Hepatitis B immunity in adolescents and necessity for boost vaccination: 23 years after nationwide hepatitis B virus vaccination program in Taiwan

Hepatitis B surface antigen and antibody positivity among women of childbearing age after three decades of universal vaccination in South Korea

OBJECTIVES

We estimated the impact of universal hepatitis B immunization using 18-year data of women who are of childbearing age in South Korea.

METHODS

We used hepatitis B surface antigen (HBsAg) and antibody (anti-HBs) data of 145,993 women aged 20-49 years during 2001-2018 at the Gangnam CHA Medical Center. Annual prevalences of HBsAg and anti-HBs positivity were calculated and tested for linear trend. We conducted age-period-cohort (APC) analysis to obtain period and cohort effect.

RESULTS

Overall proportion of HBsAg positivity was 3.5% (n = 5050) and anti-HBs positivity was 75.3% (n = 109,907) during the study period. HBsAg positivity percentage decreased from 5.1% in 2001 to 2.5% in 2018 (P < 0.001) while anti-HBs positivity increased from 59.9% to 75.8% (P = 0.002). Average annual percent change of HBsAg positivity was -5.9% (95% confidence interval (CI): -6.9%, -4.8%). The period and cohort RR curve identified a consistent decrease in HBsAg positivity over time and across generations.

CONCLUSIONS

We observed a concurrent decrease in HBsAg and an increase in anti-HBs seropositivity among Korean women of childbearing age, implicating success in preventing vertical transmission.

Evaluation of the immune memory response to routine HBV vaccine in Egyptian patients with Type 1 diabetes

We aimed to evaluate the immune memory response to HBV vaccine in diabetic patients who had received the full HBV vaccination during infancy and to assess the need for booster doses. Blood samples were collected from children (93 diabetics and 105 controls) and university students (22 diabetics and 20 controls). Anti-HBs titer in serum and after in vitro stimulation of peripheral blood mononuclear cells with HBV vaccine was measured by ELISA. Diabetic groups had significantly lower anti-HBs levels after 10 years of the last HBV vaccine dose. The percentage of diabetic patients having protective anti-HBs titers was significantly lower than controls. In conclusion, diabetic patients had lower immune response to HBV vaccine over time, emphasizing the need for a booster dose.

Long-term impact of infant immunization on hepatitis B prevalence: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of the long-term impact of infant vaccination on the prevalence of hepatitis B virus (HBV) infection at the population level.

METHODS

We searched online databases for articles reporting comparisons between population cohorts aged ≥ 15 years who were exposed or unexposed to infant HBV immunization programmes. We categorized programmes as universal or targeted to infants whose mothers were positive for hepatitis B surface antigen (HBsAg). We included studies reporting prevalence of hepatitis B core antibody (HBcAb), HBsAg, or both. We evaluated the quality of the study methods and estimated the relative reduction in the prevalence of infection.

FINDINGS

Of 26 studies that met the inclusion criteria, most were from China (20 studies). The prevalence of HBV infection in unvaccinated and universally vaccinated cohorts ranged from 0.6% (116 of 20 305 people) to 16.3% (60/367) and from 0.3% (1/300) to 8.5% (73/857), respectively. Comparing cohorts with universal vaccination to those without vaccination, relative prevalences were 0.24 (95% confidence interval, CI: 0.16-0.35) for HBsAg and 0.23 (95% CI: 0.17-0.32) for HBcAb. For populations with targeted vaccination, relative prevalences were 0.32 (95% CI: 0.24-0.43) and 0.33 (95% CI: 0.23-0.45), respectively.

CONCLUSION

The residual burden of infection in cohorts offered vaccination suggests that longer-term evaluations of vaccination coverage, timeliness and other aspects of programme quality are needed. As HBV-vaccinated infant cohorts reach adulthood, ongoing analysis of prevalence in adolescents and young adults will ensure that elimination efforts are on track.

Three decades of neonatal vaccination has greatly reduced antenatal prevalence of hepatitis B virus infection among gravidae covered by the program

OBJECTIVES

To evaluate the impact of three decades of hepatitis B vaccination in infancy on antenatal prevalence of hepatitis B surface antigen (HBsAg) carriage in 93,134 Hong-Kong born gravidae managed in 1997-2015.

METHODS

Annual prevalence of HBsAg carriage on routine antenatal screening was examined with respect to maternal year of birth in three periods i.e. pre-1983 (before availability of vaccination), 1983-1988 (vaccination of infants born to HBsAg-carriers), and after 1988 (universal vaccination).

RESULTS

Overall HBsAg carriage was 8.3% (7737/93,134), decreasing from 10.5% in 1997 to 6.5% in 2015 (p < 0.001), and from 8.8%, 7.0% to 3.1%, respectively, for the three period-of-birth cohorts (p < 0.001). Annual prevalence decreased from 9.9% in 1997 to 7.5% in 2015 (p < 0.001) in the pre-1983 cohort, but showed neither difference nor trend in the other two cohorts. However, the annual prevalence showed significantly falling trends from the pre-1983 to the post-1988 cohorts for the years 2007-2008 and 2010-2015.

CONCLUSIONS

A progressive decline in overall annual prevalence of antenatal HBsAg carriage was found, with a consistently significant decline among the three cohorts for the years 2007-2008 and 2010-2015, providing evidence that universal hepatitis B vaccination in infancy has reduced significantly antenatal prevalence of HBsAg carriage in Hong Kong.

