Boosters for hepatitis B vaccination? Need for an evidence-based policy

Vaccination Campaign against Hepatitis B Virus in Italy: A History of Successful Achievements

In Italy, the vaccination campaign against hepatitis B virus has been characterized by two phases. In the first phase (1984-1991), vaccination with plasma-derived vaccines was first recommended for the high-risk group. In the second phase (1991-nowadays), recombinant vaccine targeted, by law, infants 2 months old and teenagers 12 years old (limited to the first 12 years of campaign); screening for HBsAg became compulsory for all pregnant women during the third trimester of pregnancy. Successful achievements have been attained: No acute HBV case has been observed in the age group targeted by vaccination, the pool of chronic HBsAg carriers is strongly reduced, perinatal HBV transmission is under control, and acute delta virus hepatitis cases are nearly eliminated. The key point of this success has been the peculiar vaccination policy adopted. The combined vaccination of teenagers has generated an early immune cohort of youths, who are no longer at risk of acquiring HBV infection by sources of exposure (i.e., drug use and unsafe sex practices) typical of the young adults. Vaccination of household contacts with HBsAg-positive subjects represents an area of improvement; providing migrants and refugees access to healthcare services is also a focal point. In 2020, Italy became the first country in Europe to achieve the WHO's regional hepatitis targets.

Hepatitis B Vaccination: A Historical Overview with a Focus on the Italian Achievements

Vaccination is the most effective way to control and prevent acute and chronic hepatitis B, including cirrhosis and HCC, on a global scale. According to WHO recommendations, 190 countries in the world have introduced hepatitis B vaccination into their national childhood immunization programs with an excellent profile of safety, immunogenicity, and effectiveness. Following vaccination, seroprotection rates are close to 100% in healthy children and over 95% in healthy adults. Persistence of anti-HBs is related to the antibody peak achieved after vaccination. The peak is higher the longer the antibody duration is. Loss of anti-HBs does not necessarily mean loss of immunity since most vaccinated individuals retain immune memory for HBsAg and rapidly develop strong anamnestic responses when boosted. Evidence indicates that the duration of protection can persist for at least 35 years after priming. Hence, booster doses of vaccines are currently not recommended to sustain long-term immunity in healthy vaccinated individuals. In Italy, vaccination against hepatitis B is met with success. In 2020, Italy became one of the first countries in Europe to be validated for achieving the WHO regional hepatitis B control targets.

Acute hepatitis B virus infection despite vaccination in a patient treated by infliximab: a case report

Background

Despite an effective vaccine, hepatitis B remains a major global health problem due to its significant morbidity and mortality. Vaccination in immunosuppressed patients such as those treated for an inflammatory bowel disease (IBD) can be less effective. This case describes an uncommon original diagnosis of an acute hepatitis B infection occurring in a vaccinated but immunocompromised IBD patient under long-term infliximab treatment. A low anti-HBs titer and the presence of HBsAg escape mutations are possible hypotheses to explain this unexpected infection.

Case presentation

A 28-year-old Caucasian male, regularly followed-up for a Crohn’s disease treated by infliximab, was regularly screened for sexually transmissible infections because of at-risk behaviors. Despite a correct immunization scheme against hepatitis B virus (HBV), an active HBV infection was diagnosed during one of those screenings. Retrospective testing of a sample collected 6 months earlier was in favor of an evolution from an acute hepatitis B toward a chronic hepatitis B. The patient has always had a low anti-HBs antibody levels (near the threshold of 10 IU/L) possibly explaining his infection. In addition, HBV sequencing revealed a genotype A2 HBV strain, carrying the sD144A substitution on the S protein, known as a potential immune escape variant. Dual therapy combining tenofovir disoproxil fumarate and emtricitabine, active against HBV but also efficient as an HIV pre-exposure prophylaxis, was initiated. Ten months after treatment initiation, all surrogate biochemical and virological endpoints for HBV functional cure were achieved. Treatment and periodical monitoring are being maintained.

Conclusion

Emphasis should be placed on HBV screening, vaccination and regular monitoring of patients under long-term immunosuppressive therapy, particularly those with at-risk behaviors.

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.

