Effects of oral levamisole as an adjuvant to hepatitis B vaccine in adults with end-stage renal disease: a meta-analysis of controlled clinical trials. Clin Ther. 2010;32:1-10. [PMID: 20171406 DOI: 10.1016/j.clinthera.2010.01.005]

Effectiveness of oral levamisole as an adjuvant to hepatitis B vaccination in healthcare workers non-responsive to previous vaccination: A randomized controlled trial

Background

Healthcare workers are at risk for HBV infection through percutaneous or mucosal contact with infected blood, body secretions, or blood products or via sharps injury. Hepatitis B vaccination, despite immunogenicity, may not induce a proper immune response in 5-10% of the general adult population. Increased immune response in healthcare providers that do not respond properly to conventional hepatitis B vaccination is an important health challenge. Therefore, the aim of the present study was to evaluate the effectiveness of hepatitis B vaccination plus oral levamisole as adjuvant in healthcare providers non-responsive to routine vaccination.

Materials and methods

The healthcare workers that were non-responsive to previous hepatitis B vaccination were enrolled in a double-blind randomized placebo-controlled clinical trial. The participants were then randomized to two groups including hepatitis B vaccination (as a three-dose series on a 0, 1, and 2-month schedule in the deltoid muscle) plus levamisole (levamisole group) and hepatitis B vaccination plus placebo (placebo group) at a 1:1 ratio. The outcome measure was the HBs antibody titer one month after receiving each dose as well as the seroprotection ratio. The side effects were also evaluated in all participants.

Results

In total, 22 subjects finished the trial (11 individual in per group). The median antibody titer one month after receiving the first and third doses increased more in the levamisole group compared to the placebo group but the difference was not significant (p ​= ​0.34, p ​= ​0.66, respectively).The seroprotection ratio after three doses was similarly high in both groups (90.9% in per group). Furthermore, the seroprotection ratio and median antibody titer had no significant correlation with age, sex, BMI, and history of smoking in intervention and control groups (p>0.05). No serious side effects were noted in both groups.

Conclusions

Re-vaccination can boost the immune response in healthcare professionals that were non-responsive to previous vaccination although the mean antibody titer was higher in the levamisole group.

Levamisole Therapy in COVID-19

Coronavirus disease 2019 (COVID-19) a global infectious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2) affects various organs, primarily the respiratory system, and presented with pulmonary manifestations such as acute lung injury (ALI) and acute respiratory distress syndrome. Levamisole (LVM) is an anthelminthic drug; it has immune-modulating effects through induction of type 1 immune response. Based on these findings several recent studies highlighted that LVM might be effective in preventing and treating SARS-CoV-2 infections. The aim of this report is to illustrate the potential role of LVM in SARS-CoV-2 infection and in the management of COVID-19. Different studies proposed that LVM may inhibit proliferation of SARS-CoV-2 through inhibition of papain-like protease. LVM may prevent ALI and acute kidney injury through activation of glucocorticoid receptors. In general, LVM has strong immune stimulant effects by modulating cellular and humoral immune responses. This effect is beneficial in the early phase of COVID-19 and harmful in the late phase. In the early phase, immune stimulation facilitates SARS-CoV-2 clearance and tissue repair, however, in the late phase, immune stimulation in COVID-19 may increase propagation risk of cytokine storm. In conclusion, LVM therapy in COVID-19 has bidirectional effects, beneficial in the early phase and harmful effects in the late phase of COVID-19. Clinical trial and prospective studies are warranted in this regard to confirm the efficacy and timing administration of LVM in the management of COVID-19.

