DNHB in adult LDLT if the posttransplant anti-HBs level is maintained above 100 IU/L with vaccination. Antiviral prophylaxis can be safely discontinued in patients who obtain this immunity. Liver Transplantation 23 1266-1272 2017 AASLD.

Response to hepatitis B vaccination in patients with liver cirrhosis

Hepatitis B vaccination is strongly recommended for all infants and children but also for adults who are at risk of HBV infection. Attempts to immunize patients with liver cirrhosis have been proven relatively ineffective, and several strategies have already been used to improve the immune response in this group. The primary aim of this review is to examine, discuss, and summarize the immunogenicity of hepatitis B vaccination in patients with liver cirrhosis. MEDLINE search identified 11 studies (n = 961). The dose of the vaccine and the schedule of the vaccination varied. The response rates to the HBV vaccination ranged from 16% to 87% among patients with cirrhosis regardless of the number and vaccine dose. In particular, patients who received the standard dose of vaccination achieved seroprotection rates ranged from 16% to 79% (mean response rate 38%) and those who received a double dose achieved relatively better seroprotection rates (range: 26%-87%; mean response rate 53%). The overall mean response rate to the HBV vaccination was 47%. In conclusion, cirrhotic patients achieve lower seroprotection rates after the completion of HBV vaccination series. Several strategies have tried to improve the immunogenicity; however, there is a great need for additional studies to further explore (1) the immune response in relation to poor vaccination responsiveness confounding factors, (2) novel strategies to improve immunogenicity, and (3) the immune mechanism underlying the differences in response rates to HBV vaccination.

Endotoxemia contributes to CD27+ memory B-cell apoptosis via enhanced sensitivity to Fas ligation in patients with Cirrhosis

Peripheral CD27⁺ memory B-cells become quantitatively reduced and dysfunctional in patients with cirrhosis through poorly characterized mechanisms. We hypothesized that the disappearance of CD27⁺ memory B-cells results from enhanced sensitivity to apoptosis caused by exposure to gut microbial translocation products. Using isolated naïve and memory B-cells from patients with cirrhosis and age-matched controls, ex vivo and activation-induced sensitivity to Fas-mediated apoptosis was assessed under relevant experimental conditions. We observed differential expression of CD95(Fas) in CD27⁺ B-cells from cirrhotic patients that was inversely correlated with peripheral CD27⁺ B-cell frequency. While memory B-cells from cirrhotic patients were resistant to Fas-mediated apoptosis ex vivo, Toll-like receptor 4(TLR4)-ligation restored Fas-sensitivity. Sensitivity to Fas-mediated apoptosis could be transferred to healthy donor memory B-cells by co-culturing these cells with plasma from cirrhotic patients, a sensitivity partially mediated by Fas and TLR4 signaling, and partially rescued via B-cell receptor crosslinking. We conclude that peripheral CD27⁺ memory B-cells in cirrhosis exhibit increased sensitivity to Fas-induced apoptosis in an activation-dependent manner to which endotoxin contributes, associated with reduced frequency of circulating memory B-cells. Destruction of this critical cell subset may contribute to the cirrhotic immunodeficiency state and heightened risk of systemic infections in advanced liver disease.

Hepatitis B and C serologic profiles of Canadian organ donors and recipients: retrospective 10-year review at a single center

BACKGROUND

Hepatitis C virus (HBV) and hepatitis C virus (HCV) are important causes of hepatitis and can be transmitted from organ donor to recipient. This study aimed to determine HBV and HCV serologic profiles of a population of Canadian solid organ transplant (SOT) donors and recipients, including prevalence of recipient HBV immunity.

METHODS

Data on age, gender, organ transplanted, and pre-transplant HBV and HCV serology for SOT donors and recipients at a Canadian hospital from 2001 to 2011 were obtained from a transplant database.

RESULTS

There were 2455 recipients (2205 adults, 250 children), and 1559 donors. Over 50% of adult and 44% of pediatric recipients were HBV non-immune pre-transplant. Pediatric recipients were more likely to have HBV vaccine immunity than were adult recipients (48.8% vs. 28.9%, P < 0.001). Prevalence of HBV vaccine immunity was highest in renal recipients (48.3% in adult, 63.2% in pediatric recipients). Recipient HBV vaccine immunity increased from 5.8% in 2001 to 44.5% in 2011 (P < 0.001). Of 134 adult recipients with prior HBV infection, 59 (44%) were co-infected with HCV. Only 0.6% of adult non-liver recipients had acute or chronic HBV infection and 3.2% were anti-HCV positive. Only 2 donors had acute or chronic HBV infection, 29 had prior HBV infection, 9 were isolated hepatitis B core antibody positive, and 15 were anti-HCV positive.