Discordance of hepatitis B vaccination policies for healthcare workers between the USA, the UK, and Germany

The hepatitis B (HB) vaccine is effective for the prevention of HB virus infection. It has been widely accepted that an anti-HB surface antibody (HBs) level ≥10 mIU/mL is protective against HB virus infection. Although transient infection can occur in individuals who attain a peak level of anti-HBs ≥10 mIU/mL after primary vaccination, long-term follow-up studies show that successful primary vaccination can prevent individuals from acute clinical hepatitis and chronic infection. Healthcare workers (HCWs) are at-risk individuals. Based on the accumulated data, the USA considers an anti-HBs level ≥10 mIU/mL to constitute successful vaccination for HCWs. In contrast, because some anti-HBs assays cannot accurately measure in the low anti-HBs range, including 10 mIU/mL, the UK and Germany consider an anti-HBs level ≥100 mIU/mL to constitute successful vaccination for HCWs. In the USA and UK, a booster dose is unnecessary for HCWs after successful vaccination. In Germany, anti-HBs testing is recommended for HCWs who are at particularly high individual exposure risk 10 years after successful primary immunization, and a booster dose is offered if the anti-HBs level has declined to ˂100 mIU/mL. The differences in the goal of HB vaccination, reliability of anti-HBs assays, and use of booster vaccination cause discordance in HB vaccination policies for HCWs.

Revaccination against hepatitis B in late teenagers who received vaccination during infancy: Yes or no?

The significance of vaccination against hepatitis B during infancy is recognized worldwide, however, whether booster or revaccination after a period of time following the primary vaccination is required remains controversial. Recently, cross-sectional epidemiological surveys found that HBsAg prevalence in subjects born after the implementation of mass vaccination was increased with age, which was attributed to waning of anti-HBs over time. However, comprehensive analysis of the closely related cross-sectional surveys showed that the age-specific increased HBsAg prevalence was more likely associated with the carry-over of the infection occurred in early life, likely due to imperfect coverage of hepatitis B vaccination at the beginning of its introduction. Latest studies showed that booster response could be observed in the majority of individuals vaccinated 30 years ago. Moreover, confirmed breakthrough HBV infection with severe consequences in successfully vaccinated individuals is extremely rare. Thus far no compelling evidence has been acquired to support booster vaccination in adolescence. The uncertainty regarding the duration of protection of hepatitis B vaccination, especially beyond 30 years after the primary vaccination, merits a systematically designed study to follow the same cohort of participants longitudinally, which differs from the cross-sectional studies reported previously, can hopefully offer more direct evidence to help us to determine whether revaccination of hepatitis B vaccine is necessary.

Prevention of hepatitis B

Hepatitis B virus (HBV) causes life-threatening liver disease. It is transmitted through a horizontal route or a mother-to-infant route, and the latter is the major route in endemic areas. Prevention of HBV infection by immunization is the best way to eliminate HBV-related diseases. The HBV vaccine is the first human vaccine using a viral antigen from infected persons, which is safe and effective. Either passive immunization by hepatitis B immunoglobulin (HBIG) or active immunization by HBV vaccine is effective, and a combination of both yields the best efficacy in preventing HBV infection. The impact of universal HBV immunization is huge, with 90%-95% effectiveness in preventing chronic HBV infection. It is the first cancer preventive vaccine with a protective efficacy against hepatocellular carcinoma (HCC) of ∼ 70%. Nevertheless, further effort is still needed to avoid vaccine failure and to increase the global coverage rate.

Approach and management of patients with chronic hepatitis B and C during the course of inflammatory bowel disease

Inflammatory bowel disease and chronic viral hepatitis are 2 distinct but common conditions throughout the world. Mostly, both need life-long follow-up. Since immunosuppressive drugs remain corner stones of inflammatory bowel disease management, one should be aware of the concomitant presence of chronic viral hepatitis in such patients to prevent serious (even fatal) outcomes. Recently, new treatment options have become available in the treatment of both inflammatory bowel disease and chronic viral hepatitis. In this review, we have discussed and summarized current treatment and follow-up strategies for those 2 important public health issues in light of available literature.

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.