The Model of "Informed Refusal" for Vaccination: How to Fight against Anti-Vaccinationist Misinformation without Disregarding the Principle of Self-Determination

Vaccines are arguably a public health success story as well as an incredibly cost-effective medical resource. Despite this, worldwide concerns about their safety are growing, with the risk of increased morbidity and mortality in vaccine-preventable diseases because of vaccine refusal. The global political trend in developed countries is to increasingly reduce mandates and the compulsory nature of vaccination programs. This is due to strong opposition from anti-vaccination movements and groups. While these have existed since the beginnings of vaccinology, they have recently gained a strong foothold through massive exploitation of the media and especially the internet. This has led to widespread misinformation and greater difficulty for governments and health institutions in dealing with parents’ concerns and misconceptions. Common strategies in order to maintain a high degree of public acceptance of vaccines include the enhancement of adverse effect reporting systems, the enrichment of scientific literature, and the dissemination of targeted information to parents and health care providers. Vaccine risk perception, in fact, largely exceeds the evidence and is linked to well-known general population cognitive bias, which must be recognized and corrected. Although there is no doubt about the convenience of universal vaccination, a lively international debate is underway with regard to the legitimacy of mandatory vaccination programs. Most scientists agree that the individual’s right to self-determination should be preserved. The only way to simultaneously protect the right to health is to introduce an informed refusal model, which aims to guarantee the highest coverage rates for vaccination.

Comparative analysis of the safety and efficacy of HBsAg-1018 versus HBsAg-Eng: a meta-analysis

INTRODUCTION

In addition to alum adjuvant, a wide diversity of adjuvants have been developed to enhance immune response of hepatitis B virus (HBV) vaccine in varying subjects, either in healthy vaccinators or subjects with hypo-immunity. In this context, a novel HBV vaccine HBsAg-1018, formulated with a toll-like receptor 9 agonist, was developed, and is currently in the phase of clinical trials. So, the first meta-analysis was performed to examine the safety and immune response of HBsAg-1018 among varying subjects.

MATERIAL AND METHODS

On the basis of inclusion criterion, eligible studies that reported safety and immunogenicity induced by HBsAg-1018 vaccination in randomised, controlled trials (RCTs) were involved from three databases: PubMed, EMBASE, and the Cochrane Library, and further confirmed by two reviewers. Meta-analysis was conducted using RevMan 5.3. The pooled relative risk (RR) for safety and immunogenicity was calculated using random-effects or fixed-effects models according to the heterogeneity of included studies. The methodology quality of eligible studies was assessed using the Cochrane Handbook for Systematic Reviews of Interventions version 5.1.0.

RESULTS

In total 5073 subjects administrated with HBV vaccine from four eligible publications were included in this meta-analysis. The data related to immunogenicity and safety post vaccination were pooled for meta-analysis. For safety, the combined RRs for adverse reactions were 0.98 (95% CI: 0.89-1.08), 1.02 (95% CI: 0.94-1.10) for AE, 0.88 (95% CI: 0.70-1.10) for SAE, and 1.07 (0.12-9.17) for death. No statistical heterogeneity among RCTs was found (p > 0.05). For immunogenicity, at four weeks post vaccination, seroprotection rates (SPRs) in HBsAg-1018 were significantly superior to the conventional HBV vaccine containing alum adjuvant, HBsAg-Eng (Engerix-B®, GlaxoSmithKline, Rixensart, Belgium) (RR: 4.35; 95% CI: 3.35-5.65). Furthermore, superior immunogenicity of HBsAg-1018 was maintained with RRs up to 1.23 and 95% CI: 1.20-1.27 through 28 weeks post vaccination. However, there was considerable heterogeneity with > 80% I2 value (p < 0.05).

CONCLUSIONS

In comparison with HBsAg-Eng, HBsAg-1018 exhibited superior immune response and comparable safety profile with HBsAg-Eng in varying subjects. HBsAg-1018 is an effective and safe prophylactic measure to prevent HBV infection.

Hepatitis B vaccine nonresponders: Possible mechanisms and solutions

OBJECTIVE

Hepatitis B (HBV) is a viral illness that chronically infects 240 million people worldwide, leads to liver disease, and increases risk of hepatocellular carcinoma. The HBV vaccine has decreased HBV infection, and it and the human papilloma virus vaccine are the only vaccines that prevent cancer. Despite the effectiveness of the HBV vaccine, some populations do not develop protective responses. The risk groups for poor response include those with immunosuppression or dialysis-dependent, end-stage renal disease. Five percent of normal people do not have a response. These subjects are deemed HBV "nonresponders." Multiple strategies to improve the immunogenicity of the HBV vaccine are currently being pursued, including vaccine adjuvants, recombinant vaccines, and immune enhancement via up-regulation of dendritic cells.

