Immunogenicity of a yeast-derived hepatitis B vaccine in hemodialysis patients

Lower Long-term Efficiency of Intradermal Hepatitis b Vaccine Compared to the Intramuscular Route in Hemodialysis Patients

Intramuscular (IM) and Intradermal (ID) vaccination against hepatitis B (HB) are efficient in hemodialysis patients. We retrospectively analysed the response of 32 patients during 48 consecutive months and compared the results of the two vaccination routes using the recombinant vaccine (Engerix, SKB).

Thirteen patients were vaccinated with 5 mcg ID every 2 weeks (total 8 doses), plus an IM dose on month (M) 12 (group A). Nineteen patients (group B) were vaccinated with 4 IM doses of 20 mcg each, on months M0, 1, 2 and 12.

HB antibodies were measured on M5, M11, M13, M24, M36 and M48. An additional 20 mcg IM dose was given with titers below 10 mIU/ml. Seroconversion, seroprotection and antibody levels were equivalent in both groups up to M13; with the exception of seroconversion rates, a significantly different response was observed afterwards (A/B, in mIU/ml): M5: 399 ± 107 vs 342 ± 69, M13: 536 ± 118 vs 673 ± 61, M24: 278 ± 94 vs 595 ± 81, P=0.02, and M48: 68 ± 29 vs 565 ± 92, P=0.003. Early HBSAB levels did not correlate with those found four years later in both groups. An additional booster dose was given 8 times in 4 group A patients (1–3 doses/patient) and 3 times in 1 group B patient.

Immune response to HB vaccine in hemodialysis patients is initially equivalent by both immunization routes. Late antibody titers were found significantly lower in ID immunization with more frequent booster doses needed.

Primary seroresponses to double-dose compared with standard-dose hepatitis B vaccination in patients with chronic kidney disease: a systematic review and meta-analysis

Background

Clinical guidelines recommend double-dose hepatitis B vaccination for patients requiring dialysis, due to an increased risk of hepatitis B infection and reduced vaccine responsiveness. There are no recommendations for patients with chronic kidney disease (CKD) prior to dialysis.

Methods

We performed a systematic review and meta-analysis of randomized and quasi-randomized trials comparing efficacy (seroresponses) and harms of double-dose compared with standard-dose hepatitis B vaccination in patients with CKD, including those requiring dialysis. A systematic literature search (CENTRAL, MEDLINE and EMBASE) was performed using a predetermined search strategy. Relative risks were calculated from pooled data using a random-effects model with subgroup analysis by dialysis requirement and vaccine type.

Results

Seven studies (501 patients) fulfilled review criteria: four in patients receiving dialysis and three in patients not receiving dialysis. The incidence of seroconversion was not increased with double-dose vaccination overall [risk ratio (RR) 1.17, 95% confidence interval (CI) 0.98-1.39], by dialysis requirement or vaccine type. The incidence of seroprotection (reported by only four studies) was increased with double-dose vaccination overall (RR 1.53, 95% CI 1.17-2.00) but not by dialysis requirement. Adverse events were not reported by treatment arm, precluding comparison. The overall quality of included studies was moderate to low.

Conclusions

The current data do not support clinical guideline recommendations for administering double-dose vaccination for patients with CKD as seroconversion was not improved and seroprotection was inadequately assessed. Large high-quality studies are required to overcome the current evidence gap regarding vaccine dosing in CKD.

Vaccination strategies in patients with IBD

Patients with IBD are at increased risk of infection, in part owing to the disease itself, but mostly because of treatment with immunosuppressive drugs. Although many of these infections are vaccine-preventable, vaccination coverage in patients with IBD is extremely low. The vaccine strategies examined in this Review are based on data that enable us to provide practical advice for clinicians. Clinical evidence indicates that vaccines do not increase the risk of relapse in patients with IBD. Live vaccines are contraindicated in immunocompromised individuals, but inactivated vaccines can be safely administered. Most patients receiving immunosuppressive therapy develop an immune response after vaccination, but response rates might differ from those of nonimmunosuppressed individuals. Therefore, vaccination status should be checked and updated upon diagnosis of IBD.

Comparison of the effectiveness of two protocols for vaccination (standard and double dosage) against hepatitis B virus in patients with inflammatory bowel disease

BACKGROUND

The response rate to hepatitis B virus (HBV) vaccination in patients with inflammatory bowel disease (IBD) is low.

AIM

To compare two vaccination protocols-the standard dose and the double dose-in IBD patients.

