Evaluation of immune response to Hepatitis B vaccine in health care workers at a tertiary care hospital in Pakistan: an observational prospective study

Evaluation of Immune Characteristics and Factors Associated with Immune Response following Hepatitis B Vaccination among Ghanaian Adolescents

Background

WHO recommends HBV-negative babies in high-prevalence (8%) countries receive anti-HBV vaccination. Ghana initiated mass immunization in 2002, but concerns remain about vaccine effectiveness and long-term protection. We evaluated immune characteristics and factors following hepatitis B vaccination among Ghanaian adolescents who received HBV vaccines.

Methods

In this longitudinal cross-sectional study, 74 participants were enrolled from the Kumasi Metropolis, Ghana. Sociodemographic and lifestyle characteristics of participants were obtained using a questionnaire. Blood samples were obtained before and after booster administration for anti-HBsAg, IL-6, and IL-10 estimations using ELISA kit (Shanghai Chemical Ltd., China). Anti-HBsAg titers ≥10 mIU/ml were considered protective. Statistical analyses were done using SPSS version 26.0 and R programming language, p < 0.05 was considered statistically significant.

Results

We found 100% seroconversion rate, with 25.7% seroprotection rate (anti-HBsAg >10 mIU/ml). Gender (p=0.009), age (p=0.001), and exercising (p=0.044) were significantly associated with seroprotection. Following booster administration, 59.4% were hyporesponders (10 ≤ anti-HBsAg titre ≤99 mIU/ml) whilst 40.6% were good responders (anti-HBsAg titre ≥100 mIU/ml). Exercise (p=0.034) was significantly associated with immune response after booster administration. Moreover, we reported significant positive correlation between cytokines [IL-6 (r = 0.817, p < 0.001) and IL-10 (r = 0.928, p < 0.001)] and anti-HBsAg titre.

Conclusion

Approximately two thirds of adolescents vaccinated at birth lack protective levels of antibodies against hepatitis B virus. Booster vaccines could aid in mounting protective levels of anti-HBsAg. Physical exercise was negatively associated with immune response to hepatitis B vaccinations.

Sex-Differential and Non-specific Effects of Vaccines Over the Life Course

Biological sex and age have profound effects on immune responses throughout the lifespan and impact vaccine acceptance, responses, and outcomes. Mounting evidence from epidemiological, clinical, and animal model studies show that males and females respond differentially to vaccination throughout the lifespan. Within age groups, females tend to produce greater vaccine-induced immune responses than males, with sex differences apparent across all age groups, but are most pronounced among reproductive aged individuals. Females report more adverse effects following vaccination than males. Females, especially among children under 5 years of age, also experience more non-specific effects of vaccination. Despite these known sex- and age-specific differences in vaccine-induced immune responses and outcomes, sex and age are often ignored in vaccine research. Herein, we review the known sex differences in the immunogenicity, effectiveness, reactogenicity, and non-specific effects of vaccination over the lifespan. Ways in which these data can be leveraged to improve vaccine research are described.

Hepatitis B surface antibody levels among health-care personnel vaccinated against hepatitis B in a teaching hospital in South India

Background:

Hepatitis B virus infection is a global health priority, and health-care personnel (HCP) have 10 times higher prevalence than the general population. Seromonitoring identifies those with low titers and vaccine nonresponders with increased risk.

Objective:

The objective of the study was to assess hepatitis B surface antibody (anti-HBs) titers and associated factors among HCP vaccinated against hepatitis B in a teaching hospital in Kerala.

Methods:

A cross-sectional study was done among 454 vaccinated HCP, and anti-HBs antibody titers were assessed by enzyme-linked immunosorbent assay method.

Results:

Participants included 162 (35.7%) doctors, 132 (29.3%) nursing and laboratory personnel, and 160 (35.3%) supporting staff. The mean age was 38.06 ± 11.33 years, and 72% were female. Majority (92.5%, 420) were seroprotected and 78.9% (358) with high (>100 mIU) titers. Moderate (10–100 mIU) and low (<10 mIU) level seroprotection was seen in 13.7% (62) and 7.5% (34), respectively. Incomplete vaccination, >10 years since vaccination, and age >40 years were independent predictors for poor seroprotection, while increasing doses and boosters were positively associated.

