Seroconversion after hepatitis B vaccination in healthy young adults, and the effect of a booster dose

The First Assessments of Pediatric HBV Immunization Coverage in Mauritania and Persistence of Antibody Titers Post Infant Immunizations

Background: The Hepatitis B virus (HBV) vaccine is used worldwide as an efficient tool to prevent the occurrence of chronic HBV infection and the subsequent liver disease. However, despite decades of vaccination campaigns, millions of new infections are still reported every year. Here, we aimed to assess the nationwide HBV vaccination coverage in Mauritania as well as the presence of protective levels of the antibodies against HBV surface antigen (HBsAb) following vaccination in a sample of children immunized as infants. Methods: To evaluate the frequency of fully vaccinated and seroprotected children in Mauritania, a prospective serological study was conducted in the capital. First, we evaluated the pediatric HBV vaccine coverage in Mauritania between 2015 and 2020. Then, we examined the level of antibodies against HBV surface antigen (HBsAb) in 185 fully vaccinated children (aged 9 months to 12 years) by ELISA using the VIDAS hepatitis panel for Minividas (Biomerieux). These vaccinated children were sampled in 2014 or 2021. Results: In Mauritania, between 2016 and 2019, more than 85% of children received the complete HBV vaccine regimen. While 93% of immunized children between 0 and 23 months displayed HBsAb titer >10 IU/L, the frequency of children with similar titers decreased to 63, 58 and 29% in children aged between 24–47, 48–59 and 60–144 months, respectively. Conclusions: A marked reduction in the frequency of HBsAb titer was observed with time, indicating that HBsAb titer usefulness as marker of protection is short lived and prompting the need for more accurate biomarkers predictive of long-term protection.

Universal Hepatitis B Antibody Screening and Vaccination in Pregnancy: A Cost-Effectiveness Analysis

OBJECTIVE

To evaluate the cost effectiveness of universal screening for hepatitis B immunity and vaccination among pregnant women in the United States.

METHODS

We designed a decision-analytic model to evaluate the outcomes, costs, and cost effectiveness associated with universal hepatitis B virus (HBV) immunity screening in pregnancy with vaccination of susceptible individuals compared with no screening. A theoretical cohort of 3.6 million women, the approximate number of annual live births in the United States, was used. Outcomes included cases of HBV, hepatocellular carcinoma, decompensated cirrhosis, liver transplant and death, in addition to cost and quality-adjusted life-years (QALYs). Model inputs were derived from the literature, and the willingness-to-pay threshold was $50,000 per QALY. Univariate sensitivity analyses and Monte Carlo simulation models were performed to evaluate the robustness of the results.

RESULTS

In a theoretical cohort of 3.6 million women, universal HBV immunity screening and vaccination resulted in 1,702 fewer cases of HBV, seven fewer cases of decompensated cirrhosis, four fewer liver transplants, and 11 fewer deaths over the life expectancy of a woman after pregnancy. Universal screening and vaccination were found to be cost effective, with an incremental cost-effectiveness ratio of $1,890 per QALY. Sensitivity analyses demonstrated the model was robust even when the prevalence of HBV immunity was high and the annual risk of HBV acquisition low.

CONCLUSION

Among pregnant women in the United States, universal HBV immunity screening and vaccination of susceptible persons is cost effective compared with not routinely screening and vaccinating.

Protective immunity against hepatitis B virus infection in a group of vaccinated Sri Lankan military service men following a complete course of vaccination

Vaccination is the appropriate measure to protect military personnel against the hepatitis B virus (HBV) infection. Testing the military personnel for anti-HBs levels after vaccination is vital in re-vaccinating those that have not developed protective immunity. The aim of the current study was to determine the immunity in a group of vaccinated Sri Lankan military personnel (n = 150; age = 26-44 years) following a complete course of hepatitis B virus surface antigen (HBsAg) vaccination by assessing the antibodies against HBsAg (anti-HBs) levels. Three months after the last dose of the vaccination, blood samples were collected from the study population and tested for anti-HBs levels using a commercially available ELISA. Of the 150 military service men tested, 139 (92.67%) had anti-HBs levels higher than 10 mIU/mL, WHO approved levels for protective immunity against HBV infection. Of the 139 that had sufficient anti-HBs levels, 24% (36/150) had anti-HBs levels between 10 and 100 mIU/mL and 68.67% (103/150) had anti-HBs levels > 100 mIU/mL. Overall, 7.33% (11/150) participants had anti-HBs levels < 10 mIU/mL. Sero-conversion to > 10 mIU/mL anti-HBs was more than 90% in those that were less than 40 years of age and it was less than 90% in those that were more than 40 years of age.