METHODS

Patients diagnosed with IBD from three tertiary hospitals were vaccinated against HBV with two different protocols: the standard protocol (Engerix-B single dose at 0, 1 and 6 months) and the new faster protocol based on a double dose (Engerix B double dose at 0, 1 and 2 months). Anti-HBs titres were measured 1-3 months after the last dose. A multivariate analysis was performed to identify factors that were predictive of response to the vaccine.

RESULTS

The study sample comprised 148 patients (mean age 40 years, 69% Crohn's disease), 70% of whom were receiving immunosuppressive therapy (22% thiopurines, 23% anti-TNF and 25% both). The standard protocol was followed in 46% of patients and the double dose protocol in 54%. Considering anti-HBs >10 IU/L as a successful response to vaccination, the seroconversion rate was higher among patients vaccinated with the double dose than with the standard dose: 75% (95% CI, 65-85%) vs. 41% (95% CI, 29-54%) (P < 0.001). In the multivariate analysis, vaccination with the double dose was the only factor associated with a better response to the vaccine (OR, 4; 95% CI, 2-8; P < 0.001).

CONCLUSIONS

The response rate to the HBV vaccination in IBD patients is low. Administration of a double dose was associated with a higher response rate. Therefore, the double dose protocol could be a suitable option in patients with IBD.

High rates of serological response to a modified hepatitis B vaccination schedule in HIV-infected adults subjects

We evaluated a modified HBV regimen in a cohort of HIV-infected subjects in Rio de Janeiro, Brazil. HIV-infected subjects with no serologic evidences of previous hepatitis B infection were immunized with 4 doses (40 microg each) of recombinant hepatitis B vaccine given at 0, 1, 2 and 6 months. Blood samples were collected 1 month after the last dose and anti-HBs titers were measured. A protective antibody response was defined as an anti-HBs titer >or=10 mIU/mL. Forty-seven subjects (30 women, 17 men; mean age was 36 years, ranging from 21 to 58 years) were included in the final analysis. Median baseline CD4+ lymphocyte count was 402 cells/mm(3) and 33 subjects (70%) had an HIV viral load below 80 copies/mL. A protective antibody response was observed in 42 (89%) subjects. Thirty-seven (78%) and 28 (60%) patients developed anti-HBs titers higher than 100 mIU/mL and 1000 mIU/mL, respectively. 1 out of 5 non-responders (20%) had an HIV viral load below the detection limit, in contrast with 32 (76%) of those with an adequate serologic response (p=0.02). These findings suggest that 4-double dose alternative schedule may be considered to overcome the lower seroconversion rates observed with the standard regimens in HIV-infected subjects.

T cell responses to hepatitis B surface antigen are detectable in non-vaccinated individuals

AIM: To evaluate, whether humoral hepatitis-B-vaccine non-responders also fail to mount a T cell response and to compare these results to normal vaccines.

METHODS: Fourty-seven health care employees were enrolled in this study including all available non-responders (n = 13) with an anti-HBsAg titer < 10 kU/L and all available low-responders (n = 12) with an anti-HBsAg titer < 100 kU/L. Also, 12 consecutive anti-HBsAg negative pre-vaccination subjects were enrolled as well as 10 subjects (+7 from the vaccinated group) with titers > 1000 kU/L as controls. PBMC from all subjects were analyzed by IFN-γ and IL-4 ELISPOT assays for the presence of hepatitis B surface antigen (HBsAg) reactive T cells.

RESULTS: Non-responders and low-responders had no or only very limited T cell responses, respectively. Individuals responding to vaccination with the induction of a high anti-HBsAg titer showed a strong T cell response after the third vaccination. Surprisingly, these individuals showed response even before the first vaccination. T cell response to control antigens and mitogens was similar in all groups.

CONCLUSION: Our data suggest that there is no general immune deficiency in non-/low-responders. Thus, we hypothesize that the induction of anti-HBsAg responses by vaccination is significantly dependent on the pre-existing T cell repertoire against the specific antigen rather than the presence of a general T cell defect.

Assessment of long-term efficacy of hepatitis B vaccine

In a healthy cohort of 462 subjects in which hepatitis B vaccine was administered between 1990 and 1992 a follow-up study was carried out to determine the duration of protection. Individuals with antibody against the hepatitis B virus surface antigen (anti-HBs) titer lower than 100 mIU/ml were administered a booster dose and antibodies determined 30 days later. The proportion of protection 6.5 years after vaccination was 85% (95% CI: 82-88). Only nine vaccinees seroconverted to anti-HBc positivity without becoming carrier or ill. In 125 subjects in which a booster dose was administered a significant increase in geometric mean of anti-HBs titer was observed (609 mIU/ml) as compared to late (13 mlU/ ml) and early post-vaccination antibody levels (256 mIU/ml, Wilcoxon's test, p < 0.001) suggesting the existence of an anamnestic response. We conclude that in immunocompetent population it is not necessary to administer a booster dose 6.5 years after hepatitis B vaccination.