Conclusions:

Majority of vaccinated HCP were seroprotected. Incomplete schedules, older age, and prolonged time since vaccination can lead to decline in titers, and periodical seromonitoring should guide hepatitis B revaccination strategies.

Immune response to hepatitis B vaccine following complete immunization of children attending two regional hospitals in the Southwest region of Cameroon: a cross sectional study

BACKGROUND

Hepatitis B virus (HBV) infection despite being a vaccine preventable disease remains a global public health problem. In Cameroon, the hepatitis B vaccine was introduced in the expanded program on immunisation in 2005, but there has been limited evaluation of the HBV surface antibody response post vaccination.

OBJECTIVE

We investigated the immune response to hepatitis B vaccine in infants who received the DPT-Hep B-Hib vaccine, and we assessed HBsAg carriage in non-responders. We also investigated factors associated with non-response or poor response.

METHODS

Using a hospital based cross sectional design and a structured questionnaire over a four-month period (January to April 2019), we collected data to determine factors associated with hepatitis B surface antibody (anti-HBs) response from infants aged 6 to 9 months attending infant welfare clinics (IWC) at the Buea and Limbe regional hospitals. We collected venous blood and measured anti-HBs titres using a quantitative Foresight® ELISA. We entered and analysed data using EpiData version 3.1 and SPSS version 25 respectively.

RESULTS

Of the 161 infants enrolled, 159 (98.8%) developed anti-HBs antibodies. Of these 159, 157 (97.5%) and 117 (72.7%) developed ≥ 10.0 mIU/ml (seroprotection) and ≥ 100.0 mIU/ml anti-HBs titres respectively. Being younger (6 months old) was associated with seroprotection (Cramer V = 0.322, p = 0.001). Spearman rho's relational analysis showed that immunity against HBV reduced as the duration since the last dose increased (r = -0.172; P = 0.029). However, a Firth logistic regression showed no significant association of factors with inadequate immunity. All 12 (7.5%) infants exposed to HBV at birth, received the hepatitis B vaccine at birth, including four who received HBIG, and all were protected. Four infants (2.5%) had anti-HBs titres < 10.0 mIU/mL (non-responders) but had no peculiarity.

CONCLUSION

The seroprotective rate following hepatitis B vaccination of infants is high even in exposed infants. Our study suggests that Cameroon's HBV vaccine in the Expanded Program on Immunisation (EPI) is effective against HBV, although we could not account for the 2.5% non-response rate. Large scale studies are needed to further explore non-response to the vaccine.

Immune response to hepatitis B vaccine: An evaluation

Background:

Hepatitis B virus infection is a major public health problem in India, and all health-care workers (HCWs) need to be immunized to prevent occupational exposure. This study was done to find the hepatitis B vaccination rates, immune response, and predictors of titer <10 mIU/ml among students and HCWs of a tertiary care institution in the state of Kerala.

Materials and Methods:

This was a cross-sectional study conducted in the Department of Microbiology, Government TD Medical College, Alappuzha, Kerala, India, for a period of 1½ years between January 1, 2016, and June 30, 2017. Vaccination rates were collected through a screening proforma. Of the 1321 participants who filled the screening proforma, 5 ml of blood was collected aseptically from 579 participants who were fully vaccinated (all the three doses of vaccine) and stored at −20°C until antibody to hepatitis B surface antigen (anti-HBs) assay was done using Microlisa (Biorad). Data were analyzed using SPSS for Windows, version 16.0. (SPSS Inc., Chicago, IL, USA) (trial version).

Statistical Analysis:

Descriptive data were expressed using frequencies and percentages, and Chi-square test was applied to find the association between antibody titer <10 mIU/ml and independent variables.