DATA SOURCES

PubMed was searched for peer-reviewed publications published from January 1980 to September 2017.

STUDY SELECTIONS

Studies retrieved for inclusion summarized potential mechanisms behind HBV vaccine nonresponsiveness and potential solutions.

RESULTS

The mechanisms behind HBV vaccine nonresponsiveness vary between each subject population. Many current and future strategies may provide protective immunity against HBV in each of these populations.

CONCLUSION

This review provides a background on the immunology of HBV infection, the possible immunologic mechanisms to explain HBV vaccine nonresponsiveness, current research aimed at improving vaccine effectiveness, and possible future approaches for providing nonresponders protection from HBV.

Dendritic Cell Dysfunction in Patients with End-stage Renal Disease

End-stage renal disease (ESRD) with immune disorder involves complex interactions between the innate and adaptive immune responses. ESRD is associated with various alterations in immune function such as a reduction in polymorphonuclear leukocyte bactericidal activity, a suppression of lymphocyte proliferative response to stimuli, and a malfunction of cell-mediated immunity at the molecular level. ESRD also increases patients' propensity for infections and malignancies as well as causing a diminished response to vaccination. Several factors influence the immunodeficiency in patients with ESRD, including uremic toxins, malnutrition, chronic inflammation, and the therapeutic dialysis modality. The alteration of T-cell function in ESRD has been considered to be a major factor underlying the impaired adaptive cellular immunity in these patients. However, cumulative evidence has suggested that the immune defect in ESRD can be caused by an Ag-presenting dendritic cell (DC) dysfunction in addition to a T-cell defect. It has been reported that ESRD has a deleterious effect on DCs both in terms of their number and function, although the precise mechanism by which DC function becomes altered in these patients is unclear. In this review, we discuss the effects of ESRD on the number and function of DCs and propose a possible molecular mechanism for DC dysfunction. We also address therapeutic approaches to improve immune function by optimally activating DCs in patients with ESRD.

Unsolved problems and future perspectives of hepatitis B virus vaccination

Hepatitis B virus (HBV) infection is still a serious worldwide problem, and vaccination is the most effective strategy for primary prevention of the infection. Although universal vaccination may be required for total eradication, several countries, including Japan, have not yet adopted universal vaccination programs. Some individuals are non-responders to HBV vaccine and several mechanisms responsible for their poor response have been proposed. To overcome non-response, third generation vaccines with pre-S proteins have been developed. These vaccines have shown better anti-HBs responses and may also be effective in preventing infection by HBV with S mutant. Improvement of vaccine efficacy by intradermal administration, or co-administration with cytokines or adjuvants, may also be effective in non-responders. The necessity, timing and method of booster vaccination in responders with decreased anti-HBs responses, and effective vaccination against S-mutant HBV, are issues requiring resolution in the global prevention of HBV infection.

Effect of levamisole supplementation on tetanus vaccination response rates in haemodialysis patients: a randomized double-blind placebo-controlled trial

Levamisole as an immunomodulator drug has been demonstrated to improve the immune response to hepatitis B virus vaccination in haemodialysis patients. The aim of this randomized double-blind placebo-controlled trial was to evaluate the effect of levamisole supplementation on tetanus-diphtheria (Td) vaccine response rates in haemodialysis patients. Forty haemodialysis patients who had not received tetanus vaccination in a year before investigation and had unprotective anti-tetanus immunoglobulin G (IgG) levels (<0.1 international unit/mL) were enrolled and randomized into two equal groups to receive one dose of intramuscular Td vaccine supplemented with either levamisole (100 mg) or placebo daily, for 6 days before and 6 days after vaccination. The anti-tetanus IgG levels were measured 1 and 6 months after vaccination. One month post-vaccination, four patients were excluded from the levamisole group and two from the placebo group because of either death or renal transplantation. At 1 month, 13 out of 16 (81%) patients in the levamisole group as compared with six out of 18 (33%) patients in the placebo group developed protective anti-tetanus IgG levels (relative risk = 2.44, 95% confidence interval (CI) = 1.21, 4.88). From 1 to 6 months post-vaccination, one more patient in the levamisole group and two more patients in the placebo group were excluded because of renal transplantation. At 6 months, 11 out of 15 (73%) patients in the levamisole group as compared with four out of 16 (25%) patients in the placebo group still had protective anti-tetanus IgG levels (relative risk = 2.93, 95% CI = 1.19, 7.23). Supplementation of Td vaccination with levamisole may enhance seroconversion against tetanus in haemodialysis patients.