Increasing the number of hepatitis B vaccine injections augments anti-HBs response rate in HIV-infected patients. Effects on HIV-1 viral load

Preventing hepatitis B by vaccination is essential in HIV-infected patients (higher progression rate of HBV infection to chronicity, lower rate of serum HBe Ag loss). However, it has been shown a decreased anti-HBs response in these individuals after a standard vaccination (3 doses of 20 micrograms). Thus, we tested the hypothesis that doubling the number of hepatitis B vaccine injections might increase anti-HBs response rate. HIV-infected patients with CD4 > 200/microliter, who were on stable antiretroviral treatment, as well as seronegative for HBV markers, and who have never been vaccinated against HBV, were given 3 intramuscular injections of Genhevac B 20 micrograms at 1 month intervals. Initial non responders were given 3 additional monthly injections. Anti-HBs titer was followed. We also evaluated the effects on HIV-1 viral load. Twenty patients with a median CD4 cell count of 470/microliter were enrolled. The response rate after three 20 micrograms injections was 55% (11/20), lower in individuals with CD4 between 200 and 500/microliter (4/12 = 33.3%), compared to patients with CD4 above 500/microliter (7/8 = 87.5%, P = 0.02). Among 9 initial non-responders, only 2 did not respond to 3 additional doses; thus, the overall response rate was 90% (18/20). Geometric mean titers of anti-HBs were 133 IU/l and 77.5 IU/l, after 3 and 6 Genhevac doses, respectively (P = 0.38). One year later, only 10/17 (58.8%) patients had protective anti-HBs. Five patients experienced a significant viral load increase, transient in 3 cases. These preliminary results suggest that doubling the number of hepatitis B vaccinations in HIV-infected patients might significantly improve anti-HBs response rate; however, close monitoring of anti-HBs is necessary because of its short-lived persistence. The effects on HIV-1 viral load are limited.

Efficacy of a high and accelerated dose of hepatitis B vaccine in alcoholic patients: a randomized clinical trial

PURPOSE

A randomized, double-blind trial was conducted to compare the efficacy of a high-dose versus standard-dose hepatitis B vaccine in alcoholic patients.

PATIENTS AND METHODS

One hundred ten alcoholic patients were randomized to either receive the standard dose (20 micrograms at 0.1, and 6 months) or a high dose (40 micrograms at 0, 1, 2, and 6 months) of recombinant hepatitis B vaccine (Engerix-B). Patients were monitored for relapse of drinking using self-report, serial serum carbohydrate deficient transferrin, and collateral verification. The final titer of antibody to hepatitis B surface antigen (anti-HBs) was obtained 12 months after the first vaccine dose; a seroconversion was defined as a titer greater than 10 mlU/ml.

RESULTS

One hundred subjects completed the study; 10 of these had clinical or pathological evidence of cirrhosis. Thirty-six out of 48 (75%) of patients administered the high-dose regimen seroconverted compared with 24 of 52 (46%) in the standard dose group (P < 0.005). The mean anti-HBs titer of the high dose group was significantly greater than of the standard dose group (76.4 versus 39.4 mlU/ml, P < 0.01). Logistic regression demonstrated a significant effect on seroconversion for the vaccine dose (P < 0.005) and serum albumin (P = 0.05) but not for the other variables such as race, age, drinking during the study, serum creatinine, arm muscle circumference, and cirrhosis.

CONCLUSIONS

A high- and accelerated-dose regimen of hepatitis B improves the serological response in alcoholic patients. This regimen (currently recommended for hemodialysis patients) should now also be considered for patients with a history of alcoholism.

Prospective analysis of the factors influencing the antibody response to hepatitis B vaccine in hemodialysis patients