Efficacy of the vaccination in inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with conditions that may predispose to infections, such as the lack of an appropriate innate immune response to infectious agents, malnutrition, surgery, and immunosuppressive and biological drugs. Some of these infections may be preventable by vaccination. Therefore, for this particular patient population, the benefits of implementing a well-established immunization protocol in daily clinical practice are potentially even greater than for the general population. In recent years international consensus guidelines have been published, but in spite of theses recommendations, studies have shown that a significant number of patients with IBD remain inadequately immunized. Another important issue regarding immunization in this population is that vaccine efficacy among patients receiving immunosuppressive therapies has been variable. In a healthy population, a humoral immune response to hepatitis B vaccination (HBV) is expected in > 90%, whereas a much lower rate is achieved in the IBD patients. Immunosuppressive, anti-tumor necrosis factor therapy and disease activity have been implicated in the impaired efficacy of the vaccination. The serological response to HBV should be confirmed and patients with an inadequate response should receive a second full series of vaccine. Modified dosing regimens, including doubling the standard antigen dose, might increase the effectiveness. Response to influenza, pneumococcal and tetanus immunization is still not clear, as there are studies that show a normal response to the vaccination while others demonstrate a lack of efficacy. We pose a series of questions on the efficacy of the different vaccinations recommended for IBD patients and attempt to answer them using scientific evidence.

Kinetics of anti-hepatitis B surface antigen titers after hepatitis B vaccination in patients with inflammatory bowel disease

BACKGROUND

Clinically significant hepatitis B (HB) virus infection has been documented among immunocompromised patients who do not maintain anti-hepatitis surface antigen (anti-HBs) concentrations ≥ 10 IU/L after an adequate response to the vaccine. The aims of the study were to understand the kinetics of anti-HBs titers over time in patients with inflammatory bowel disease (IBD) who initially responded to vaccination and to identify factors predictive of losing protective anti-HBs titers.

METHODS

Patients with IBD with a response (anti-HBs > 10 IU/L at 1-3 months) to HB virus vaccination were prospectively included. Anti-HBs titers were measured at 6 and 12 months. Anti-HBs titers were considered negative if they were <10 IU/L at any time during the follow-up. The kinetics of anti-HBs titers in the long term was estimated using Kaplan-Meier curves. Cox regression analysis was performed to identify the factors predictive of losing protective anti-HBs titers.

RESULTS

The sample comprised 100 patients (mean age, 42 years; 68% Crohn's disease; 49% on thiopurines; and 14% on anti-tumor necrosis factors during follow-up). The cumulative incidence of loss of anti-HBs titers was 2% after 6 months and 15% after 12 months. The incidence rate of loss of protective anti-HBs titers was 18% per patient-year. Baseline (after vaccination) anti-HBs titers were lower among patients whose titers became negative during the follow-up than among those who maintained them >10 IU/L (191 versus 515 IU/L; P < 0.001). Treatment with anti-TNFs was the only factor associated with a higher risk of loss of anti-HBs (hazard ratio = 3.1; 95% confidence interval = 1.1-8.8; P = 0.03).

CONCLUSIONS

A high proportion of patients with IBD with protective anti-HBs titers after vaccination lose them over time (18% per patient-year of follow-up). The risk of losing protective anti-HBs titers is 3-fold higher among patients on anti- tumor necrosis factors therapy.

Changes in hepatitis A and B vaccination rates in adult patients with chronic liver diseases and diabetes in the U.S. population

Professional societies recommend hepatitis A and hepatitis B immunization for individuals with chronic liver disease (CLD), but the degree of implementation is unknown. Data were obtained from the National Health and Nutrition Examination Surveys (NHANES) conducted in 1999-2008. For the entire study population and for those with CLD and diabetes, we determined the rates and independent predictors of history of hepatitis A and hepatitis B (HepA and HepB) vaccinations, of their effectiveness, and of seroprevalence of hepatitis A antibody and anti-HB surface antibody. In total, 24,871 participants from NHANES were included: 14,886 (1999-2004) and 9,985 (2005-2008). Of these individuals, 14.0% had CLD and 8.6% had diabetes. During the study period, HepA vaccination in CLD increased from 13.3% ± 1.0% to 20.0% ± 1.5%, HepB vaccination increased from 23.4% ± 1.2% to 32.1% ± 1.5%. Of subtypes of CLD, HepA vaccination rates increased only in nonalcoholic fatty liver disease (NAFLD), whereas HepB vaccination increased for patients with hepatitis C and nonalcoholic fatty liver disease. In the diabetic cohort, HepA vaccination rates increased from 9.3% ± 1.1% to 15.4% ± 1.7% and HepB rates increased from 15.2% ± 1.5% to 22.4% ± 1.7%. All changes were similar to those observed in the general population. The quality measure (QM) for HepA in the general population decreased from 44.4% ± 1.2% in 1999-2004 to 41.7% ± 1.9% in 2005-2008, and similar changes were noted for all subcohorts. On the other hand, QM for HepB increased from 31.7% ± 0.9% to 40.7% ± 1.0% in the population, whereas no changes in QM were noted in any diagnostic cohort except for NAFLD.