Perforation rates in double latex gloves and protective effects of outer work gloves in a postmortem examination room: A STROBE-compliant study

Medical staff face the risk of exposure to blood-borne infectious agents during postmortem examinations. This study investigated the effectiveness of non-slip work gloves worn over 2 layers of surgical latex gloves (outer and inner gloves) as a means of reducing hand and finger injuries. Complete sets of outer and inner gloves worn during postmortem examinations were collected from participating forensic staff. Latex gloves were categorized into 2 groups based on the users' actions during the examination: the wearing group if the wearer wore their work gloves continuously without interruption, and the taking-off group if the wearer removed them at least once. Perforation rates, locations, and shapes were compared between these groups. Outer-glove perforation occurred significantly more often in the taking-off group (n = 102 pairs) than in the wearing group (n = 91 pairs) (30.4% vs 3.8%, P < .001). Inner-glove perforation occurred at rates of 2.0% and 0.5% (P = .38), respectively. The wearers did not incur hand or finger injuries. Perforation rates were similar between the dominant and non-dominant hands (P = .18). Regarding location, gloves were punctured most frequently at the thumb, followed by the index finger. Most examiners (85.6%) did not notice the perforation when the damage occurred. Therefore, we could not confirm that a specific operation within a set of plural operations affected the rate of perforation. Additionally, we could not prove a relationship between glove perforation and each operation performed with/without work gloves. The perforation appearances varied greatly in shape and size, suggesting multiple causes of perforation. The continuous (i.e., uninterrupted) wear of work gloves during postmortem examinations reduced the incidence of perforations in both latex glove layers and thus reduced the risk of hand and finger injury.

Evaluation of immune response to hepatitis B vaccine in healthcare workers at a tertiary care hospital

Purpose

Healthcare workers (HCWs) are at high risk of acquiring hepatitis B virus (HBV) infection through occupational exposure which is preventable through hepatitis B vaccination. In the current study, the response to HBV surface antigen (HBsAg) vaccine was assessed in a selected group of HCWs by testing for antibodies against HBsAg (anti-HBs).

Methods

Blood samples were collected in all HCWs, who have received the complete schedule of hepatitis B vaccination and anti-HBs levels, were assessed quantitatively in sera using ELISA.

Results

The age range of the study participants was 20-55 years. The mean months after the last dose of vaccination were 60.36. Among the 85 participants, 96.5% (n = 82) have protective immunity to hepatitis B. The anti-Hbs response was similar in both male and female (P > 0.05). There was a decline in immune response as the age was increasing (P < 0.05). The results of the study found a significant decline in the immune response with time (P < 0.05). The anti-Hbs response was declined with smoking habit (P < 0.05) and with increasing body mass index (P < 0.05).

Conclusion

Post-HBsAg vaccination immunity to hepatitis B was 96.5% in HCW and was similar to that of global rates. Increasing age, time period, smoking habit, and overweight were associated with decreased immunity. Many studies are needed in developing newer HBV vaccines with very high immunogenicity. Giving highly immunogenic vaccine to HCWs will ensure safety at work by reducing nosocomial transmission which is very much desired in a resource-limited country.

HBV seroprevalence after 25 years of universal mass vaccination and management of non-responders to the anti-Hepatitis B vaccine: An Italian study among medical students

According to international guidelines, healthcare workers and medical students immunized against HBV are periodically tested for anti-HBs IgG. Subjects who show an anti-HBs titre <10 mUI/mL must receive additional vaccine doses to induce a measurable antibody response. This study aimed to evaluate the long-time immunogenicity of anti-hepatitis B vaccination in a sample of medical students and residents of the University of Bari who attended the Hygiene Department for biological risk assessment (April 2014-June 2017). The strategy for the management of nonresponder subjects was evaluated. A total of 3676 students and residents were invited for testing according to a standardized protocol. Anti-HBs IgG was tested for in 3140 (85.4%) subjects: 1174/3140 (37.7%) subjects were negative. 14.6% (128/808) of subjects who received the vaccine during their 12th year of life and 45.8% (1056/2305) of subjects immunized during the first year of life (P < 0.0001) were negative. 1005/1174 (85.6%) seronegative subjects received a booster dose, and 903/1005 (89.9%) were tested for anti-HBs 1 month after the booster dose: 82/903 (9.1%) subjects were still negative. Of these, 56/82 (68.3%) received 2 additional doses of vaccine and 52/56 (92.9%) were tested 1 month after the third dose: 50/52 subjects (96.2%) developed a positive titre. In conclusion, several medical students, immunized at birth or at young age against HBV, did not develop protective titres against the virus. Our management strategy (booster retest; for negative subjects, 2 doses and retest) seems consistent with the purpose of evidencing immunological memory.