CONCLUSIONS

The prevalence of HBV vaccine immunity in SOT candidates is low, but increased from 2001 to 2011. Opportunities for quality improvement in pre-transplant HBV immunization exist. HCV co-infection is common in recipients with prior HBV infection. Prevalence of HCV infection in non-liver transplant recipients is low.

Vaccination of immunocompromised patients

Vaccination of immunocompromised patients is challenging both regarding efficacy and safety. True efficacy data are lacking so existing recommendations are based on immune responses and safety data. Inactivated vaccines can generally be used without risk but the patients who are most at risk for infectious morbidity and mortality as a result of their severely immunosuppressed state are also those least likely to respond to vaccination. However, vaccination against pneumococci, Haemophilus influenzae and influenza are generally recommended. Live vaccines must be used with care because the risk for vaccine-associated disease exists.

Escape hepatitis B virus mutations in recipients of antibody to hepatitis B core antigen-positive liver grafts receiving hepatitis B immunoglobulins

A variety of prophylactic strategies are used to prevent the risk of hepatitis B virus (HBV) transmission from antibody to hepatitis B core antigen (anti-HBc)-positive donors. The mechanisms underlying the failure of HBV immunoglobulin monoprophylaxis have been poorly evaluated. Seventy-seven anti-HBc-positive grafts were used in 21 hepatitis B surface antigen (HBsAg)-positive recipients and 56 HBsAg-negative recipients. HBsAg-positive recipients received prophylaxis comprising hepatitis B immunoglobulins (HBIG) and antiviral agents, 45 HBsAg-negative recipients received a modified HBIG regimen, and 11 HBsAg-negative recipients received no prophylaxis. Both donors and recipients were screened for HBsAg, antibody to HBsAg (anti-HBs) and anti-HBc in their sera and for HBV DNA in both their sera and liver. S gene mutations were investigated after HBV reinfection. HBV infection occurred in 15 HBsAg-negative recipients (19.4%) at a median interval of 16 months (range = 6-67 months) post-transplant and in none of the HBsAg-positive recipients. HBV infections were observed in 31.6% of HBV-naive recipients and 7.7% of HBV-immune recipients receiving HBIG prophylaxis versus 100% of HBV-naive recipients (P = 0.0068) and 33% of HBV-immune recipients (P = 0.08) with no such prophylaxis. S gene mutations were identified in 9 recipients. In conclusion, priority should be given to using anti-HBc positive grafts for HBsAg-positive or HBV-immune recipients. Our study has confirmed the high risk of HBV transmission to naive recipients. HBIG monoprophylaxis was associated with a significant risk of de novo HBV infection and HBV escape mutations. In these patients, we therefore recommend prophylaxis with lamivudine or new nucleos(t)ides analogues. The potential benefits of HBIG prophylaxis combined with antiviral drugs require further evaluations. Long-term prophylaxis is needed because of the long interval of de novo HBV infection post-transplant in some patients.

Hepatitis B vaccination: The key towards elimination and eradication of hepatitis B

Hepatitis B virus infection is a global health problem. Worldwide, about 360 million people are chronically infected with the virus. They continue to spread the virus to others and are themselves at risk of chronic liver diseases and hepatocellular carcinoma. The infection can now be treated by antivirals or interferons and the transmission route can be interrupted. Nevertheless, the most effective means is to immunize all susceptible individuals, especially young children, with safe and efficacious vaccines. The combined efforts of vaccination, effective treatment and interruption of transmission make elimination of the infection plausible and may eventually lead to eradication of the virus. Because hepatitis B vaccination has a key role in the control of hepatitis B, properties of this vaccine, its effectiveness in pre-exposure and post-exposure settings, duration of protection after vaccination and the need of booster doses are discussed. Mass hepatitis B vaccination in children decreases the carriage of the virus, and the diseases associated with acute and chronic infection, including hepatocellular carcinoma. Challenges that need to be solved to expand mass vaccination, and the strategies towards elimination and eventual eradication of hepatitis B in the world are also discussed.