Results:

Of the 1321 participants who filled up the screening proforma, the vaccination rate was 72.6%. Majority of the participants, i.e. 83.5% of doctors, 81.1% of nurses, 69.7% of students, and 21.4% of technicians, had taken all the three doses of hepatitis B vaccine. Of the fully vaccinated (n = 959) participants, 76.9% had the vaccination during adulthood and only 26.1% had it during childhood. The correlate of protection was defined as the presence of anti-HBs ≥10 mIU/ml. The mean antibody titer was 448 ± 284.97 mIU/ml ranging from 9.8 to 2000. Of the 579 participants whose titer was checked, 71 (12.3%) had a nonprotective titer of <10 mIU/ml. We found that age >35 (odds ratio [OR]: 3.85, 95% confidence interval [CI]: 2.12–6.99]), last dose >10 years (OR: 5.01, 95% CI: 2.94–8.55), no boosters or revaccination (OR: 2.94, 95% CI: 1.42–6.07), and body mass index (BMI) >25 (OR: 2.51, 95% CI: 1.44–3.39) were associated with nonprotective titer.

Conclusion:

More than a quarter of the study population who were at high risk of exposure were unvaccinated or partially vaccinated. Even after taking the full course of hepatitis B vaccine, 12.3% had titer <10 mIU/ml. Nonprotective titer was found to be associated with age >35 years, last dose taken >10 years ago, no boosters/revaccination, and BMI ≥25.

Prevalence of some hepatitis B virus markers among pregnant women attending antenatal clinic in Specialist Hospital Sokoto Nigeria

BACKGROUND

Hepatitis B virus infection is a global public health problem. The virus has infected more than one-third of the global population. It has been estimated that 360 million chronic carriers are living around the world with a high risk for developing cirrhosis, hepatic carcinoma and hepatic failure.

OBJECTIVE

The aim of this study was to determine the prevalence of some hepatitis B markers among pregnant women attending antenatal clinic in Sokoto Specialist Hospital, Nigeria.

METHODS

The hepatitis testing was carried out using the Skytec-Rapid Diagnostic HBV-5 rapid kit (Skytec-Rapid Diagnostic, USA). The kit is based on lateral flow chromatographic immunoassay for the qualitative detection of HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb in human serum or plasma. Panel format can conveniently test for five targets at once and utilizes all markers to help distinguish between acute and chronic infections.

RESULTS

Out of 117 pregnant women tested, 15 were positive for HBsAg (12.8%), 6 positive for HBsAb (5.1%), 1 for HBeAg (0.9%), 14 tested positive for HBeAb (12.0%), and 14 tested for HBcAb (12.0%). The prevalence of HBsAg, HBsAb, HBeAg, HBcAb and HBcAb was compared based on ethnicity. HBsAb was significantly higher among the Hausa ethnic group (p= 0.001). The prevalence of HBsAb, HBeAg, HBcAb and HBcAb was not affected by ethnicity (p> 0.05). The prevalence of HBsAg, HBsAb, HBeAg, HBcAb and HBcAb was compared based on age. Infection by the hepatitis B virus markers was higher among young adult and middle age groups. The difference was however not statistically significant (p> 0.05). The prevalence of HBsAg, HBsAb, HBeAg, HBcAb and HBcAb was compared based on the educational status, previous history of blood transfusion, jaundice, employment status and previous history of still births among the pregnant subjects. There were no statistically significant differences in the prevalence of Hepatitis B virus markers (p> 0.05).

CONCLUSION

The study observed a high prevalence of various hepatitis B viral markers among pregnant women attending antenatal care in Specialist Hospital Sokoto. There is need for routine screening of all pregnant women and infants born to hepatitis B positive mothers. Government and non-governmental organizations should intensify efforts to enlighten the general population on the public health importance of the disease and the importance of hepatitis screening. There is also need for the development of a treatment protocol for the management of pregnant women positive for hepatitis B to prevent mother to child transmission. There is an urgent need for the implementation of evidenced-based best practice of providing universal vaccination against hepatitis B for all hepatitis B negative women of child bearing age in particular and all Nigerians in general.