Factors Affecting the Development of an Antibody Response to Hepatitis B Immunization in Children With Intestinal Failure: Before and After Small Bowel Transplantation (With and Without Liver Graft)

BACKGROUND

Small bowel transplant with or without a liver graft (SBTx ± LTx) for children with intestinal failure involves checking their immunity to a range of microorganisms, including hepatitis B virus (HBV), at the time of assessment. HBV vaccination in the United Kingdom is recommended for transplant candidates. The aim of this audit was to find out how many SBTx ± LTx candidates received HBV vaccination before transplantation and how the timing of vaccination influenced the development of immunity.

MATERIALS AND METHODS

Retrospective review of case notes and hospital microbiology database formed the basis of the study. Vaccination history and serology were available in 56 of 87 subjects who had SBTx ± LTx.

RESULTS

All patients were seronegative for HBV when assessed for transplant. HBV vaccination was started before transplant in 25 children and after transplant in 31. Eight children died posttransplant before their immunity could be checked, but of the 48 survivors, 20 children developed immunity, of whom 13 (65%) received at least 1 vaccination before SBTx ± LTx ( P = .008). Lack of response to HBV vaccine was significantly associated with isolated bowel transplantation and intensification of immune suppression. Of 11 children, 5 lost hepatitis B surface antibody (HbsAb), and 28 never made HBsAb, despite repeated vaccinations.

CONCLUSION

Our study clearly shows that HBV vaccine before transplant is more effective. In line with renal failure patients, we suggest that children with chronic intestinal failure receive HBV vaccine when clinically stable, before referral for transplant. Higher-dose vaccines, accelerated schedules, and more frequent booster vaccinations are also strategies that may improve HBsAb levels after transplant.

Immune Responses to Single-Dose Versus Double-Dose Hepatitis B Vaccines in Healthcare Workers not Responding to the Primary Vaccine Series: A Randomized Clinical Trial

BACKGROUND

Recommendations to immunize healthcare workers (HCWs) against hepatitis B are well known. However, a proportion of individuals do not respond to the primary standard three-dose HB vaccination schedule.

OBJECTIVES

The current study aimed to evaluate whether a double-dose HB booster vaccine could induce better protective anti-HB titers than a single-dose booster in non-protected HCWs.

MATERIALS AND METHODS

This was a randomized clinical trial. A total of 91 HCWs not responding to the primary vaccine series in 2014 were enrolled. The participants were randomized into two groups that received a double dose of the HB vaccine containing 40 µg of antigen or a single dose of the HB vaccine containing 20 µg of antigen in three doses (at zero, one and six months after vaccination). Blood samples were collected before vaccinations and 28 days after the third dose to assess the seroconversion rate, according to the anti-HB antibody titer threshold of > 10 mIU/mL.

RESULTS

The seroconversion rates were 93.2% and 87.2% after the first booster doses of the double-dose and single-dose HB vaccines, respectively (P = 0.64). In the double-dose HB vaccine group, the seroconversion rate was 97.8% compared with 89.6% in the single-dose group following the second vaccine dose (P = 0.83). All of the participants in both groups were seroprotected after the third HB vaccine dose.

CONCLUSIONS

Both the single- and double-dose HB vaccines were adequately immunogenic, and the double-dose HB vaccine was not significantly more immunogenic than the single-dose vaccine in terms of the seroconversion rates of HCWs who had not responded to the primary vaccine series.

Quality of reporting clinical trials published in five leading Sri Lankan medical journals

OBJECTIVES

To assess the quality of reporting of clinical trials published in five leading Sri Lankan medical journals.

METHODS

Six medical journals were hand searched for clinical trials published from 1982 to 2011. Eligible criteria were all randomized and non-randomized clinical trials conducted in humans. A checklist was developed based on CONSORT and TREND recommendations. Each study was independently evaluated by two reviewers. Outcome measures were presence of checklist items in published reports.

RESULTS

Fifteen randomized and 24 non-randomized parallel group trials from 724 studies in five journals met the inclusion criteria. Out of 39 trials, 39 (97%) clearly described the objectives, 16 (41%) defined the periods of recruitment, 7 (18%) reported how sample size was determined, 10 (25.6%) reported the methods to enhance the quality of measurements, 20 (51%) reported baseline demographic and clinical characteristics of each group, 4 (10%) showed flow diagrams, 23 (69%) reported statistical methods used to compare groups for primary outcomes, 21 (54%) reported effect size, 4 (10%) reported its precision, and 20 (51%) interpreted the results in the context of current evidence, and 5 (13%) described the generalizability of the findings. Of the 15 randomized trials, only one (7%) reported sequence generation, 5 (33%) allocation concealment, 9 (60%) reported blinding status of participants or investigators, and 2 (13%) reported intention to treat analysis.