Changes and analysis of anti-HBs titres after primary immunization in 1- to 16-year-old Chinese children: A hospital-based study

Immunization with the hepatitis B vaccine is the most effective measure to prevent Hepatitis B Virus (HBV) infection. The aim of this study was to investigate the change in antibody levels induced by administration of the hepatitis B vaccine in children aged 1-16 year old in a large sample sized investigation. HBV markers were determined in 93 326 1- to 16-year-old hospitalized children who completed primary immunization as infants from south-west China, Chongqing. Analyses were performed on anti-HBs titre changes with increasing age, and the revaccination effect was evaluated in children aged 7-14. The percentage of protective antibody was between 45.29% and 63.33% in all age groups, but was higher in the 1-, 2- and 3-year-old groups (90.31%, 83.95% and 71.82%, respectively), and the rate of high-responder was 5.03%-10.56%, except in the 1-year-old group (23.33%). Additionally, 3.33%-25.79% of subjects had not seroconverted. There was no significant difference in antibody levels between girls and boys (P > .05). The Geometric Mean Titers in children with confirmed revaccination history were significantly higher than those with unknown or no revaccination history (P < .0001). In conclusion, the overall rate of protective anti-HBs was 67.10% with consecutive age groups from 1 to 16, it decreased from 90.31% to 45.29% for 1- to 8-year-old individuals, and interestingly, the rate increased from 45.46% to 63.33% for subjects aged 9-15. Anti-HBs titres were significantly improved after revaccination. Booster doses are recommended for those without seroconversion, especially children who live in school with other students or have family members with positive HBsAg.

The effects of booster vaccination of hepatitis B vaccine on children 5-15 years after primary immunization: A 5-year follow-up study

The aim of this study was to evaluate changes in hepatitis B surface antibody titers (anti-HBs) after booster vaccinations in children aged 5-15 y and to provide suitable immunization strategies. A total of 2208 children were initially enrolled in screening, and 559 children were finally included. The participants were divided into 2 groups according to their pre-booster anti-HBs levels: Group I, <10 mIU/ml and Group II, ≥10 mIU/ml. Group I was administered 3 doses of booster hepatitis B vaccine (0-1-6 months, 10 μg), and Group II was administered 1 dose of booster hepatitis B vaccine (10 μg). The antibody titer changes were examined at 4 time points: 1 month after dose 1 and dose 3, and 1 year and 5 years after dose 3. The protective seroconversion rates at those points were 95.65%, 99.67%, 97.59% and 91.05% (p < 0.001), respectively, in Group I, and 100.00%, 99.87%, 99.66% and 98.21% (χ² = 6.04, p = 0.11), respectively, in Group II. The GMT in subjects aged 5-9 y were higher than that in subjects aged 10-15 y in both Group I and Group II at 1 month after dose 1, but no difference was observed at the other three time points. This study demonstrates that booster vaccination has a good medium-term effect. A booster dose for subjects with protective antibodies is not necessary but effective, and 3 doses of hepatitis B vaccination are recommended for those who have lost immunological memory. Receiving booster immunization at the age of 10-15 years may be more appropriate for individuals living in HBV high epidemic areas.

A Single Center Analysis of the Positivity of Hepatitis B Antibody after Neonatal Vaccination Program in Korea

The antibody to hepatitis B surface antigen (anti-HBs) seropositivity rate after 3 doses of hepatitis B virus (HBV) vaccination during infancy period is known to be higher than 90%. However, a considerable number of vaccines do not form protective anti-HBs or chronologic decrease of anti-HBs. We retrospectively collected data of HBV serologic test results in 20,738 individuals from 2000 to 2015. After exclusion criteria were applied, 19,072 individuals were included. We analyzed the anti-HBs seropositivity rate, anti-HBs disappearance rate, anti-HBs positive seroconversion rate after receiving a booster vaccine, and the difference in anti-HBs positivity between the 2 groups; group A (born before 2005, while both recombinant vaccines and plasma-derived vaccines were used) and group B (born after 2005, when only recombinant vaccines were used by national regulation). The anti-HBs seropositivity rate was 55.8%, but there was a significant difference in the rate of seropositivity for anti-HBs between the group A and B (53.0% vs. 78.1%, P < 0.001). There was no significant age-adjusted difference in the mean seropositivity rate between the 2 groups (P = 0.058). In addition, the anti-HBs positivity rate was significantly lower in the group A as compared with the group B during infancy (83.1% vs. 92.1%, P < 0.001). A total of 1,106 anti-HBs-positive subjects underwent serologic tests more than twice. Of these, 217 subjects (19.6%) showed anti-HBs disappearance. After booster vaccinations, 87.4% (83/95) achieved seroconversion from seronegative to seropositive. Our results highlight the importance of lifelong protection against HBV and the possible necessity of booster vaccination after adolescent period.

Trends in the prevalence of hepatitis B infection among women giving birth in New South Wales

OBJECTIVES

To evaluate the effect of targeted and catch-up hepatitis B virus (HBV) vaccination programs in New South Wales on HBV prevalence among women giving birth for the first time.

DESIGN

Observational study linking data from the NSW Perinatal Data Collection for women giving birth during 2000-2012 with HBV notifications in the NSW Notifiable Conditions Information Management System.

MAIN OUTCOME MEASURES

HBV prevalence in Indigenous Australian, non-Indigenous Australian-born, and overseas-born women giving birth.