Demographics, Biochemical Characteristics, and Phases of Chronic Hepatitis B Virus Infection: Retrospective Analysis From a Secondary Care Setup

Introduction Hepatitis B virus (HBV) is the leading cause of cirrhosis in the developing world. Despite the development of effective vaccine(s) and direct-acting antivirals (DAAs) such as tenofovir and entecavir, the eradication of chronic HBV remains a distant dream in endemic regions. Factors such as treatment naivety, longer duration of disease, late diagnosis, family history of liver disorders and hepatocellular carcinoma, fatty liver disease, multiple comorbidities, alcoholism, use of tobacco products, noncompliance to drugs, and loss to follow-up all contribute to disease progression and development of complications. In order to promote a better understanding of the treatment initiation, duration, and eventual outcomes, the European Association for the Study of the Liver (EASL) updated its guidelines in 2017 and introduced a new staging system for chronic HBV. Since these guidelines are relatively recent, data regarding the new staging is virtually absent in local/regional settings. Moreover, it has been observed that patients presenting to secondary care setups at major urban centers have disease characteristics quite distinct from those of their rural counterparts or patients presenting to tertiary care setups, even in the same cities. Additionally, there is scarce published data with regard to this aspect. With this study, we hope to make progress on all of those fronts. Objective We aimed to evaluate the demographics, biochemical characteristics, and phases of chronic HBV at the secondary care level. Methods This was a retrospective observational cohort conducted at the Sindh Government Hospital, Liaquatabad from January to December 2020. Patients of either gender who were aged ≥12 years, and diagnosed as a case of chronic HBV were eligible to be enrolled in the study. Only treatment-naive patients were enrolled in the study. Demographics, biochemical characteristics, and phases of HBV (in light of the updated guidelines issued by EASL in 2017 with respect to HBV) were recorded and analyzed. Patient confidentiality was ensured at all times. Results A total of 102 patients were enrolled in the study. The mean age of our cohort was 34.31 ±12.42 years, and the male-to-female ratio was 3:2. All referrals were made from within the city district. Housewives and laborers made up the majority of our patients. The mean alanine transaminase (ALT) levels were 39.83 ±21.33 IU/L; otherwise, the biochemical profile of the patients was unremarkable. Phase III was the most frequently recorded stage of chronic HBV; 41 (40.19%) of the patients were diagnosed with it. However, nearly half of the patients had chronic active hepatitis (phases II and IV). Only a single case each of hepatitis Delta virus and decompensated liver disease (DCLD) was recorded. Conclusions All patients of chronic HBV presenting at the secondary care level were referred locally, were relatively older, and exhibited a higher frequency of chronic active hepatitis (phases II and IV). This corresponded to borderline elevations of ALT. But the remainder of the biochemical profile was largely unremarkable due to the very low prevalence of cirrhosis among these patients.

Effectiveness of hepatitis B vaccination in chronic HCV patients after successful generic direct acting antiviral therapy: significance of isolated hepatitis B core antibodies

OBJECTIVE

Previous reports show conflicting results regarding hepatitis B virus (HBV) vaccine efficacy in Hepatitis C virus (HCV) infected individuals and in those with isolated hepatitis B core antibodies (HBcAb). We aimed to evaluate the effectiveness of HBV vaccine and identify possible factors that may contribute to hyporesponsivness in HCV-treated patients, including those with isolated HBcAb.

METHODS

We conducted a prospective study with 118 enrolled chronic HCV patients who followed a 12-week regimen of direct acting antivirals (DAAs) and were evaluated for HBV serological markers. Eventually, 98 received appropriate HBV vaccination and were assessed for response.

RESULTS

A total of 57.1% were vaccine responders although only 5.1% achieved a seroprotective level of HBsAb titre. The response rate was significantly lower among treated HCV patients with isolated HBcAb [2 (5.6%) vs. 40 (64.5%) respectively]. On multivariate analysis, advanced age [OR (95% CI) = 1.09 (1.02-1.17)] and presence of isolated HbcAb [OR (95% CI) = 39.59 (7.98-196.63)] were predictors of vaccine non-response. In our cost-effectiveness models, the cost of HBV serological screening was less than the nationally adopted non-screening approach. A model ratifying reinforced vaccination in non-responder HBcAb seropositive HCV patients would incur extra cost.

CONCLUSION

Hyporesponsiveness to the HBV vaccination is frequent in chronic HCV patients even after achieving SVR following DAAs. Although there is no consensus on the clinical management of patients with isolated HBcAb, our cost-effectiveness options may support decision-making for better clinical benefit and proper health investments.

Are healthcare workers immunized after receiving hepatitis B vaccination according to recommended guidelines? A systematic review and meta-analysis

OBJECTIVES

Nowadays, it is believed that more than 240 million people worldwide are infected with the hepatitis B virus (HBV), associated with irreversible health-related consequences, represented by hepatic failure, cirrhosis, and hepatocellular carcinoma, and already are ranked as 15^th cause of human death around the world.

