Perspectives of public health: present and foreseen impact of vaccination on the epidemiology of hepatitis B

Accelerating Decreases in the Incidences of Hepatocellular Carcinoma at a Younger Age in Shanghai Are Associated With Hepatitis B Virus Vaccination

Background

Routine vaccination of infants for protecting against hepatitis B virus (HBV) infection and its serious consequences, including hepatocellular cancer (HCC), has been carried out in Shanghai, China, since 1986. We therefore have examined the trend of HBV infection and HCC incidences before and after HBV vaccination over decades to assess the potential influences of the Shanghai HBV vaccination program.

Methods

Data on incidences of HBV infection and HCC were collected from the Shanghai Cancer Registry and the Shanghai HBV vaccination follow-up study. Joint-point regression and the Bayesian age-period-cohort statistical analysis methods were used.

Results

The incidences of HBV infection dramatically declined from 23.09 and 1.13 per 100,000 for males and females in 2000 to 3.24 (-85.97%) and 0.22 (-80.53%) per 100,000 in 2014, respectively. Sero-epidemiological data from the sampling surveys during 20 years of follow-up showed that less than 1% of people undergoing HBV vaccination have a positive serum HBsAg. Consistently, the annual adjusted standardization rates (ASR) of HCC steadily fell from 33.38 and 11.65 per 100,000 for males and females in 1973 to 17.34 (-49.2%) and 5.60 (-51.9%) per 100,000 in 2014, respectively. The annual percentage change in overall HCC incidences is about -2%. HCC incidences in males at younger age groups (age <50 years old), particularly in those with age <34 groups, showed an accelerating decrease over time, whereas HCC incidences significantly declined in the female population across all age groups except for those under 19 years of age. The results supported that the universal HBV vaccination in newborns is easy to implement with high coverages and is effective for preventing both HBV infection and HCC in populations.

Need to take special care of non-responders to hepatitis B vaccination among health-care workers, students and chronic patients

Both our research and that published by Sticchi et al. on immunological memory against hepatitis B virus (HBV) in health-care workers (HCWs) vaccinated as infants or adolescents confirm that in those testing negative after the primary course, one additional (fourth) booster dose is able to elicit an anti-HBs response in >85% subjects. The fifth and the sixth doses further contribute substantially to a high overall response rate. The rate of subjects showing an anamnestic response after the booster dose was almost six-fold higher in HCWs compared to chronic patients. Since universal vaccination in Italy resulted in a significant decrease in HBV infections, special attention and testing should be addressed to those affected by chronic diseases.

The persistence of anti-HBs antibody and anamnestic response 20 years after primary vaccination with recombinant hepatitis B vaccine at infancy

Hepatitis B (HB) vaccine induces protective levels of antibody response (anti-HBs≥10 mIU/mL) in 90-99% of vaccinees. The levels of anti-HBs antibody decline after vaccination. The aim of this study was to evaluate the persistence of anti-HBs antibodies and immunologic memory in healthy adults at 20 years after primary vaccination with recombinant HB vaccine. Blood samples were collected from 300 adults at 20 years after primary HB vaccination and their sera were tested for anti-HBs antibody by ELISA technique. A single booster dose of HB vaccine was administered to a total of 138 subjects, whose anti-HBs antibody titer was <10 mIU/mL. The sera of subjects were re-tested for the anti-HBs antibody levels at 4 weeks after booster vaccination. At 20 years after primary vaccination 37.0% of participants had protective levels of antibody with geometric mean titer (GMT) of 55.44±77.01 mIU/mL. After booster vaccination, 97.1% of vaccinees developed protective levels of antibody and the GMT rose from 2.35±6.49 mIU/mL to 176.28±161.78 mIU/mL. 125/138 (90.6%) of re-vaccinated subjects also showed an anamnestic response to booster vaccination. At 20 years after primary vaccination with HB vaccine, low proportion of the subjects had protective levels of antibody. However, the majority of the re-vaccinated subjects developed protective levels of anti-HBs and showed an anamnestic response after booster vaccination. Additional follow-up studies are necessary to determine the duration of immunological memory.

Seroprevalence of hepatitis B in two period birth cohorts of Bolivian children: effect of universal vaccination

BACKGROUND

Since 2000 universal routine immunization against the hepatitis B virus (HBV) was implemented in Bolivia. This study aimed to assess the seroprevalence of markers against HBV in two different birth cohorts (pre-universal vaccine cohort and post-universal vaccine cohort) from Cochabamba, Bolivia.

METHODS

We performed a school-based seroepidemiological survey (n = 424) of HBV in 2010 in the Cochabamba region. An ELISA test was used to measure antibodies to the hepatitis B surface antigen (anti-HBs IgG) and to the hepatitis B core antigen (anti-HBc IgG).