RESULTS

Of 482 944 women who gave birth to their first child, 3383 (0.70%) were linked to an HBV notification. HBV prevalence was 1.95% (95% CI, 1.88-2.02%) among overseas-born women, 0.79% (95% CI, 0.63-0.95%) among Indigenous Australian women, and 0.11% (95% CI, 0.09-0.12%) among non-Indigenous Australian-born women. In Indigenous Australian women, prevalence was significantly lower for those who had been eligible for inclusion in the targeted at-risk newborn or universal school-based vaccination programs (maternal year of birth, 1992-1999: 0.15%) than for those who were not (born ≤ 1981: 1.31%; for trend, P < 0.001). There was no statistically significant downward trend among non-Indigenous Australian-born or overseas-born women. HBV prevalence was higher among Indigenous women residing in regional and remote areas than those in major cities (adjusted odds ratio [aOR], 2.23; 95% CI, 1.40-3.57), but lower for non-Indigenous (aOR, 0.39; 95% CI, 0.28-0.55) and overseas-born women (aOR, 0.61; 95% CI, 0.49-0.77).

CONCLUSION

Among women giving birth, there was a significant reduction in HBV prevalence in Indigenous women associated with the introduction of the HBV vaccination program in NSW, although prevalence remains higher than among non-Indigenous Australian-born women, and it also varies by region of residence. Continuing evaluation is needed to ensure that the prevalence of HBV infections continues to fall in Australia.

Persistence of immunity 18-19 years after vaccination against hepatitis B in 2 cohorts of vaccinees primed as infants or as adolescents in Italy

This study was aimed at assessing the anti-HBs persistence and immune memory 18-19 y after vaccination against hepatitis B in healthy individuals primed as infants or adolescents. We enrolled 405 teenagers (Group A) vaccinated as infants, and 409 young adults (Group B) vaccinated as adolescents. All vaccinees were tested for anti-HBs and anti-HBc antibodies; those found anti-HBc positive were further tested for HBsAg and HBV DNA. Eight individuals belonging to Group B were positive for anti-HBc alone, and were excluded from analysis. Individuals with anti-HBs concentration ≥ 10 mIU/ml were considered protected while those with anti-HBs concentration <10 mIU/ml were offered a booster dose and re-tested 2 weeks later. Overall, 67.9% individuals showed anti-HBs concentrations ≥ 10 mIU/ml (48.9% in Group A vs 87.0% in Group B, p < 0.001). The antibody geometric mean concentration (GMC) was higher in Group B than in Group A (102.5 mIU/ml vs 6.9 mIU/ml; p < 0.001). When boosted, 94.2% of vaccinees with anti-HBs <10 mIU/ml belonging to Group A and 94.7% to Group B showed an anamnestic response. Post-booster GMCs were similar in both groups (477.9 mIU/ml for Group A vs 710.0 mIU/ml for Group B, p = n.s.). Strong immunological memory persists for at least 18-19 y after immunization of infants or adolescents with a primary course of vaccination. Thus, booster doses are not needed at this time, but additional follow up is required to assess the long-life longevity of protection.

Effects of hepatitis B vaccine boosters on anti-HBs-negative children after primary immunization

This study was aimed at evaluating the changes of hepatitis B surface antibody (anti-HBs) titer after booster vaccinations in 5-15-year-old children with negative antibodies (<10 mIU/mL). 225 subjects (mean age, 9.28 ± 2.95 years) included in the study consisted of 123 males and 102 females, with a complete hepatitis B vaccination during infancy. The participants were divided into 3 groups according to their pre-booster anti-HBs level: Group I, <0.1 mIU/mL; Group II, 0.1 to <1.0 mIU/mL; Group III, 1.0 to <10.0 mIU/mL. All the participants were administered 3 doses of booster hepatitis B vaccination (0-1-6 month, 20 µg), and changes in the levels of antibodies were examined at 4 time-points (one month after the first and the third dose, one year and 5 years after the third dose). The seroprotective rate (defined as anti-HBs ≥10.0 mIU/mL) among 225 subjects at the 4 time-points were 93.8%, 100%, 83.6% and 73.4%, respectively (χ² = 90.29, p < 0.05). The seroprotective rate (≥10 mIU/mL) and anti-HBs geometric mean titer (GMT) in Group III were always higher than those in the other 2 groups (all p < 0.05). The immune effect of a 3 -dose booster revaccination is good, and the booster-induced immune response was correlated with the pre-booster titer level, and ≥1.0 mIU/mL ensuring a robust positive response, whereas titers below this value may indicate the need for a course of booster vaccination.

Prevalence of hepatitis B surface antigen (HBsAg) in a blood donor population born prior to and after implementation of universal HBV vaccination in Shenzhen, China

Background

Neonatal hepatitis B vaccination program at birth has been implemented nationwide since 1992 in China. However, current HBV prevalence status in blood donors has not been entirely examined, which may impact HBV safety in blood donations as the vaccinees over 18 years old progressively become the majority population of blood donors.

Methods

In this study, 569,145 blood donors were screened for HBsAg by rapid tests and enzyme immunoassays, among them 475,538 blood samples with negative HBsAg were further screened for HBV DNA by nucleic acid testing between 2005 and 2014 at Shenzhen blood center.

Results

An overall 2.3 % HBsAg prevalence was found in the blood donor population during the past 10 years (2.86 % in 2005, 1.76 % in 2010, and 2.79 % in 2014, respectively). HBsAg seroconversion occurred in 0.37 % of repeat-donors. When stratified by age, the prevalence of HBsAg was found significantly higher in younger donors age 18–25 years (2.73 %) than in those 26–35 years (2.13 %), 36–45 years (2.03 %) and 46–58 years (1.71 %) (P < 0.001), unexpectedly suggesting that younger donors remained at risk of chronic HBV infection. Assuming that donors aged 18–22 born before or after 1992 were non-vaccinated and vaccinated, respectively, HBsAg prevalence was higher in first-time donors born ≥1992 (3.9 %) than prior to 1992 (3.5 %, P = 0.005). The incidence of HBV infection in the 5-year period examined was significantly lower in repeat-donors born ≥1992 (0.27 %) than prior to 1992 (0.6 %, P = 0.008). The yield of HBV DNA+/HBsAg- donors was 1:3,302, including 1:4,486 occult infections and 1:43,231 window period infections.