Hemodialysis and hepatitis B vaccination: a challenge to physicians

Hepatitis B is responsible for the development of half of hepatocellular carcinoma cases and is a major cause of hepatic insufficiency. The vaccine against hepatitis B virus does not exhibit the same high efficacy in patients on hemodialysis as it does in immunocompetent individuals. The medical literature recommends vaccination with four doses (40 mg each) of the hepatitis B virus vaccine before beginning hemodialysis; however, approximately one-third of hemodialysis patients do not respond to this vaccination schedule. A new serologic test should be performed each year for individuals who respond adequately, whereas a booster dose should be offered to those with antibody titers below 10 mIU/mL. In this study, we followed 83 hemodialysis patients and collected quantitative serologic measurements every 2 months over a 1-year period. We made the measurements 1 month after the vaccination period. We found that 41% of the patients had antibody titers below 10 mIU/mL (nonresponders), 21.7% had antibody titers between 10 mIU/mL and 100 mIU/mL (poor responders), and 37.3% had antibody titers higher than 100 mIU/mL (good responders). Patients with diabetes and/or hypertension exhibited worse response to vaccination. All subjects displayed decreasing antibody titers during the observation period. The group of poorly responsive patients had antibody titers below 10 mIU/mL at the 6-month follow-up period.

Vaccination issues in patients with chronic kidney disease

Infections are an important cause of morbidity and mortality among patients at all stages of chronic kidney disease. Prevention through vaccination remains the best strategy to minimize the adverse consequences associated with these infectious diseases in this, and all, populations. Unfortunately, patients with chronic kidney disease demonstrate inadequacies of specific immune-cell function that are required for generating a protective vaccine response. Nevertheless, early vaccination of this high-risk population has demonstrated good clinical outcomes during progression to late-stage disease. We review the available evidence linking immune impairment in adult patients with late-stage chronic kidney disease to diminished vaccine responses. We highlight the importance of early vaccination in disease with high risk for development of CKD and novel vaccine approaches in development that may help to address improvement in protective boosting of immunity during late-stage disease.

Levamisole usage as an adjuvant to hepatitis B vaccine in hemodialysis patients, yes or no?

BACKGROUND

Hepatitis B virus (HBV) infection is much more common in hemodialysis patients than the general population. These patients have an impaired immune response to HBV vaccination; to that end there are certain studies that have evaluated levamisole as an immunomodulator agent improving HBV vaccination response rate in hemodialysis patients.

OBJECTIVES

In the current review, we have assembled all of the results to determine whether lavamisole is of value as an adjuvant to HBV vaccination in hemodialysis patients.

MATERIALS AND METHODS

Science Direct (Elsevier), ProQuest, Springer, MD Consult, BMJ Journals, Pubmed and Wiley were searched for levamisole application to HBV vaccination in hemodialysis patients. All studies revealed a seroconversion response level between levamisole plus HBV vaccine versus HBV vaccine alone.

RESULTS

From 10 relevant studies, 5 studies fulfilled our inclusion criteria. Three of them suggested the significant benefit of adding levamisole to the HBV vaccine to increase augment seroprotection level in hemodialysis patients. Another study reported a decrease in seroprotection level and another study showed no significant difference caused by levamisole administration.

CONCLUSIONS

Due to the limited number of studies evaluated, it is challenging to perform a definite decision about routinely administering levamisole in addition to the HBV vaccine for all hemodialysis patients. However, it does seem reasonable to recommend administration of levamisole for impaired immune response patients.