Hepatitis B vaccine is effective in producing protection against hepatitis B virus (HBV) infection in hemodialysis (HD) patients, but the antibody response is variable. To identify those factors implicated in the vaccine response, in a prospective study over a 24-month period, we vaccinated 80 seronegative patients on HD (group A) and monitored clinical, biochemical, and immunologic parameters. The protective immunity acquired by vaccination was compared with that developed through HBV infection in 22 age-matched HD patients (group B). The anti-HBs antibody-seronegative patients followed a four-dose vaccination schedule (0, 1, 2, and 6 months) with 40 microg DNA-recombinant hepatitis B vaccine. One month after vaccination, 77.5% of the patients had seroconverted, and 72.5% achieved high antibody response, whereas 22.5% were nonresponders. Patients aged younger than 40 years seroconverted 100%; those aged 40 to 60 years, 75% (P < 0.01); and patients older than 60 years, 74% (P < 0.001). No differences between responders and nonresponders concerning sex, time on HD, HD dose, nutritional status, hemoglobin level, HD membrane, iPTH level, calcitriol treatment, or number of transfusions during vaccination were found. The presence of other factors, such as recombinant human erythropoietin (rHuEPO) therapy or hepatitis C virus (HCV) infection, did not significantly influence antibody responses to hepatitis B immunization. A greater frequency of DR3 (53.8% v 25.7%, P < 0.05), DR7 (53.8% v 18.6%, P < 0.01), and DQ2 (76.9% v 44.1%, P < 0.05), and a lesser frequency of A2 (7.7% v 37.2%, P < 0.05) were found in nonresponders compared with responders. Eighteen months after vaccination, the analysis showed similar antibody titers but lower seroconversion rates in group A as compared with group B. In conclusion, unresponsiveness to hepatitis B vaccine in HD patients was related to factors such as older age, the presence of DR3, DR7, and DQ2, and the absence of A2 alleles. Although the seroprotection produced by the vaccine was less than that achieved through natural HBV infection, our protocol of vaccination was sufficiently immunogenic and provided lasting protection.

Viral hepatitis in children with renal disease

Specific and sensitive diagnostic tests are now available to identify type A, B, C, D and E hepatitis. Hepatitis A and E which cause only acute, very rarely fulminant, hepatitis are spread largely by the faecal-oral route, having a brief viraemic phase. Hepatitis B, C and D which are transmitted parenterally and via secretions are often associated with chronic viraemia. Patients with chronic renal disease are at particular risk. Impaired immunity due to disease or drugs increases the propensity to develop a chronic carrier state which may progress to cirrhosis and hepatocellular carcinoma. Limited reports indicate that hepatitis C infection may cause cirrhosis more rapidly than hepatitis B. The emergence of mutants to both hepatitis B and C is a cause for concern. Treatment with interferon is of limited efficacy. Screening of blood products for viral markers and prudent handling of potentially infected materials to avoid contamination of damaged skin or mucous membrane are the best strategies to prevent infection. Hepatitis B vaccination of all newborns, young adolescents and those at risk is the most effective means of reducing the carrier frequency.

Comparison of two immunization schedules with recombinant hepatitis B vaccine and natural immunity acquired by hepatitis B infection in dialysis patients

In a prospective study over a 2-year period we compared two practical dosage schedules to vaccinate dialysis patients against hepatitis B virus (HBV) infection using a yeast-derived recombinant hepatitis B vaccine (Engerix-B). In addition, the natural history of this acquired immunity was compared with that developed through HBV infection in dialysis patients and healthy subjects. Patients on dialysis treatment (haemo or peritoneal) who were tested to be negative for hepatitis B surface antigen (HBsAg), anti-HBs and anti-HB core were allocated at random to receive HB vaccine according to one of the two schedules. The two groups receiving the vaccine were matched for age, sex, mean duration on dialysis and the form of dialysis treatment received. The group of patients who received a four-dose schedule (at 0, 1, 2 and 6 months) of 40 micrograms of HB vaccine each time (group 2) achieved a seroconversion rate of 79% 1 month after the last dose (at month 7) compared with a seroconversion rate of 55% in those who received three doses (at 0, 1 and 6 months) of 40 micrograms each (group 1). Healthy controls who received half the amount of vaccine on a three-dose schedule (group 3) attained 100% seroconversion (p < 0.05). When retested at 24 months, 30% of seroconverters in group 1 had lost their protective immunity, compared with only 6% in group 2 and 15% in group 3. The magnitude of antibody response (total and anti-(a)-specific) was assessed in the vaccinees at 24 months and compared with that of two other control groups, dialysis patients (group 4) and healthy volunteers (group 5), who had acquired immunity from HBV infection. In general, the total and anti-(a)-specific HBs titres in the dialysis patients (groups 1, 2 and 4) were lower than in their corresponding healthy controls (groups 3 and 5), irrespective of whether the protective immunity was acquired by vaccination or HBV infection. However, the anti-HBs titres in dialysis patients who received four doses were significantly higher than in those who received only three doses (p < 0.05), which indicated a better protective immunity in favour of the former regime. The magnitude of antibody response in the vaccinees of groups 2 and 3 compared well with their respective controls, groups 4 and 5, who had acquired their immunity through HBV infection. This implied that the yeast-derived vaccine was sufficiently immunogenic and provided lasting protection in patients and healthy subjects vaccinated by an appropriate dosage schedule.(ABSTRACT TRUNCATED AT 400 WORDS)