METHODS

A systematic review and a meta-analysis were performed to evaluate the effectiveness of vaccination and immunization on health professionals against HBV. The review was registered at the PROSPERO database (CRD42017075643). A search for cross-sectional studies was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and in the gray literature. The Effective Public Health Practice Project Modified Scale was used to evaluate the internal quality of the studies included.

RESULTS

A total of 1865 articles were identified after the removal of duplicates. Of these, 790 studies remained after screening the titles and abstracts. Finally, ten studies remained after full-text reading for qualitative analysis, all of which were used in the meta-analysis. A significant difference was found in the vaccine protocol for health professionals immunized against hepatitis B, compared to those not immunized. The risk ratio was 7.37 (95% confidence interval = 3.92-13.83; P < 0.00001).

CONCLUSION

This study showed that the vaccine protocol is effective in immunizing health professionals against hepatitis B.

Impact of sex and gender on COVID-19 outcomes in Europe

BACKGROUND

Emerging evidence from China suggests that coronavirus disease 2019 (COVID-19) is deadlier for infected men than women with a 2.8% fatality rate being reported in Chinese men versus 1.7% in women. Further, sex-disaggregated data for COVID-19 in several European countries show a similar number of cases between the sexes, but more severe outcomes in aged men. Case fatality is highest in men with pre-existing cardiovascular conditions. The mechanisms accounting for the reduced case fatality rate in women are currently unclear but may offer potential to develop novel risk stratification tools and therapeutic options for women and men.

CONTENT

The present review summarizes latest clinical and epidemiological evidence for gender and sex differences in COVID-19 from Europe and China. We discuss potential sex-specific mechanisms modulating the course of disease, such as hormone-regulated expression of genes encoding for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) entry receptors angiotensin converting enzyme (ACE) 2 receptor and TMPRSS2 as well as sex hormone-driven innate and adaptive immune responses and immunoaging. Finally, we elucidate the impact of gender-specific lifestyle, health behavior, psychological stress, and socioeconomic conditions on COVID-19 and discuss sex specific aspects of antiviral therapies.

CONCLUSION

The sex and gender disparities observed in COVID-19 vulnerability emphasize the need to better understand the impact of sex and gender on incidence and case fatality of the disease and to tailor treatment according to sex and gender. The ongoing and planned prophylactic and therapeutic treatment studies must include prospective sex- and gender-sensitive analyses.

Dynamic assessment of economic and environmental performance index and generation, composition, environmental and human health risks of hospital solid waste in developing countries; A state of the art of review

Many studies have been conducted on hospital solid waste management (HSWM) throughout the world, especially developing countries. This interdisciplinary study aims to summarize the available knowledge on the health and environmental risks of hospital solid waste (HSW) and also, develop a dynamic associational assessment among hospital solid waste generation rate (HSWGR), hospital solid waste composition (HSWC), gross domestic product (GDP) per capita, and environmental performance index (EPI) in some developing countries for the first time. The results of this study showed that researchers from India, China, Pakistan, Brazil, and Iran had found more evidence about the health, economic, and environmental issues in HSW than the other developing countries. The literature showed that the highest and lowest reported HSWGR (in national average level) belonged to Ethiopia (6.03) and India (0.24) kg bed ^-1 day^-1, respectively. It has also been shown that all studied countries except Serbia, have higher levels of hazardous waste in their HSWC, based on the WHO's standard. Furthermore, the quantity and quality of HSW in developing countries depend on the service provided by the hospital, type of hospital, HSWM system, and the level of regional economic and culture. The association analysis showed that the EPI and GDP per capita of developing countries were significantly (p-value <0.05) associated with HSWGR, non-hazardous HSW, and hazardous HSW by the Spearman coefficients equal to 0.389, 0.118, -0.118, and 0.122, 0.216, and -0.346, respectively. However, it can be concluded that GDP per capita and EPI have a weak correlation with hazardous HSW and non-hazardous HSW. Moreover, HSW has many hazardous health and environmental risks such as dioxin and furan, that must be controlled and managed through implementing programs and policies based on sustainable development. As a final point, we believed that the present study can be considered to be a guide for future studies on HSWM in developing countries.