Successful hepatitis B vaccination in liver transplant recipients with donor-specific hyporesponsiveness

Currently, patients are prescribed lifelong treatment with hepatitis B immunoglobulin (HBIg) after liver transplantation (LT) for hepatitis B virus (HBV)-related diseases in order to prevent reinfection with HBV. Active immunization with an HBV vaccine would be a preferable alternative; however, the immunosuppressive environment in LT recipients is believed to elicit a poor response to vaccination. Minimizing the exposure of the HBV-infected LT recipients to immunosuppressants would be beneficial in inducing adaptive immunity against HBV by vaccination. In this study, in addition to efforts to minimize immunosuppression, prophylaxis with HBV vaccination combined with continuous HBIg administration was performed in 17 LT recipients who had undergone transplantation attributable to HBV-related diseases. During the observation period, the overall response rate to HBV vaccination was 64.7%. The immune status of the recipients was evaluated by a mixed lymphocyte reaction assay in response to allostimulation. Patients showing a donor-specific hyporesponse with a well-maintained response to the third-party stimulus always achieved a sustained immune response to the vaccine, whereas patients showing a hyporesponse to both the donor and the third-party stimulus were unable to do so. Thus, inducing an anti-donor-specific immunosuppressive status by minimizing immunosuppression should enable post-transplant HBV vaccination to be a promising prophylactic strategy.

Hepatitis B virus prevention strategies for antibody to hepatitis B core antigen-positive liver donation: a survey of North American, European, and Asian-Pacific transplant programs

Prophylactic therapy is generally used to prevent reactivated hepatitis B after transplantation of an antibody to hepatitis B core antigen (anti-HBc)-positive liver. To gain insight into current practice, a questionnaire was e-mailed to 89 liver transplant physicians in the United States, Europe, and Asia/Australia and 4 hepatitis B experts. Addressees were asked if they prefer lamivudine or other nucleoside analogs and whether these drugs are used indefinitely. They were also questioned about the use of hepatitis B immune globulin (HBIg), the preferred duration of its administration, and whether treatment strategies differ according to the knowledge of the serologic status of the recipient. Responses were obtained from 78 physicians. All transplant physicians reported the use of nucleoside analog therapy, and 65% prefer lamivudine (58% versus 81% for US and non-US physicians, P = 0.05). Sixty-one percent use HBIg (38% always, 23% sometimes). HBIg was used more frequently in the United States than other parts of the world (69% versus 46%, P = 0.03). Eighty-one percent of transplant physicians use nucleoside analog therapy for an indefinite period, but the duration of HBIg treatment varies widely. Although some centers omit nucleoside analog or HBIg therapy in antibody to hepatitis B surface antigen-positive recipients, 90% will not omit these agents if the recipient is positive for anti-HBc alone. In conclusion, nucleoside analog therapy is nearly always used for anti-HBc-positive livers, and most transplant physicians treat for an indefinite period. Lamivudine continues to be preferred as first-line therapy. Many programs also use HBIg, but there is wide variation in the way this is administered. Further study is needed to determine the most cost-beneficial regimen.

High-titer antibody to hepatitis B surface antigen before liver transplantation can prevent de novo hepatitis B infection

OBJECTIVE

De novo hepatitis B virus (HBV) infection is defined as infection occurring in HBV surface antigen (HBsAg)-negative patients who become HbsAg positive after organ transplantation. We assessed the incidence and risk factors of de novo HBV infection in pediatric liver transplant recipients.

PATIENTS AND METHODS

From 1996 to 2006, 71 Taiwanese children with non-HBV-related liver diseases underwent orthotopic liver transplantation (OLT) at the National Taiwan University Hospital. All of the surviving recipients were tested regularly for liver function, serum levels of immunosuppressant, HBsAg, titers of antibodies to hepatitis B surface antigen (anti-HBs), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C virus (anti-HCV). HBV vaccination histories and the anti-HBs titers before OLT were recorded. No regular prophylaxis was given.

RESULTS

Fifty-nine patients (33 girls and 26 boys) were followed up for a median of 4.4 years (range 1.0-10.0). Of those, 36 (61.0%) received allografts from anti-HBc-positive and HBsAg-negative donors. De novo HBV infection was found in 9 (15.3%) patients after OLT, 8 of whom received allografts from HBsAg-negative and anti-HBc-positive donors. Forty-eight (81.4%) patients received 3 or more doses of HBV vaccine before OLT. Pre-OLT anti-HBs titers were available for 49 recipients. Of the 9 de novo HBV-infected recipients, 8 had anti-HBs titers <200 mIU/mL. No graft loss or fulminant hepatitis was noted.

