Long-term effectiveness of plasma-derived hepatitis B vaccine 22-28 years after immunization in a hepatitis B virus endemic rural area: is an adult booster dose needed?

Analysis of epidemiological serosurvey of hepatitis B virus among people under 29 years of age in Jiangsu Province, China

Background: The purpose of this paper was to analyze the prevalence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core anti-body (anti-HBc)in1-29 years old living in the most populous eastern province of China,22 years after introduction of hepatitis B vaccine (HepB) vaccination of infants and provide provincial baseline data for developping a better prevention and control plan for hepatitis B virus (HBV)in Jiangsu Province, ChinaMethods: The incidence rates of HBV in Jiangsu province from 2004 to 2014 were obtained from the National Notifiable Disease Reporting System (NNDRS). A stratified cluster random sampling method was used to select 3,002 participants aged 1-29 years across 13 HBV monitoring points throughout the province, which had been classified as either urban or rural. HBV serological markers were measured by Abbott microparticle enzyme immunoassay (MEIA) kits (Abbott Laboratories, Chicago, Illinois).Results: The incidence of hepatitis B decreased by approximately 71.44% in Jiangsu province between 2004 and 2014. Serological assessments showed that the prevalence of the HBsAg, anti-HBc, and anti-HBsin the 1-29 age group were 1.20%, 5.33%,and 66.89%, respectively. There was a significantly lower prevalence of HepB who were vaccinated than in unvaccinated subjects (0.46% vs 14.93%, p < .0001). Among these the ages of 1-29, the coverage rate drops from 97.7% to 56.6% with age,andthe timely rate among people aged 1-14 years was 90.93%.Conclusions: Since the HepB was integrated into the immunization programme in Jiangsu province,the rate of hepatitis B reported and the prevalence of HBsAg decreased significantly, and the coverage of HepB and the vaccination rate within 24 hours after birth have played an important role in reducing HBV infection.

Seroconversion of hepatitis B surface antigen among those with previously successful immune response in Southern China

Recommendations promoted worldwide have suggested a period of protection lasting more than 20 years against hepatitis B (HB) following primary immunization. Starting in 1987, universal HB vaccinations were carried out in Long An County, Guangxi Province, one of the earliest counties in which plasma-derived HB vaccine was delivered to newborns across China. Data collection targeted toward understanding the long term (26–33 years since primary immunization) immune effects of the plasma-derived HB vaccine was conducted in 2015; a second data collection was carried out in 2019 to assess seroconversion in the same cohort. This study qualitatively compared positive vs negative results and quantitatively assessed HB biomarkers – HB surface antigen (HBsAg), antibody to HBsAg (anti-HBs), HB e-antigen (HBeAg), antibody to HBeAg (anti-HBe), and antibody to HB core antigen (anti-HBc) – in serum 26–33 years after the full initial course of HB vaccination, then analyzed anti-HBs seroconversion using the two-phase sampling method in the same cohort and calculated the anti-HBs seroconversion rate from 2015 to 2019. The protective sero-conversion rate (anti-HBs ≥10mIU/mL) was 37.6% (192/511); the HBsAg-positive rate was 5.3% (27/511); the anti-HBs mean geometric titer (GMT) was 11.1 mIU/mL. Among the 143 participants involved in both 2015 and 2019 data collections, the seroconversion rate was 3.5% (5/143); two individuals had protective anti-HBs levels in 2015. These findings indicate that anti-HBs status can be seroconverted to a protective concentration level 4 years earlier in a high HBV epidemic region. The role of genomic mutations and the disappearance of immune memory and seroconversion should be investigated.