Conclusion

Young blood donors born after implementation of universal HBV vaccination in China presented higher prevalence of HBsAg but lower incidence of HBsAg seroconversion than older, presumed unvaccinated, donors. HBV vaccine boosting for adolescents at 15–17 years old prior to reaching blood donor age might help improve blood safety.

The one year effects of three doses of hepatitis B vaccine as a booster in anti-HBs-negative children 11-15 years after primary immunization; China, 2009-2011

The aim of this study was to evaluate hepatitis B surface antibody (anti-HBs) levels one year after hepatitis B booster vaccination in anti-HBs-negative (<10 mIU/mL) children 11-15 y after primary vaccination. Anti-HBs titers were examined in 235 children who were negative for hepatitis B surface antigen (HBsAg), anti-HBs, and hepatitis B core antibody (anti-HBc). The children were then divided into 3 groups based on their anti-HBs levels pre-booster: Group I, <0 .1 mIU/mL; Group II, 0.1 to <1 .0 mIU/mL; and Group III, 1.0 to <10 .0 mIU/mL. They were vaccinated with 3 doses of hepatitis B vaccine (0-1-6 month, 20 ug), and anti-HBs levels were measured. One month after the first dose, the anti-HBs positive rates (≥ 10 mIU/mL) in Groups I-III were 56.14%, 83.61% and 100%. One month after the third dose, the anti-HBs-positive rates in Groups I-III were 96.49%, 98.36% and 100%. One year after the third dose, the anti-HBs-positive rates in Groups I-III were 73.68%, 75.41% and 98.29%, respectively. Protective levels declined more rapidly for those with lower titers. Children with pre-booster anti-HBs titers of 1-9.9 mIU/mL might not need any booster dose, and the children with pre-booster titers of 0.1-0.9 and <0 .1 mIU/mL might need more than one dose booster vaccination.

The Serum Anti-HBs Level Among Children Who Received Routine Hepatitis B Vaccination During Infancy in Mianyang City, China: A Cross-Sectional Study

Hepatitis B virus (HBV) prevalence has declined remarkably in children due to nationwide universal vaccination program for HBV in China. However, the persistence of immune response against HBV infection and the optimal time point when a booster vaccination should be performed remain to be elucidated. To assess the persistence and level of antibody against hepatitis B surface antigen (anti-HBs) in a representative population of age 15 and younger who received routine hepatitis B vaccination in Mianyang City, China. A cross-sectional study was conducted in 2011. One thousand five hundred twenty-six children of age 15 and younger who received three doses of 5 μg hepatitis B vaccine series during infancy but did not receive a booster vaccination later were enrolled. Of the 1,526 children, the mean age was 8.2 ± 4.1 and 739 children were male. The median anti-HBs level was 23.0 mIU/mL, and the total percentage of anti-HBs levels ≥10 mIU/mL was 60.9%. With an increase of age, median anti-HBs level, percentage of anti-HBs levels ≥10 mIU/mL, and percentage of anti-HBs levels ≥100 mIU/mL declined remarkably in the early period and reached the lowest level at the age of 3 and then remained relatively stable. The median anti-HBs level, the percentage of anti-HBs levels ≥10 mIU/mL, and the percentage of anti-HBs levels ≥100 mIU/mL in 1- and 2-year-old children were much higher than that in children aged 3-15 (p < 0.05, respectively). Immunity against HBV infection gradually decreased in early ages of children of 15 and younger who received three doses of 5 μg hepatitis B vaccine series during infancy in China. Three dosages of 10 μg hepatitis B vaccine for infants and repeated vaccination or additional booster vaccination for some children at or before age 3 should be provided to get much more powerful immunity to HBV.

Persistence of Anti-HBs Among Palestinian Medical Students After 18 - 22 Years of Vaccination: A Cross-Sectional Study

BACKGROUND

Hepatitis B infection is a global public health problem affecting various sectors in the society. Vaccination is the first line measure to prevent the disease.

OBJECTIVES

To assess the persistence of anti-HBs marker among medical students after 18 - 22 of vaccination as an indicator for Hepatitis B virus vaccine efficacy.

PATIENTS AND METHODS

In this study, 249 Palestinian medical students vaccinated at birth, 1, and 6 months of age using Engerix™-B starting from 1992 were studied. About 58% (144/249) of the students were Palestinians holding Israeli citizenship, while 42% (105/249) were Palestinians from the West Bank. Students were tested serologically for anti-HBs, as a marker for vaccine-induced immunity.

RESULTS

Over 75% (188/248) of students had levels of anti-HBs greater than 10 mIU/mL indicating immunity and protection. Five cases had positive results for anti-HBc indicating exposure to HBV infection; however, none of these cases showed any sign of HBV-DNA indicating effective clearance of the virus by the vaccine. Around 57% of the study group had anti-HBs level of 100 - 1000 mIU/mL. No significant association was found between anti-HBs level and age, sex, locality and level of anti-HBc (P > 0.05). The students were aware of different aspects of hepatitis B infection regarding the virus, symptoms, prevention and mode of transmission.

CONCLUSIONS

The Palestinian and Israeli official policies to give a booster dose for risk groups like medical students at anti-HBs level below 10 mIU/mL should continue to ensure absolute protection. The currently-used vaccine and its time program cleared virus from students believed to have been exposed to the virus during their lifetime.