Effects of Oral Levamisole as an Adjuvant to Hepatitis B Vaccine in HIV/ AIDS Patients: A Randomized Controlled Trial

BACKGROUND

Human immunodeficiency virus (HIV) infected patients are also frequently exposed to the hepatitis B virus (HBV), due to the common routes of transmission, therefore, prevention of hepatitis B results in decreased complications of the disease.

OBJECTIVES

Since the immune response of HIV patients to hepatitis B vaccination is less robust than that found in healthy individuals, this study aimed to evaluate the effect of a levamisole adjuvant on increasing the immune response.

PATIENTS AND METHODS

In this study, 89 HIV infected patients, without a history of HBV infection or vaccination, were randomly allocated into experimental (44 patients) and control (45 patients) groups. HBV vaccination was performed using the Hepavax-Gene TF vaccine, 40 μg three times at intervals of; zero, one, and three months. Levamisole 50 mg twice a day or a placebo, was administered to the experimental and control groups, respectively, for a period of six days before to six days after the vaccination. Immune response was evaluated by measuring hepatitis B surface antibodies (HBsAb) concurrently with the second and third vaccine administration, and at one and three months at the conclusion of the vaccination program.

RESULTS

The immune response following the threevaccinations was higher in those who were receiving levamisole compared with the controls (90% vs. 65.38%) (P = 0.05). Furthermore, the immune response and the mean antibody titer following the repeated vaccination in the experimental group showed a higher increase than in the control group. The immune response and the mean titer of antibody were not associated with; age, sex, body mass index, history of smoking and/or intravenous drug use in either of the groups. However, regarding CD4+ cells more than 200 cell/mm3, mean antibody production significantly increased in both groups.

CONCLUSIONS

Using levamisole with the hepatitis B vaccination can increase the immune response and antibody titer mean in HIV infected patients. Since these patients have a more complete response with CD4+ cells more than 200 cell/mm3, vaccination and effective adjuvants seem to be most beneficial when CD4+ cells are greater than 200 cell/mm3, in HIV infected patients.

Improving hepatitis B vaccine efficacy in end-stage renal diseases patients and role of adjuvants

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.

Systematic identification of small molecule adjuvants

INTRODUCTION

Adjuvants potentiate immune responses, reducing the amount and dosing frequency of antigen required for inducing protective immunity. Adjuvants are of special importance when considering subunit, epitope-based or more unusual vaccine formulations lacking significant innate immunogenicity. While numerous adjuvants are known, only a few are licensed for human use; principally alum, and squalene-based oil-in-water adjuvants. Alum, the most commonly used, is suboptimal. There are many varieties of adjuvant: proteins, oligonucleotides, drug-like small molecules and liposome-based delivery systems with intrinsic adjuvant activity being perhaps the most prominent.

AREAS COVERED

This article focuses on small molecules acting as adjuvants, with the author reviewing their current status while highlighting their potential for systematic discovery and rational optimisation. Known small molecule adjuvants (SMAs) can be synthetically complex natural products, small oligonucleotides or drug-like synthetic molecules. The author provides examples of each class, discussing adjuvant mechanisms relevant to SMAs, and exploring the high-throughput discovery of SMAs.

EXPERT OPINION

SMAs, particularly synthetic drug-like adjuvants, are amenable to the plethora of drug-discovery techniques able to optimise the properties of biologically active small molecules. These range from laborious synthetic modifications to modern, rational, effort-efficient computational approaches, such as QSAR and structure-based drug design. In principal, any property or characteristic can thus be designed in or out of compounds, allowing us to tailor SMAs to specific biological functions, such as targeting specific cells or pathways, in turn affording the power to tailor SMAs to better address different diseases.