Long-term persistence of anti-HBs after hepatitis B vaccination among isolated anti-HBc positive adults in China: 8-years results

The long-term persistence of hepatitis B surface antibody (anti-HBs) after hepatitis B vaccination among adults harboring isolated hepatitis B core antibody (anti-HBc) is not yet clarified. The present study aimed to assess the immunogenicity and persistence of antibodies in adults 8 years after vaccination. A total of 309 participants including 94 participants in the isolated anti-HBs group and 215 in the control group were recruited in this study. All subjects received three doses of hepatitis B vaccine (20 μg) at 0, 1, and 12 months, followed by testing for serological responses 1 month after the third vaccination. Subsequently, 154 participants were excluded because their anti-HBs data of 8 y after the first vaccination were missing. The prevalence of isolated anti-HBc was about 11.5%, the positive seroprotection rate was 72%, and the geometric mean titer (GMT) value of anti-HBs titer was 24.55 mIU/mL in the isolated anti-HBc group 8 y after three doses of vaccination. No significant difference was detected in the positive seroprotection rate (P = .434) and the GMT values of anti-HBs titers (P = .674) between the isolated anti-HBc and control groups after 8 y. In conclusion, isolated anti-HBc-positive subjects could achieve satisfactory long-term immune effects after hepatitis B vaccination. The GMT values of anti-HBs titers were lower than those of the control group at 1 month, but no significant difference was detected after 8 years.

Malaria vaccines: facing unknowns

Much of the gain in malaria control, in terms of regional achievements in restricting geographical spread and reducing malaria cases and deaths, can be attributed to large-scale deployment of antimalarial drugs, insecticide-treated bed nets, and early diagnostics. However, despite impressive progress, control efforts have stalled because of logistics, unsustainable delivery, or short-term effectiveness of existing interventions or a combination of these reasons. A highly efficacious malaria vaccine as an additional tool would go a long way, but success in the development of this important intervention remains elusive. Moreover, most of the vaccine candidate antigens that were investigated in early-stage clinical trials, selected partly because of their immunogenicity and abundance during natural malaria infection, were polymorphic or structurally complex or both. Likewise, we have a limited understanding of immune mechanisms that confer protection. We reflect on some considerable technological and scientific progress that has been achieved and the lessons learned.

Long-term persistence of anti-HBs after hepatitis B vaccination among adults: 8-year results

The long-term persistence of hepatitis B surface antibody (anti-HBs) after hepatitis B vaccination among adults was not known clearly. This study aimed to assess the immunogenicity and persistence of antibodies 8 years after hepatitis B immunization with different vaccination schedules among adults who tested negative for hepatitis B surface antigen (HBsAg), anti-HBs, and hepatitis B core antibody (anti-HBc). A total of 771 participants who received the full vaccination course (three doses) and also had a blood sample taken 1 month after the first vaccination were recruited. Of these, 529 were excluded due to the missing data of anti-HBs 8 years after the first vaccination. Vaccinations were carried out at 0-1-3, 0-1-6 and 0-1-12 month vaccination schedules, and 104, 45, and 93 participants were included, respectively. The positive seroprotection rate was 85.9% 1 month after the third vaccination, and 58.3% 8 years later (χ² = 54.52, P < .001), while the geometric mean titer (GMT) of anti-HBs was 158.49 mIU/mL [95% confidence interval (CI): 131.83-190.55)] and 15.14 mIU/mL (95% CI: 10.96-20.42) after 1 month and 8 years, respectively. Compared with the standard 0-1-6 month vaccination schedule, the positive seroprotection rate and the GMT of the 0-1-3 month vaccination schedule had no difference. The long-term immune effect of the 0-1-3 month vaccination schedule was better than that of the 0-1-12 month vaccination schedule. No correlation was found between the GMT of anti-HBs 1 month and 8 years later.