Response to booster doses of hepatitis B vaccine among young adults who had received neonatal vaccination

Background

Newborns who have received hepatitis B immunization in 1980s are now young adults joining healthcare disciplines. The need for booster, pre- and post-booster checks becomes a practical question.

Aims

The aim of this study is to refine the HBV vaccination policy for newly admitted students in the future.

Methods

A prospective study on medical and nursing school entrants to evaluate hepatitis B serostatus and the response to booster doses among young adults.

Findings

Among 212 students, 17–23-year-old, born after adoption of neonatal immunization, 2 (0.9%) were HBsAg positive, 40 (18.9%) were anti-HBs positive. At 1 month after a single-dose booster for anti-HBs-negative students, 14.5% had anti-HBs <10 mIU/mL, 29.0% and 56.5% were 10–100 and >100 mIU/mL, respectively. The anti-HBs levels were significantly higher for females than males (mean [SD]: 431 [418] vs. 246 [339] mIU/mL, P = 0.047). At 2–4 month after the third booster dose, 97.1% had anti-HBs >100 mIU/mL and 2.9% had 10–100 mIU/mL.

Conclusions

Pre-booster check is still worthwhile to identify carriers among newly recruited healthcare workers born after adoption of neonatal immunization. A 3-dose booster, rather than a single dose, is required for the majority to achieve an anti-HBs level >100 mIU/mL, as memory immunity has declined in a substantial proportion of individuals. Cost-effectiveness of post-booster check for anti-HBs is low and should be further evaluated based on contextual specific utilization of results.

Seroprevalence of hepatitis B and immune response to hepatitis B vaccination in Chinese college students mainly from the rural areas of western China and born before HBV vaccination integrated into expanded program of immunization

The prevalence of hepatitis B surface antigen (HBsAg) in a population aged 15 y or older was high in China, but an immunization strategy for this population was unavailable. We investigated the seroprevalence of hepatitis B and immune response to HBV vaccine in Chinese college students (n=2040 participants), 11.1%, 80.8%, and 8.1% had confirmed, unknown and no HBV vaccination history, respectively. The seropositive rates for HBsAg, anti-HBs sole and anti-HBs plus anti-HBc were 12.6%, 25.7%, and 30.1%, respectively. The HBsAg seropositive rate was significantly lower in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (5.3%, 13.6%, and 12.6%, respectively, P=0.0019). The anti-HBs alone seropositive rate was significantly higher in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (37.6%, 25.3%, and 13.8%, respectively, P<0.0001). Participants negative for HBsAg, anti-HBs, and anti-HBc at baseline (n=600) were given three doses of recombinant HBV vaccine (GlaxoSmithKline) at month 0, 1, and 6. Robust immune response was elicited after two and three doses (seroprotective rate: 91.9% and 99.0%, respectively, and geometric mean concentration [GMC]: 95.8 and 742.6 IU/L, respectively). Fourteen months after the third dose, the anti-HBs seroprotective rate of the group remained more than 97%. The seroprotective rates and GMCs did not differ significantly by vaccination history. This study suggested that three doses of 20 μg HBV vaccine were needed for college students negative for HBsAg, anti-HBs, and anti-HBc to ensure high seroprotective rates and concentrations.

Efficacy of hepatitis B vaccine boosters among neonatally vaccinated university freshmen in Taiwan

BACKGROUND & AIMS

Long-term protection against hepatitis B virus (HBV) after vaccination remains widely debated. We evaluated the efficacy of a modified 3-dose booster protocol in neonatally vaccinated university students in Taiwan.

METHODS

Changes in the levels of antibodies to the hepatitis B surface antigen (anti-HBs) were examined in 250 university students over a 3-year period. Group A (n=39) lacked seroprotective levels of anti-HBs, and declined to receive a booster dose of the HBV vaccine. Group B (n=128) lacked seroprotective levels of anti-HBs, and received booster doses of the HBV vaccine according to a modified 3-dose booster protocol. Group C (n=83) possessed seroprotective levels of anti-HBs, and did not receive a booster dose.

RESULTS

The levels of seroprotective anti-HBs increased in 12.8% of Group A and 14.5% of Group C, suggesting that our entire cohort had experienced booster effects from natural HBV exposure. However, no new HBV infections were observed, and 53.9% of Group B maintained protective levels of anti-HBs during the follow-up period.

CONCLUSIONS

The use of the modified 3-dose booster protocol induced significant long-term increases in the titer of anti-HBs in over 50% of the neonatally vaccinated participants with previously non-protective titers. However, in the absence of a vaccine booster, some neonatally vaccinated people with low anti-HBs titers may nonetheless produce anamnestic responses to HBV upon exposure, suggesting that protection from neonatal vaccination may persist, despite low titers of anti-HBs.

Hepatitis B vaccination at three months of age: a successful strategy?

Vaccination of infants, children and adolescents against the hepatitis B virus (HBV) is mandatory in Italy. It is crucial to assess whether vaccinated subjects have protective antibody level during adulthood when the risk of HBV infection increases due to lifestyle or occupational exposure. Two groups of students attending to University of Padova Medical School were enrolled between 2004 and 2011 and HBV antibodies and antigens were measured. The first group (Group A) comprised students vaccinated at three months of age and the second group (Group B) comprised students vaccinated after the first year of life. The follow-up was 18.0 (Group A) and 17.9 (Group B) years. The students vaccinated at three months of age had a higher rate of non-protective antibodies (47.2%) comparing to those vaccinated after the first year of life (17.0%, P<0.0001) with a significantly lower antibody level (P<0.001). The rate of non-protective antibodies was inversely related to vaccination age. The results clearly show that children vaccinated after the first year of life are better protected against HBV. On the other hand, both groups show a good immunological memory as evidenced by the achievement of protective antibody level after the booster dose in 97.8% of subjects.