Significance of anti-HB levels below 10 IU/L after vaccination against hepatitis B in infancy or adolescence: an update in relation to sex

Hepatitis B vaccination (three-dose series) induces long-term immunity, but it is not uncommon to find antibody levels below 10 IU/L long after vaccination. However, the majority of the subjects with low antibody levels have a prompt response to a booster dose. A population of 10,294 students at Padua University Medical School, who were subjected to hepatitis B vaccination during infancy or adolescence according to the law, was tested for the presence of anti-HBs, usually during the first year of matriculation. Among the students offered a booster dose, 1,030 were vaccinated, and the antibody titre was re-tested. The present research provides further evidence from a larger number of students (1,030) that an anti-HB level higher than 2 IU/L is predictive of a prompt response to a booster. There are also differences related to sex. The results clearly confirm that an antibody titre equal to or greater than 2 IU/L is enough to prompt a response after a booster dose, even several years after the initial vaccination cycle, and to predict effective immune protection. The length of the interval between the booster/post-booster analyses increases the probability of finding a low response to the booster; furthermore, females show a more rapid response to the booster than males. The importance for healthcare workers of measuring the antibody titre four weeks after a booster is highlighted, and the results suggest that females have a better response than males to booster vaccination.

Knowledge, attitude, and practice study on hepatitis B among medical and nursing undergraduate students of an apex healthcare institute at Uttarakhand foothills: A descriptive analysis

BACKGROUND

Viral hepatitis is preventable, yet a global health priority. As hepatitis B (Hep B) remains an occupational risk for healthcare workers (HCWs), the Government of India recently mandated universal adult Hep B vaccination for all HCWs. However, in the absence of institutional policy, its real-time utilization in a hospital was dependent on individual's general awareness. Therefore, this study was designed to assess baseline knowledge, attitude, and practices among undergraduate medical and nursing students, the future HCWs, regarding Hep B at an apex healthcare institute at Uttarakhand.

MATERIALS AND METHODS

A descriptive survey was carried out using self-administered questionnaire among undergraduate medical and nursing students of a medical college between July and September 2018. Statistical Package for Social Sciences (SPSS Ver 22.0) was used for analysis.

RESULTS

The study comprised 180 medical and 183 nursing students. About 55.0% of medical and 33.9% of nursing students were correctly aware about the disease; 98.3% of medical and 86.9% of nursing students were aware about vaccine. About 80.6% of medical and 87.4% of nursing students showed positive attitude, recognizing disease as a public health problem. However, only 82.8% of medical and 70.0% of nursing students underwent vaccination; mere 62.4% and 49.2% of vaccinated completed three-dose vaccination schedule, respectively. Furthermore, around 7% of them checked their titer post vaccination.

CONCLUSION

Despite comparatively low awareness level about the disease, most students had sufficiently high knowledge about vaccine and underwent vaccination. However, only half of them could complete three-dose vaccination schedule. Only a handful of subjects underwent post-vaccination titer assessment, an instrumental approach to safeguard them against accidental Hep B exposure.

Contribution of sex‑based immunological differences to the enhanced immune response in female mice following vaccination with hepatitis B vaccine

Hepatitis B virus (HBV) vaccination is regarded as the most economical and effective method for the prevention and control of HBV infection, a major global health problem. Previous studies have suggested that there may be sex‑specific differences regarding the immune response to the HBV vaccine in humans; however, the mechanisms associated with these sex‑specific differences are yet to be elucidated. In the present study, sex‑based immunological differences in mice following HBV vaccination were investigated to determine the mechanisms underlying sexual dimorphism, with the aim of identifying potential targets for clinical intervention. Balb/c mice (n=6) were vaccinated intramuscularly on 3 different days (days 0, 14 and 28) with the HBV vaccine. Sera were analyzed via ELISA for the presence of HBV surface antigen (HBsAg)‑specific immunoglobulin G (IgG), and of different IgG subtypes, 3 weeks following the third injection. Enzyme‑linked immunosorbent spot assays were conducted to determine interleukin‑4/interferon‑γ secretion. Immunological memory stimulated by the vaccine was detected via flow cytometry analysis and ELISA 1 week following the booster immunization. The seroconversion of the treated female group was higher compared with the male group at one week following the second vaccination. Female mice exhibited significantly increased HBsAg antibody titers compared with males at 1‑5 weeks following the third vaccination. Sera obtained from vaccinated female mice exhibited markedly increased titers of IgG1 and IgG2b compared with those from male mice. Furthermore, female mice exhibited elevated cytotoxic T lymphocyte responses and immune memory. Collectively, the results of the present study indicated that sex‑based immunological differences affected the dynamics and characteristics of the immune response in mice immunized with the HBV vaccine.