Long-term protection at 20-31 years after primary vaccination with plasma-derived hepatitis B vaccine in a Chinese rural community

Background: To assess the long-term protection conferred by plasma-derived hepatitis B vaccine at 20-31y after primary immunization during infancy in Chinese rural community.Method: Participants born between 1986 and 1996, who received a full course of primary vaccination with plasma-derived hepatitis B vaccine and had no experience with booster vaccination were enrolled. An epidemiological investigation was performed, and blood samples were collected to detect hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc). The positive rate of HBsAg, anti-HBs, and anti-HBc were calculated to evaluate the long-term protection of the plasma-derived hepatitis B vaccine.Results: A total of 949 participants were enrolled in the final analysis. Six subjects were detected to be HBsAg-positive, resulting in a HBsAg carrier rate of 0.63% (6/949). A total of 468 (52.41%) participants maintained a level of anti-HBs antibody ≥10 mIU/mL, with a GMC of 112.20 mIU/mL (95%CI: 97.72 ~ 128.82 mIU/mL). A significant downtrend was observed in the anti-HBs positive rate (P < .001). The average anti-HBc positive rate was 5.90% (56/949), increased with prolongation of immunization (P < .001).Conclusions: The plasma-derived hepatitis B vaccine maintained satisfactory protection at 20-31 y after primary immunization. These results indicate that a booster dose is not necessary. Further studies on the immune memory induced by the plasma-derived hepatitis B vaccine are needed.

Asymptomatic hepatitis B carriers who were vaccinated at birth

The long-term persistence of immunity following universal infant immunization against hepatitis B virus (HBV) and the need for a subsequent booster dose in adolescence remain under debate. With data derived from Long'an County, Guangxi, China, we reported previously that the prevalence of hepatitis B surface antigen (HBsAg) among adults born from 1987 to 1993 increases with age, although these individuals had received a first dose of the vaccine within 24 hours of birth. Here, we sought the source of transmission by comparison of genotypes among their family members using phylogenetic analysis of complete HBV S gene sequences. For comparison, we screened 2199 vaccinated individuals aged 5 to 17 in Cang Wu County and 1592 vaccinated individuals aged 3 to 7 in Ling Shan County in Guangxi for HBsAg carriers and investigate their family members. In total, 50 asymptomatic HBsAg carriers who were vaccinated at birth and 152 family members were analyzed. The results showed that 25% (95% CI: 6.0-44.0) of the HBsAg-positive children had not acquired their HBV infection from their mothers. This phenomenon showed a trend that increases with age. Antibody escape mutations were detected in 22.9% (95% CI: 11.0-34.8) of the isolates. In conclusion, a booster dose may be necessary for adolescence who were vaccinated at birth in highly endemic countries.

Prevalence of hepatitis B, C, and HIV among patients attending a teaching dental hospital. A 7-year retrospective study from the United Arab Emirates

Objectives

To determine the seroprevalence and case characteristics of hepatitis B, C and human immunodeficiency virus (HIV), and their transmissibility from patients to dental personnel following percutaneous and mucocutaneous injuries.

Methods

All incidents of sharp and splash injuries reported between January 2010 and January 2017 were retrospectively reviewed and analyzed. Descriptive statistics were calculated using the Statistical Package for the Social Science (SPSS). Prevalence was calculated as percentages, and chi-square test was used to assess categorical variables where a p-value of ≤0.05 was considered significant.

Results

Among the 436 reported incidents, 372 patients underwent serological screening. Fourteen patients (3.8%) had antibodies against hepatitis C virus, and 8 patients (2.2%) were positive for hepatitis B surface antigens. All positive cases were clinically asymptomatic. There were no positive cases for HIV. Three of the 14 hepatitis C positive patients were actively infectious upon polymerase chain reaction (PCR) analysis, but none of the injured dental personnel seroconverted upon a 6-month follow up. Approximately 88% of dental personnel were vaccinated against hepatitis B. Female personnel showed better vaccination rate by comparison to male personnel (p=0.005). Among the 5 different categories of professional status, cleaners showed a significantly low hepatitis B vaccination rate (p<0.000).

Conclusion

The prevalence of hepatitis B and C is higher than that previously reported from the United Arab Emirates, but transmissibility of viral hepatitis seems to be negligible.

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.