CONCLUSIONS

Reporting of several essential recommendations remained suboptimal. Education and training of trial methods and awareness of the CONSORT and TREND statements and more attention to the quality of reporting may improve matters.

A chimeric Sindbis-based vaccine protects cynomolgus macaques against a lethal aerosol challenge of eastern equine encephalitis virus

Eastern equine encephalitis virus (EEEV) is a mosquito-borne alphavirus that causes sporadic, often fatal disease outbreaks in humans and equids, and is also a biological threat agent. Two chimeric vaccine candidates were constructed using a cDNA clone with a Sindbis virus (SINV) backbone and structural protein genes from either a North (SIN/NAEEEV) or South American (SIN/SAEEEV) strain of EEEV. The vaccine candidates were tested in a nonhuman primate (NHP) model of eastern equine encephalitis (EEE). Cynomolgus macaques were either sham-vaccinated, or vaccinated with a single dose of either SIN/NAEEEV or SIN/SAEEEV. After vaccination, animals were challenged by aerosol with a virulent North American strain of EEEV (NA EEEV). The SIN/NAEEEV vaccine provided significant protection, and most vaccinated animals survived EEEV challenge (82%) with little evidence of disease, whereas most SIN/SAEEEV-vaccinated (83%) and control (100%) animals died. Protected animals exhibited minimal changes in temperature and cardiovascular rhythm, whereas unprotected animals showed profound hyperthermia and changes in heart rate postexposure. Acute inflammation and neuronal necrosis were consistent with EEEV-induced encephalitis in unprotected animals, whereas no encephalitis-related histopathologic changes were observed in the SIN/NAEEEV-vaccinated animals. These results demonstrate that the chimeric SIN/NAEEEV vaccine candidate protects against an aerosol EEEV exposure.

[Effectiveness of recombinant DNA vaccines against hepatitis B in blood donors in an endemic region of South Brazil]

The objective of this work was to estimate the effectiveness of DNA recombinant anti-HBV vaccines in a retrospective cohort study of 1,012 Brazilian blood donors who completed the vaccination schedule (3 doses + booster of antibody titer < 10IU/L) during the period 1998-2002. The results showed that seroconversion rates were significantly lower among the donors whose antibody titers was measured six months after completing the vaccination scheme and among older donors, particularly those aged over 50. Overall vaccine effectiveness was 88.7%, ranging from 80.6% in the oldest (50 years or over) to 91.4% among the youngest (18-30 years) donors. The booster regimen was effective at reducing the percentage of non-responders. We conclude that vaccine effectiveness was significantly better in younger blood donors and that the anti-HBs testing interval influenced the vaccine effectiveness.

Study of hepatitis B (HB) vaccine non-responsiveness among health care workers from an endemic area (Taiwan)

OBJECTIVE

To evaluate the etiology of non-responsiveness to hepatitis B (HB) vaccination in adults from an endemic area.

METHODS

A total of 250 subjects who were HBsAg negative and anti-HBs<10 mIU/ml received three-dose HB-vaccine series. Anti-HBs 'negative' was defined as a level<1.5 mIU/ml. 'Weakly' positive was defined as 1.5-10 mIU/ml at pre-vaccination testing. Anti-HBs response was defined as a level >10 mIU/ml at post-vaccination testing. Among non-responders who were anti-HBc positive, serum anti-HBe and hepatitis B virus (HBV) DNA were tested.

RESULTS

Three variables were associated with non-responsiveness by univariate analysis: anti-HBc positive, male gender, and age >40 years. Multivariate analysis additionally showed that anti-HBs negative was associated with non-responsiveness. Among 23 non-responders in anti-HBc positive subjects, post-vaccination serum was available in 16 subjects. HBV-DNA in all subjects was under detectable level by PCR assay. Anti-HBe positive were found in 13 of 16 subjects and were assumed to be occult HBV infection.

CONCLUSION

Male gender, age >40 years and anti-HBc positive are associated with non-responsiveness to HB vaccination. Most of non-responders among anti-HBc positive subjects were assumed to be occult HBV infection. Subjects with weakly positive anti-HBs were associated with responsiveness which may be the effect of immune memory.