Immunogenicity of a recombinant DNA hepatitis B vaccine in renal transplant patients

In renal transplant patients hepatitis B infection is associated with a higher morbidity and mortality. Therefore, we investigated the immunogenicity of an enhanced vaccination scheme with a recombinant DNA hepatitis B vaccine in renal allograft recipients. Injections of 40 micrograms were given at months 0, 1, 2 and 6. Conversion rate (anti-HBS antibody titre > 10 mIU ml-1) was only 36%. On the other hand, in patients vaccinated before transplantation, a booster injection of 40 micrograms was highly successful, resulting in a rise of antibody titre > 10 mIU ml-1 in 86%. In view of the poor vaccination results after transplantation, we strongly recommend hepatitis B vaccination prior to transplantation.

Influence of vaccination schedules and host factors on antibody response following hepatitis B vaccination

In a prospective multicentre trial, the influence of schedule, compliance, age, sex and weight on the antibody response to hepatitis B vaccination was investigated. Comparison of the vaccination schedules 0, 1, 6 months (group 1; n = 143) and 0, 1, 2, 12 months (group 2; n = 141) was performed in months 3, 7 and 12. In addition, the antibody response was compared one month after the third and one and six months after the last vaccination. Seroprotection rates (anti-HBs greater than 10 IU/l) and antibody titres, given as geometric means (GMTs), were higher in group 1 at month 12 as well as one month after completion of three immunizations. More vaccinees of group 2, however, showed seroprotection at month 3 with higher GMTs. In addition, GMTs in group 2 were higher both one month and six months after the last vaccine dose. Determination of parallel corrected correlation factors demonstrated that age was the most important single factor, followed by body weight and sex. However, no more than 3% of the variation in the GMT can be explained by the influence of age. Due to decreased compliance with the four-dose schedule with a drop-out rate of approximately 10% of the vaccinees, the total percentage of initial vaccinees who in the end developed protective antibody levels was higher in the 0, 1, 6 months schedule. Thus, it can be concluded that subjects likely to comply will benefit from the 0, 1, 2, 12 months schedule as more rapid protection is obtained and the higher antibody levels after the booster vaccination at month 12 provide longer protection. However, vaccinees whose compliance might be questionable over a period of 12 months, should be selected for the vaccination 0, 1, 6 months schedule as compliance is at a higher level over this period and advantage can be taken of the booster effect of the third dose given in month 6.

Therapeutic advances in the prevention of hepatitis B: yeast-derived recombinant hepatitis B vaccines

Viral hepatitis is second to gonorrhea as the most commonly reported infectious disease in the US. Hepatitis B accounts for the majority of viral hepatitis cases. Fortunately, the disease is self-limiting and frequently resolves completely with minimal complications; however, a significant number of individuals may experience long-term sequelae. Research utilizing genetic engineering has led to the development of yeast-derived recombinant DNA (YDR) hepatitis vaccines--a significant advancement in the control and prevention of hepatitis B. The recombinant process allows production of unlimited quantities of vaccine at considerably lower cost and without the potential threat of blood-borne illness. Clinical trials in various high-risk populations have demonstrated the effectiveness and safety of YDR vaccines. However, questions regarding optimal regimen and the need for periodic revaccination remain unanswered. Persons at risk should be adequately vaccinated against hepatitis B.

Hepatitis 1990

In recent months newer concepts have evolved in our understanding of infection with the viruses that cause acute viral hepatitis. The natural course of hepatitis A has been described, and reliable diagnostics for its identification are now available. The early development of serologic assays for hepatitis B virus infection resulted in a rapid expansion of our knowledge of the serologic identification of this virus and of the natural course of the agent. Improved serologic tests have shown that infection with the virus is far more common than was appreciated in previous years. Its association with the development of chronic liver disease in up to 10% of infected patients is well documented. Among the most exciting events in our understanding of viral hepatitis has been the development of an assay to detect antibody to hepatitis C virus. This has enabled us to determine that posttransfusion hepatitis is usually due to a single hepatitis C viral agent. Unfortunately, the available antibody assay is associated with a high degree of false positivity and requires the utilization of a secondary test for specificity or a naturalization test to identify true positives. It is clear, however, that a person who has this antibody and who is also positive for a secondary test for specificity is likely to harbor an infectious agent in his or her blood. Hepatitis C is associated with an unusually high degree of chronicity, exceeding 50% in many studies. Second-generation assays have already been developed, and it is likely that we will shortly see a great expansion of our serologic diagnostic capabilities.(ABSTRACT TRUNCATED AT 250 WORDS)