The end of the Australia antigen? An ecological study of the impact of universal newborn hepatitis B vaccination two decades on

BACKGROUND

A universal newborn hepatitis B (HBV) vaccination program was introduced in the Northern Territory of Australia in 1990, followed by a school-based catch-up program. We evaluated the prevalence of hepatitis B infection in birthing women up to 20 years after vaccination and compared this to women born before the programs commenced.

METHODS

A cohort of birthing mothers was defined from Northern Territory public hospital birth records between 2005 and 2010 and linked to laboratory confirmed notifications of chronic HBV, based principally on a record of hepatitis B surface antigen detection. Prevalence of HBV was compared between women born before or after implementation of the newborn and catch-up vaccination programs.

FINDINGS

Among 10797 birthing mothers, 138 (1.3%) linked to a chronic HBV record. HBV prevalence was substantially higher in Aboriginal women compared to non-Indigenous women (2.4% versus 0.04%; p<0.001). Among 5678 Aboriginal women, those eligible for catch-up and newborn HBV vaccination programs had a significantly lower HBV prevalence than older women born prior to the programs: HBV prevalence respectively 2.2% versus 3.5%, (OR 0.61, 95%CI 0.43-0.88) and 0.8% versus 3.5% (OR 0.21, 95%CI 0.11-0.43). This represents a risk reduction of respectively 40% and 80% compared to unvaccinated women.

INTERPRETATION

The progressively greater reduction in the prevalence of chronic HBV in adult Aboriginal women co-inciding with eligibility for catch-up and newborn vaccination programs is consistent with a significant impact from both programs. The use of data derived from antenatal screening to track ongoing vaccine impact is applicable to a range of settings globally.

Effects of cytokine and cytokine receptor gene variation on high anti-HB titers: following up on Taiwan's neonatal hepatitis B immunization program

BACKGROUND

A significant percentage of Taiwanese neonatal HB immunization recipients have subsequently exhibited low anti-HB titers at non-protective or undetectable levels. Several mechanisms have been proposed to explain this phenomenon, including low vaccination responsiveness, deficient lymphocyte function, inappropriate antigen processing and presentation, and abnormal cytokine secretion.

METHODS

To determine genetic influences resulting in high anti-HB titers, we divided a study cohort of 183 individuals into an anti-HBs≥1000 mIU/mL group and a 10-1000 mIU/mL anti-HBs titer group. Chi-square tests were used to compare genotype and allelic frequencies between the two groups.

RESULTS

Data from univariate and multivariate regression analyses of cytokine and cytokine receptor gene variants indicate (a) increased potential of high anti-HB titers in the presence of the TT genotype of the IL-4 rs2243250 SNP (OR=3.19; p=0.012) and the AA genotype of the IL-4R rs1805010 SNP (OR=2.25; p=0.048), and (b) individuals carrying the TT genotype of the IL-4 rs2243250 SNP had anti-HB titers at levels that were almost twice as high as those in individuals carrying the CC genotype (478.8 mIU/mL and 290.3 mIU/mL, respectively; p=0.033).

CONCLUSION

Genetic determinants, especially IL-4 and IL-4R, may contribute to high anti-HB titers in immune responses to HB vaccinations.

Management of hepatitis B in developing countries

Hepatitis B is one of the leading causes of chronic hepatitis in developing countries, with 5% to 15% of the population carrying virus. The high prevalence is due to failure to adopt appropriate measure to confine the spread of infection. Most hepatitis B patients present with advanced diseases. Although perinatal transmission is believed to be an important mode, most infections in the developing world occur in childhood and early adulthood. Factors in developing countries associated with the progression of chronic hepatitis B (CHB) include co-infections with human immunodeficiency virus, delta hepatitis virus, hepatitis C virus, alcohol intake and aflatoxin. Treatment protocols extrapolated from developed countries may need modifications according to the resources available. There is some controversy as to when to start treatment, with what medication and for how long? There is now enough evidence to support that hepatitis B patients should be considered for treatment if they show persistently elevated abnormal aminotransferase levels in the last 6 mo, checked on at least three separate occasions, and a serum hepatitis B virus DNA level of > 2000 IU/mL. Therapeutic agents that were approved by Pure Food and Drug Administration are now available in many developing countries. These include standard interferon (INF)-α, pegylated INF-α, lamivudine, adefovir, entecavir and telbivudine. Drug resistance has emerged as a major challenge in the management of patients with CHB. The role of the universal vaccination program for effective control of hepatitis B cannot be emphasized enough.

Multiple vaccinations: friend or foe

Few immunotherapists would accept the concept of a single vaccination inducing a therapeutic anticancer immune response in a patient with advanced cancer. But what is the evidence to support the "more-is-better" approach of multiple vaccinations? Because we are unaware of trials comparing the effect of a single vaccine versus multiple vaccinations on patient outcome, we considered that an anticancer immune response might provide a surrogate measure of the effectiveness of vaccination strategies. Because few large trials include immunologic monitoring, the majority of information is gleaned from smaller trials in which an evaluation of immune responses to vaccine or tumor, before and at 1 or more times following the first vaccine, was performed. In some studies, there is convincing evidence that repeated administration of a specific vaccine can augment the immune response to antigens contained in the vaccine. In other settings, multiple vaccinations can significantly reduce the immune response to 1 or more targets. Results from 3 large adjuvant vaccine studies support the potential detrimental effect of multiple vaccinations as clinical outcomes in the control arms were significantly better than that for treatment groups. Recent research has provided insights into mechanisms that are likely responsible for the reduced responses in the studies noted above, but supporting evidence from clinical specimens is generally lacking. Interpretation of these results is further complicated by the possibility that the dominant immune response may evolve to recognize epitopes not present in the vaccine. Nonetheless, the Food and Drug Administration approval of the first therapeutic cancer vaccine and recent developments from preclinical models and clinical trials provide a substantial basis for optimism and a critical evaluation of cancer vaccine strategies.