CONCLUSIONS

In the absence of adequate prophylaxis, the incidence of de novo HBV infection in pediatric OLT recipients is 15.3%. An anti-HBs titer of >200 mIU/mL before OLT may be sufficient to prevent de novo HBV infection in HBsAg-negative recipients.

Liver transplantation using hepatitis B core antibody-positive grafts: review and university of Tokyo experience

Hepatitis B surface antigen-negative and hepatitis B core antibody-positive grafts were considered unsuitable for transplantation. The number of potential recipients for liver transplantation now exceeds that of potential donor organs, which has led us to reevaluate the feasibility of these grafts. Several strategies involving prophylactic administration of hepatitis B immunoglobulin and/or lamivudine to transplant recipients have been proposed. At the University of Tokyo, we have continued to use hepatitis B immunoglobulin monoprophylaxis with zero recurrence. In this article we report our experience with the use of hepatitis B surface antigen-negative/hepatitis B core antibody-positive grafts with hepatitis B immunoglobulin monotherapy. We conducted a review of the literature regarding the feasibility of these grafts to reconfirm optimal prophylactic strategies for preventing de novo hepatitis B virus infection in transplant recipients.

The Cost-Effectiveness of Two Strategies for Vaccinating U.S. Veterans with Hepatitis C Virus Infection against Hepatitis A and Hepatitis B Viruses

OBJECTIVES

Although hepatitis A and B vaccinations are recommended for patients with chronic hepatitis C virus (HCV), the ideal vaccination strategy has not been determined. Our objective was to model the cost-effectiveness of two strategies for vaccinating patients with HCV infection against hepatitis A (HAV) and hepatitis B (HBV) viruses. The strategies evaluated were: universal vaccination with the combined HAV and HBV vaccine, and selective vaccination based on immunity determined by blood testing.

METHODS

A decision tree model was constructed to compare the cost-effectiveness of the two vaccination strategies from the New Mexico Veterans Affairs Health Care System (NMVAHCS) perspective. A retrospective review of all HCV patients (2517 subjects) at the NMVAHCS was performed to extract prevalence of immunity to HAV and HBV, and prevalence of decompensated liver disease. Literature review was performed to obtain other probabilities for the model. Only direct medical costs were considered; the effectiveness measure was the number of patients immune to both HAV and HBV. Sensitivity analyses were performed to test robustness of the results to changes in input variables. All costs were in 2004 US dollars.

RESULTS

The selective strategy was less costly but less effective, with a cost-effectiveness ratio of 105 dollars per patient immune to HAV and HBV. The universal strategy was more effective but more expensive with a cost-effectiveness ratio of 112 dollars per patient immune to HAV and HBV. Compared with the selective strategy, universal strategy was associated with an incremental cost-effectiveness (ICE) ratio of 154 dollars per additional patient immune to HAV and HBV. The universal strategy would become more cost-effective if 1) the cost of combined vaccine was reduced to less than 30.75 dollars (9.7% reduction), 2) the cost of HBV vaccine increased to greater than 34.50 dollars (25% increase), 3) the cost of blood tests for immunity increased to more than 25.25 dollars (23% increase), or (4) the prevalence of anti-HBs decreased to less than 24%.

CONCLUSIONS

The selective vaccination strategy for HAV and HBV in our sample of patients with HCV is more cost-effective. However, the universal strategy is more effective and its ICE is minimal, thus it may be worth the additional cost.

Immunization issues before and after solid organ transplantation in children

Solid-organ transplant recipients are at risk from various infectious diseases, many of which can be prevented by immunizations that could reduce morbidity and mortality. However, it is not uncommon for children requiring transplantation to have received inadequate or no immunizations pre-transplant. Every effort should be made to immunize transplant candidates early in the course of their disease according to recommended schedules prior to transplantation. It is also important to immunize their household contacts and healthcare workers. In this review, we summarize the major immunization issues for children undergoing transplantation, the data currently available on immunization safety and efficacy, and suggest immunization practices to reduce vaccine-preventable disease. There is a real need for a standardized approach to the administration and evaluation of immunizations in this group of patients.