CONCLUSIONS

Although vaccination rates in CLD and diabetic cohorts are increasing, they remain low. Given the public health implications of acute hepatitis A and hepatitis B in patients with CLD, better implementation of the vaccination recommendations for these populations is warranted.

Review article: prevention and management of hepatitis B and C infection in patients with inflammatory bowel disease

BACKGROUND

Viral hepatitis is a very common infection.

AIM

To review the prevention and management of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in inflammatory bowel disease (IBD).

METHODS

Bibliographical searches were performed in MEDLINE up to September 2010.

RESULTS

The prevalence of both HBV and HCV infection in IBD patients is now similar to that of the general population. All IBD patients should be screened for HBV markers at diagnosis. Liver dysfunction in IBD patients treated with immunosuppressants is more frequent and severe in HBV than in HCV carriers and is associated with combined immunosuppression. Inpatients receiving anti-TNF drugs, HBV reactivation is common unless anti-viral prophylaxis is administered. HBsAg-positive patients should receive anti-viral prophylaxis before starting immunosuppressants. As interferon might worsen underlying IBD, nucleoside ⁄ nucleotide analogues are preferred for anti-viral prophylaxis in patients with HBV (tenofovir ⁄ entecavir are preferred to lamivudine). IBD patients should be vaccinated against HBV at diagnosis. The response rate to HBV vaccination is low, mainly in those receiving anti-TNF therapy. The serological response to HBV vaccine should be confirmed, and patients with an inadequate response should receive a second full series of vaccine. Peginterferon (ribavirin) for HCV infection is as effective and safe as in non-IBD patients.

CONCLUSIONS

The present manuscript poses a series of questions on the prevention and management of HBV/HCV infection in IBD, and attempts to answer them using scientific evidence in order to provide practical conclusions for the clinician.

Performance of the DiaSorin LIAISON(®) anti-HBs II for the detection of hepatitis B surface antibodies: comparison with the Abbott Architect anti-HBs assay

BACKGROUND

Detection of hepatitis B virus (HBV) surface antibodies (anti-HBs) is required in order to evaluate the response to hepatitis B vaccination and to optimize post-exposure monitoring. The widespread use of vaccines has highlighted the need for accurate and consistent quantification, yielding comparable quantitative results.

OBJECTIVES

This study assessed the adequacy of DiaSorin LIAISON(®) anti-HBs II assay in detecting anti-HBs antibodies and determined the correlation with Abbott Architect anti-HBs quantification.

STUDY DESIGN

Anti-HBs levels were measured in parallel using Abbott and DiaSorin kits on WHO international standard dilutions and 350 routine samples pre-screened with Abbott Architect anti-HBs. Three different serological panels were tested: vaccinated subjects (n=121); subjects with past HBV infection (n=109); and subjects with no HBV infection marker (n=69). Serial dilutions from nine high-titer anti-HBs samples were used to address linearity.

RESULTS

Anti-HBs concentration measured on WHO standard dilutions indicated a good calibration of DiaSorin values against international units, while results for Abbott were below those expected. A strong impact of the dilution matrix used was observed when performing dilutions on high-titer samples. Despite difference in absolute quantification, the overall clinical agreement between the two assays was 96.9%, with strong correlation (r=0.92) between concentrations and good linearity over the quantification range.

CONCLUSIONS

The DiaSorin LIAISON(®) anti-HBs II assay shows excellent standardization to the WHO standard and good linearity. The assay is suitable for current clinical laboratory practice.