Anti-HBs levels among children and adolescents with complete immunization schedule against hepatitis B virus. A cross-sectional study in Blumenau, State of Santa Catarina, Brazil, 2007-2008

INTRODUCTION: Vaccination is the main tool for preventing hepatitis B virus (HBV) infection; however, following the completion of the vaccination series, the concentrations of anti-HBs can decline over the years and reach levels less than 10mIU/mL. The persistence of protection in these individuals is still unknown. The present study aimed to determine the anti-HBs antibody levels among children and adolescents who had received a complete vaccination course for hepatitis B. METHODS: Antibodies against HBV surface antigen (anti-HBs) were tested in 371 individuals aged 10 to 15 years-old. RESULTS: Volunteers who showed undetectable quantities of anti-HBs accounted for 10.2% of the population studied and 39.9% presented antibody titers of less than 10mIU/mL. Anti-HBs ≥ 10mIU/mL were verified in 49.9%. CONCLUSIONS: These results corroborate other studies indicating levels of anti-HBs below 10mIU/mL in vaccinated individuals. Additional studies are required to assess whether this indicates susceptibility to HBV infection and the need and age for booster doses.

Efficacy of the nationwide hepatitis B infant vaccination program in Taiwan

BACKGROUND

Taiwan launched a nationwide infant vaccination program for hepatitis B (HB) in 1984.

OBJECTIVES

This study evaluated the seroprevalence of hepatitis B virus (HBV) and the incidence of high alanine aminotransferase (ALT) level among young adults prior to, during, and since the introduction of the nationwide HBV vaccination program.

STUDY DESIGN

Researchers recruited 101,584 freshmen (male:female=1.114:1; mean age, 18.5±0.5 years) from 21 universities between 1995 and 2009 (birth cohorts 1977-1991) in Taiwan, testing for serum hepatitis B surface antigens (HBsAg), hepatitis e antigens (HBeAg), antibodies against HBsAg (anti-HBs), and liver function tests, including ALT and aspartate aminotransferase (AST).

RESULTS

The results showed that the prevalence of HBsAg decreased significantly from 14.3% in 1995 to 1.1% in 2009 and the seroprevalence of HBeAg decreased significantly from 5.9% in 1995 to 0.3% in 2009. Seroconversion to anti-HBs maintained a steady rate above 50% between 1995 and 2007, but declined considerably to 36.6% and 36.4% in 2008 and 2009, respectively. Subject with HBeAg seropositivity was in 43.94% of HBV carriers. Double seronegativity for HBsAg and anti-HBs was observed in 2007 (47.8%), 2008 (62.3%), and 2009 (62.5%). High ALT level was observed in 5.74% of the subjects, particular among HBV-carriers (16.5% of HBV carrier vs. 5.0% of non-HBV carrier; ORs, 3.733; 95% CIs, 3.463-4.023, p<0.0001). Subjects with high ALT level were significantly positively associated with HBeAg (10.5% of HBeAg seropositive vs. 1.9% of HBeAg seronegative; ORs, 6.195; 95%CI, 5.629-6.818; p<0.0001). Male subjects were more easily infected by HBV than female subjects were (HBsAg, ORs, 1.355, 95% CI, 1.283-1.431; HBeAg, ORs, 1.324, 95% CI, 1.218-1.439, p<0.0001), and significantly more male subjects had high ALT levels than female subjects did (ORs, 4.087; 95% CI, 3.819-4.375, p<0.0001).

CONCLUSIONS

The mass vaccination program successfully reduced the HBV carrier rate and prevalence of chronic hepatitis B in Taiwan. However, the low percentage of anti-HBV in 2008 and 2009 remains unresolved.

Distribution Characteristics of Hepatitis B Serological Markers in Hospitalized Children and Adolescents in Zhejiang, China between 2006 and 2010

Background/Aims

To investigate serological patterns of hepatitis B based on electrochemiluminescent immunoassays and the distribution characteristics of these patterns in hospitalized children and adolescents in Zhejiang, China between 2006 and 2010.

Methods

Five serological markers, including hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), antibody to hepatitis B surface antigen (anti-HBs), antibody to hepatitis B e antigen (anti-HBe), and antibody to hepatitis B c antigen (anti-HBc), were chosen as a routine panel to monitor hepatitis B virus (HBV) infection and vaccination efficacy. A total of 33,187 children (21,187 boys and 12,000 girls) were selected using the following exclusion criteria: a previous diagnosis of hepatitis, age >16 years or an address outside of Zhejiang.

Results

The average HBV vaccination coverage rates among 20,766 boys and 11,782 girls were 98.62% and 98.68%, respectively. Seventeen serological patterns of hepatitis B were found, and the dominant pattern was 'anti-HBs (+) alone' (62.03%) followed by 'negative pattern' (23.46%). The rates of the other 15 patterns ranged from 8.14% to 0.003%. Of 236 HBsAg-positive patients, the overall rate of seropositivity was 0.71%. The anti-HBs levels were grouped into 3 ranges (10-100 mIU/mL, 100-1,000 mIU/mL, and >1,000 mIU/mL) for all anti-HBs-positive children (36.08%, 43.43%, and 20.49%, respectively).