Immune responses induced by heterologous boosting of recombinant bacillus Calmette-Guerin with Ag85B-ESAT6 fusion protein in levamisole-based adjuvant

In the present study, we evaluated the effectiveness of a levamisole-based adjuvant (ADL) to enhance the ability of the Ag85B-ESAT6 fusion protein to boost immune responses after primary vaccination with recombinant bacillus Calmette-Guerin (rBCG) in Balb/c mice. The results were compared with that of the control adjuvant formulation of dimethyl dioctadecylammonium bromide (DDA) and monophosphoryl lipid A (MPL), which has previously been shown to induce T-helper type 1 (Th1)-biased responses. Enzyme-linked immunospot (ELISPOT) assay with Ag85B and ESAT6 derived peptides corresponding to CD4+ and CD8+ T cell restricted epitopes and cell surface immunostaining indicated that Ag85B-ESAT6/ADL predominantly triggered activation of CD4+ T cells. Functional CD8+ T cells with interferon (IFN)-γ production or cytotoxicity were undetectable all vaccinated mice. The ADL adjuvant modified T-helper (Th) subtypes by up-regulating multiple signature cytokines. Furthermore, profiles of the immunoglobulin G (IgG) subtypes indicated ADL enhanced the secretion of Th1-associated IgG2a antibodies and decreased the yield of Th2-associated IgG1 subtype. These observations suggest that the ADL adjuvant formulated with a protein booster may induce Th1-biased cellular and humoral immune responses to primary vaccination with a live attenuated bacterial TB vaccine.

Intradermal vs intramuscular vaccine against hepatitis B infection in dialysis patients: a meta-analysis of randomized trials

Chronic dialysis patients are at risk of contracting hepatitis B virus infection and have a diminished immune response to hepatitis B virus vaccine. Recent reports support intradermal administration of hepatitis B virus vaccine in patients on regular dialysis but the efficacy and safety of this approach remain unclear. We conducted a meta-analysis of randomized, controlled clinical trials to compare seroprotection achieved by intradermal vs intramuscular hepatitis B vaccine, in patients on maintenance dialysis. Meta-analysis of data from 718 adults (14 trials) on long-term dialysis demonstrated that intramuscular hepatitis B vaccination was less likely to achieve seroprotection than intradermal vaccination, the pooled odds ratio was 0.454 (95% CI, 0.3; 0.67), P = 0.001. The test of study heterogeneity was not significant. This difference did not persist during follow-up (6-60 months after completing vaccine schedule), the pooled odds ratio being 0.718 (95% CI, 0.36; 1.47), NS. Some evidence of significant heterogeneity including publication bias was present but stratified analysis in various subgroups showed that this issue did not meaningfully change our results. Intradermal hepatitis B vaccine was safe and well tolerated. We conclude that intradermal hepatitis B vaccine induces a superior response rate compared to intramuscular route at completion of vaccine cycle, despite a lower vaccine dose. No significant advantage was found over longer follow-up. It remains unclear whether the higher seroprotection rate achieved with intradermal route translates into a lower frequency of de novo hepatitis B among patients on maintenance dialysis.

Effect of high-flux hemodialysis on delayed hepatitis B virus vaccination response in hemodialysis patients

OBJECTIVES

The aim of the study was to evaluate the effect of high-flux (HF) hemodialysis (HD) on delayed protective hepatitis B virus (HBV) antibody seroconversion in HD patients who had no response to the classic third dose of HBV vaccination.

METHODS

We performed a prospective cohort study. Forty-two patients who did not respond within 6 months after the third dose of the vaccination were enrolled in the study. The patients were randomized to either an HF HD treatment group (n =19) or a conventional HD treatment group (n = 23). Patients' serum hepatitis B surface antibody levels were followed monthly.

RESULTS

After 6 months of follow-up, there were 15 (78.9%) patients in HF group and 7 (30.4%) patients in the control group showing delayed HBV vaccination response. The level of antibody titer of HBV vaccination responders was 103.6 ± 48.3 mIU/mL in the HF group and 23.5 ± 15.7 mIU/mL in the control group. The antibody titer did not correlate with sex, age, serum albumin, or hemoglobin in either group. Four patients in control group lost HBV vaccination response > 2 times after 3 months of follow-up, whereas no patients in the HF group lost HBV vaccination response.

CONCLUSION

Hemodialysis patients who do not respond to the classic third dose of HBV vaccination could reobtain a delayed higher protective HBV antibody seroconversion rate by HF HD without other intervention.