Recombinant hepatitis B vaccine (Engerix-B): a review of its immunogenicity and protective efficacy against hepatitis B

Engerix-B (Hep-B[Eng]) is a noninfectious recombinant DNA vaccine containing hepatitis B surface antigen (HBsAg). It is produced from genetically engineered yeast (Saccharomyces cerevisiae). Intramuscular Hep-B(Eng) [0-, 1-, 6-month schedule] has excellent immunogenicity in healthy neonates and infants, children, adolescents and adults, with seroprotection rates of 85-100% seen approximate, equals 1 month after the final dose of vaccine; seroprotection was defined as an antibody against HBsAg (anti-HBs) titre of > or =10 IU/L. The use of alternative Hep-B(Eng) immunisation schedules (e.g. a 0-, 1-, 2-, 12-month schedule in neonates and infants, 0-, 12-, 24-month or two-dose schedules in children and adolescents, and accelerated schedules in adults) have also been associated with high rates of seroprotection. Seroprotection rates were generally similar with Hep-B(Eng) and the recombinant vaccine Recombivax HB (Hep-B[Rax]) or plasma-derived vaccines (PDVs) approximate, equals 1 month after the final dose (although anti-HBs geometric mean titres were significantly higher with Hep-B[Eng] than with Hep-B[Rax]). One month after the final dose, adults had significantly higher seroprotection rates with the recombinant triple-antigen vaccine Bio-Hep-B (Hep-B[Bio]) than with Hep-B(Eng), although seroprotection rates in healthy infants were similar with Hep-B(Eng) and Hep-B(Bio). Hep-B(Eng) had excellent immunogenicity in several groups considered at high risk of acquiring hepatitis B (e.g. neonates born to hepatitis B carrier mothers and healthcare workers). The immunogenicity of Hep-B(Eng) was reduced in patients with conditions associated with impaired immune function (e.g. patients undergoing haemodialysis or being treated for malignancy), although it had good immunogenicity in patients with diabetes mellitus.Hep-B(Eng) had excellent protective efficacy against HBsAg carriage in healthy infants and children, and in neonates born to hepatitis B carrier mothers (protective efficacy of 95-99%). Hep-B(Eng) also demonstrated good protective efficacy in a number of other high-risk groups. Hep-B(Eng) is generally well tolerated with a tolerability profile similar to that of Hep-B(Rax), Hep-B(Bio) and PDVs. In conclusion, Hep-B(Eng) is a well established, highly immunogenic hepatitis B vaccine with good tolerability and excellent protective efficacy; it offers flexibility through a variety of immunisation schedules. In addition, it appears that Hep-B(Eng) confers immunity for at least 10 years. Hep-B(Eng) has an important role in mass vaccination campaigns against hepatitis B, as well as in groups considered at high risk of acquiring hepatitis B.

Vaccinations for adult solid-organ transplant recipients: current recommendations and protocols

Recipients of solid-organ transplantation are at risk of severe infections due to their life-long immunosuppression. Despite emerging evidence that vaccinations are safe and effective among immunosuppressed patients, most vaccines are still underutilized in these patients. The efficacy, safety, and protocols of several vaccines in this patient population are poorly understood. Timing of vaccination appears to be critical because response to vaccinations is decreased in patients with end-stage organ disease and in the first 6 months after transplantation. For these reasons, the primary immunizations should be given before transplantation, as early as possible during the course of disease. Vaccination strategy should include vaccination of household contacts and health care workers at transplant centers unless contraindicated. No conclusive data are available on the use of immunoadjuvants and screening for protective titers. Most vaccines appear to be safe in solid-organ transplantation recipients, but live vaccines should be avoided until further studies are available. The risk of rejection appears minimal. Recommended vaccines include pneumovax, hepatitis A and B, influenza, and tetanus-diphtheria. We outline specific protocols and recommendations in this particular patient population. Specific contraindications exist for other vaccines, such as yellow fever, oral polio vaccine, bacillus Calmette-Guerin, and vaccinia. We conclude that solid-organ recipients will benefit from consistent immunization practices. Further studies are recommended to improve established protocols in this patient population.