Conclusions

A low HBsAg carrier rate and a relatively high anti-HBs positive rate are present in hospitalized children and adolescents in Zhejiang. The distribution of serological patterns is associated with age but is mostly independent of gender.

Prevalence of protective level of hepatitis B antibody 3 years after revaccination in HIV-infected children on antiretroviral therapy

After responding to highly active antiretroviral therapy (HAART), HIV-infected children had a good response to hepatitis B immunization. However, there are limited data on the durability of antibody to hepatitis B surface antigen (anti-HBs) in these children. The primary objective of this study is to determine the prevalence of protective anti-HBs level 3 years after a 3-dose HBV revaccination among HIV-infected children with immune recovery (CD4 cell ≥ 15%) while on HAART. The secondary objective is to assess immunologic memory among children who had waning of anti-HBs. An anti-HBs level of ≥ 10 mIU/mL was defined as a protective antibody level. Sixty-nine HIV-infected children who had history of a 3-dose HBV revaccination while receiving HAART were enrolled. The mean (SD) of CD4 cell and duration of HAART at time of revaccination was 27.2% (6.7) and 5.9 years (0.4), respectively. The proportion of children with protective anti-HBs level 3 years after the revaccination was 71.0% [95% CI, 58.8-81.3]. The geometric mean titer was 114(SD 5)IU/mL. By multivariate logistic analysis, the predictors for protective anti-HBs level 3 years after revaccination were CD4 cell count ≥ 500 cells/mm³ at the time of vaccination (p = 0.04) and anti-HBs level ≥ 100 IU/mL at 1 month after completion of the 3-dose vaccination (p < 0.001). Anamnestic response after one booster dose was demonstrated among 14 of 17 children who had waning protective anti-HBs level (82.4% [95% CI, 62.2-102.6]). Our findings support the recommendation of giving a 3-dose HBV vaccination to HIV-infected children with immune recovery while receiving HAART.

Immunity to hepatitis B vaccine among health care workers

The aim of this study was to determine the level of anti-HBsAg (hepatitis B surface antigen) in vaccinated high risk group. We measured anti-HBsAg concentration in blood sera of adult students aged from 19 to 37 years old. Five milliliters (5ml) of blood sample was taken from 210 cases four months after the second dose and 126 out of 210 cases three months after the third dose of hepatitis B vaccination. All blood samples were analyzed for anti-HBsAg by ELISA method. 125 out of 210 samples (59.5%) showed anti-HBsAg concentrations higher than 20mIu/ml and considered immune after the second dose of hepatitis B vaccination. Also, 99.2% of samples had anti-HBsAg higher than 20mIu/ml three months after the third dose of the vaccination. Non-immune cases in males were more than females (41.2% vs.40.1%). In conclusions, our results reinforce the importance of hepatitis B vaccine in adolescents and suggest that three dose of hepatitis B vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults.

Serological surveillance and IL-10 genetic variants on anti-HBs titers: hepatitis B vaccination 20 years after neonatal immunization in Taiwan

BACKGROUND

The national hepatitis B (HB) vaccination program in Taiwan that began in 1984 has resulted in a significant reduction in the carrier rate among children. However, a significant proportion of Taiwanese neonatal HB immunization recipients have exhibited low anti-HBs titers that fall to non-protective or undetectable levels.

METHODS

We recruited 1677 entering freshman and graduate student participants at a Taiwanese university health center, grouped them into three age groups representing three stages of Taiwan's HB vaccination program, then conducted hepatitis B surface antigen (HBsAg) and antibodies to HBsAg (anti-HBs) serological surveillances for each individual. Univariate and multivariate regression analyses of clinical characteristics and Interleukin-10 (IL-10) genetic variations were also conducted.

RESULTS

A trend toward a decreasing HBsAg carrier rate was observed over the starting dates of the vaccination program (11.7%, 1.6% and 1.7% for age groups 1, 2 and 3, respectively), but we also observed an increasing rate of non-protective anti-HBs titers (15%, 26% and 50.3% for cohorts 1-3, respectively). The percentage of students with non-protective anti-HBs titers increased from 23.1% for students born in 1984, to 25.2% for those born in 1985, to 39.4% for birth-year 1986 students, to 45.7% for birth-year 1987 students, and to 56.5% for birth-year 1988 students. The risk for low anti-HBs titers increased concurrently with increases in systolic blood pressure (BP), the IL-10 ATA/ACC haplotype, and the IL-10 ATA present haplotype. Risk for low anti-HBs titers decreased with concurrent decreases in glucose ante cibum (AC, before meals) and the IL-10 ACC/ACC haplotype.

CONCLUSIONS

These results suggest that the genetic determinants may also contribute to variations in anti-HBs titers in immune responses to HB vaccination.

HEPATITIS B AND PREGNANCY, THE SCIENTIFIC BASIS FOR PERINATAL PREVENTION

Hepatitis B and its complications are one of the major global health problems. Around 2 billion individuals are infected by hepatitis B virus (HBV) worldwide, more than 350 million are chronically infected, and approximately 15 to 40 percents of them will develop serious complications such as liver cirrhosis, hepatic failure, or hepatocellular carcinoma (HCC). The worldwide prevalence of chronic HBV infection ranges from 0.1 to 20 percent and varies widely in different geographic areas. According to the prevalence rate, WHO has classified countries into 3 levels: high areas (>8%) such as Africa, Asia, Western Pacific and Middle East; intermediate areas (2–8%) such as South America and Eastern Europe, and low areas (<2%) such as Western Europe, North America, and Australia.