RESULTS

The prevalence of anti-HBs IgG in the pre-universal vaccine cohort was 5.8% (95% CI: 3.3-8.3%); it was higher in boys (9.1%), and those living in suburbs (9.7%). The anti-HBs IgG prevalence among post-universal vaccine cohort was 37.9% (95% CI: 28.5-48.1%), and was higher in children who spoke Quechua at home (51.0%), those living in suburbs (53.9%), and those born in 2005 (72.7%). Neither cohort showed differences relating to parental education. The prevalence of anti-HBc IgG was 1.1% among post-universal vaccine cohort and 1.2% among pre-universal vaccine cohort (p > 0.05).

CONCLUSIONS

This study identified a persistent low seroprevalence of hepatitis B infection in spite of a decade of universal immunization, and low long-term humoral immunity against HBV infection in vaccinated children in Cochabamba. 

Hepatitis B virus serum profiles in injection drug users and rates of immunization over time in Barcelona: 1987-2006

Injection drug users are at increased risk for hepatitis B. Surveillance of the unexposed to infection and of the vaccinated is necessary to understand the impact of interventions. We aimed to analyze HBV serum profiles and rates of HBV vaccination over 20 years.

METHODS

Cross-sectional study in IDUs admitted to detoxification between 1987 and 2006 in two hospitals in Barcelona, Spain. Clinical data and serum samples for HBV, HCV and HIV infections were collected. HBV serostatus was assessed with HBsAg, Anti-HBs and Anti-HBc.

RESULTS

A total of 1223 IDUs were eligible; 80.3% were men; median age at admission was 28 years. Prevalence of HCV infection and HIV infection was 84.2% and 44.3%, respectively. There was a significant (p<0.001) increase of the rates of HBV vaccine-induced immunity from 3.7% in period 1987-1991 to 19.9% in period 2002-2006 and, a significant (p<0.001) decline of those with HBsAg from 9.3% in 1987-1991 to <2% after 1997. The rates of absence of HBV markers and of natural immunity remained stable from 1992 onwards. In multivariate logistic regression model, HBV vaccination was significantly (p<0.001) less frequent in older individuals (OR=0.61 [95% CI: 0.50-0.74] for a 5-year increase in age) and in HIV infected patients (p=0.014) (OR=0.51 [95% CI: 0.30-0.87]).

CONCLUSIONS

In the 20-year period from 1987 to 2006, HBV vaccine-induced immunity in IDUs has shown an upward trend, although overall prevalence remained low. More effective interventions are needed to reduce high rates of HBV infection in this population.

Hepatitis B vaccination status among healthy adults in Germany

OBJECTIVES

The hepatitis B vaccination policy in Germany was intensified by the implementation of hepatitis B vaccination for adolescents in the vaccination calendar in 1995. To investigate the effect of this measure on the hepatitis B vaccination coverage of healthy adults, we analysed the hepatitis B vaccination status of blood donors. Furthermore, the reasons for vaccination and the relationship between vaccination status and age, sex, and current profession were studied.

METHOD

Using a standardised questionnaire, randomly incoming whole blood donors were asked for hepatitis B vaccination status, the reason for vaccination, gender, age and current profession. Multiple logistic regression analysis with vaccination status as dependent variable and age, gender and current profession as explanatory variables was performed.

RESULTS

Overall, 1519 (22.3%) of the 6812 interviewed whole blood donors were vaccinated against hepatitis B. Younger age was significantly associated with higher acceptance of hepatitis B vaccination with already 44.1% of whole blood donors aged 18-29 years being hepatitis B immunised. Beside health care workers, teaching professions and students showed the highest hepatitis B vaccination rate. Foreign travel was nearly an equivalently important reason for hepatitis B vaccination as occupational risks.

CONCLUSION

The high hepatitis B vaccination coverage among young and healthy adults indicates the success of the intensified hepatitis B vaccination policy since 1995. However, concentrating education measures on individuals with lower educational level and intensifying hepatitis B vaccination in the context of foreign travel could further increase the acceptance of hepatitis B vaccination.

Hepatitis B virus (HBV) DNA levels and the management of HBV-infected health care workers

Different guidelines exist for the management of hepatitis B virus (HBV)-infected health care workers (HCWs). Various HBV DNA levels are used as a cutoff level to determine whether an HBV-infected HCW is allowed to perform exposure-prone procedures (EPPs) or not. In this paper we discuss the factors that determine HBV DNA levels and the implications of different HBV DNA cutoff levels for EPP performing HCWs. If the level of HBV DNA in the serum of HCWs is used to determine acceptability for the conduct of EPPs, it is necessary to take into account the variability in time of HBV DNA levels in HBV carriers and the reliability and reproducibility of the molecular diagnostic test involved. The issue of standardization has to be addressed, before a universal, maximum level of viraemia for EPP performing HCWs can be introduced.