Hepatitis B vaccination in liver transplant candidates

Liver transplantation has become the treatment of choice for patients with end-stage liver disease. De novo hepatitis B infection after liver transplantation is a rare event and usually runs a mild clinical and histological course. Despite the favourable outcome, a wide spectrum of hepatitis B virus (HBV)-associated liver disease may develop, ranging from asymptomatic carriage to severe chronic active hepatitis or cirrhosis and even fulminant hepatic failure. The achievement of protective titres of anti-HBs through vaccination has been suggested to be protective against the development of de novo HBV infection. The results of vaccination in cirrhotic patients awaiting for liver transplant have been very disappointing. High-dose/short-term schedules have been tried in transplant candidates in order to increase the response rate. New and more immunogenic formulations (containing new adjuvants or additional pre-S1/pre-S2 recombinant antigens), and, more importantly, early vaccination of potential transplant candidates at earlier stages of their liver disease should further prevent de novo hepatitis B in transplant recipients.

Immunogenicity of two accelerated hepatitis B vaccination protocols in liver transplant candidates

OBJECTIVE

It is common practice to immunize patients against hepatitis B virus infection prior to orthotopic liver transplantation (OLT). We compared the seroprotection rates of two accelerated schedules with a recombinant hepatitis B vaccine in patients awaiting OLT.

DESIGN AND METHODS

Patients were prospectively recruited and vaccinated with either 20 micrograms (group 1, n = 14) or 40 micrograms (group 2, n = 20) hepatitis B surface antigen per dosage. Thirty-nine healthy volunteers served as a historical control group. Patients in all groups were vaccinated with an accelerated schedule (0, 7 and 21 days). All patients underwent clinical and laboratory examinations (HBs antibodies, CD4/CD8 ratio, transaminases).

RESULTS

The accelerated hepatitis B vaccination schedules were well tolerated. Eight weeks after the third injection, no significant differences in seroprotection rates were observed between group 1 (31%) and group 2 (26%). There was no correlation with respect to seroconversion rates and gender, smoking habits or CD4/CD8 ratio.

CONCLUSION

These data suggest that accelerated vaccination schedules with a recombinant hepatitis B vaccine are safe and well-tolerated, but only achieve poor seroconversion rates in OLT candidates. Increasing the vaccine dose to 40 micrograms hepatitis B surface antigen per injection did not result in a higher response rate. Because of the low risk of acquiring de novo hepatitis B infection after transplantation, it should be questioned whether routine hepatitis B vaccination with standard recombinant vaccines prior to liver transplantation should be recommended any longer.

Successful immune response to a recombinant hepatitis B vaccine in children after liver transplantation

BACKGROUND

Patients who undergo liver transplantation require multifaceted general care, and vaccination has a fundamental role before and after transplantation. The purpose of this study was to provide a prospective evaluation of the immunogenicity of the recombinant vaccine (RV) against Hepatitis B in pediatric patients with liver transplants (TxH) who for different reasons did not receive a pretransplantation vaccine.

METHODS

From June 1996 to December 1999, 47 pediatric patients with liver transplants were vaccinated with RV. Patients older than 1 year of age, in stable condition, and 6 months post-transplantation were included. The vaccination scheme was 0-1 and 6 months, intramuscular 10 microg in less than 30 kg body weight, and 20 microg in more than 30 kg body weight. The nonresponder patients were vaccinated with a booster dose and a double dose 1 to 6 months after the last dose. Responders to titer HBs Ab enzyme immunoassay (EIA) <10 UI/ml were defined as nonresponders, to titer between 10-100 UI/ml as responders, and to higher titer of 100 UI/ml as high responders.

RESULTS

The following data were obtained from the 47 patients: mean +/- standard deviation (SD) age at vaccination was 10.76 +/- 5.96 years old and the mean +/- SD post-transplant time at the beginning of vaccination was 3.56 +/- 2.19 years. Thirty-three of 47 patients (70%) responded to doses according to body weight, and 14 (30%) did not respond, necessitating a booster dose after which 7 responded (50%). The global seroconversion was 85%. There was not a significant responder cyclosporine concentration dosage (154 vs. 150 ng/ml) difference between responders and nonresponders. Sixty-six percent (8 of 12) of patients receiving a triple immunosuppressive scheme (cyclosporine, steroids, and Azathioprine) had a positive response, while 84% (16 of 19) receiving a double scheme (cyclosporine and steroids) and 100% (16 of 16) receiving monotherapy with cyclosporine had a positive response. By comparing a triple scheme with monotherapy, the Fisher exact test found a P < 0.01. Incidence of adverse effects (local pain) was 2.63%.

CONCLUSION

Immunization with RV was well-tolerated with acceptable seroconversion and safety in recipients after liver transplantation, particularly in those undergoing cyclosporine monotherapy. The population studied showed better results than did other populations of immunosuppressed patients.