Factors That Influence the Immune Response to Vaccination

There is substantial variation between individuals in the immune response to vaccination. In this review, we provide an overview of the plethora of studies that have investigated factors that influence humoral and cellular vaccine responses in humans. These include intrinsic host factors (such as age, sex, genetics, and comorbidities), perinatal factors (such as gestational age, birth weight, feeding method, and maternal factors), and extrinsic factors (such as preexisting immunity, microbiota, infections, and antibiotics). Further, environmental factors (such as geographic location, season, family size, and toxins), behavioral factors (such as smoking, alcohol consumption, exercise, and sleep), and nutritional factors (such as body mass index, micronutrients, and enteropathy) also influence how individuals respond to vaccines. Moreover, vaccine factors (such as vaccine type, product, adjuvant, and dose) and administration factors (schedule, site, route, time of vaccination, and coadministered vaccines and other drugs) are also important. An understanding of all these factors and their impacts in the design of vaccine studies and decisions on vaccination schedules offers ways to improve vaccine immunogenicity and efficacy.

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.

Age-related immunogenicity and reactogenicity of live oral cholera vaccine CVD 103-HgR in a randomized, controlled clinical trial

Aging is accompanied by a decline in immune function which can lead to decreased responses to vaccines. Attenuated recombinant Vibrio cholerae O1 vaccine strain CVD 103-HgR elicits a rapid serum vibriocidal antibody (SVA) response and protects against cholera diarrhea in volunteer challenge studies but has not been studied in older adults. We evaluated CVD 103-HgR (PXVX0200) in adults age 46-64, compared them to previously studied adults age 18-45, and studied age-related immunogenicity across adults 18-64 years of age. Volunteers were randomized to receive a single dose of 1 × 10⁹ CFU of PXVX0200 or placebo. Immunogenicity endpoints included SVA and anti-cholera toxin (CT) antibody levels on days 1, 11, 29, 91 and 181 and lipopolysaccharide (LPS) and CT-specific IgA and IgG memory B cells on days 1, 91 and 181. Safety was assessed by comparing solicited signs and symptoms on days 1-8 and other adverse events through day 181. 2979 volunteers received vaccine, including 291 age 45-64. Day 11 seroconversion occurred in 90.4% of older adults vs 93.5%% of younger adults and met the endpoint of demonstrating non-inferiority between the two groups. Significant increases in LPS-specific IgG and IgA and CT-specific memory IgG memory B cells were seen at days 91 and 181. There appeared to be a continuous age-related decline in SVA seroconversion and geometric mean titers, but not memory B cell responses, across the 18-64 year age range. Most reactogenicity was mild and was more common in the placebo group. PXVX0200 appears safe and immunogenic in older adults. Clinical Trials Registration: clinicaltrials.gov NCT02100631.

Hepatitis B vaccination coverage among healthcare workers at a tertiary hospital in Rwanda

OBJECTIVE

We evaluated post-vaccination immunity status and describe potential risk factors associated with the lack of response among healthcare workers (HCWs) at a tertiary care hospital in Kigali, Rwanda.

RESULTS

Of 373 HCWs, 291 (78.2%) were female and 81 (21.8%) were male. The mean age of the study participants was 40.2 years (standard deviation [SD], 7.7 years), within a range of 24-41 years. Participants' mean BMI was 25.4 ± 6.6 kg/m², with more than half of patients (60.3%) being overweight. 96% received all three doses of vaccination. A total of 36 participants (9.6%) were considered non responders as they did not develop a sufficient anti-HBs response post vaccination. The anti-HBs response was significantly higher in females when compared to males (p = 0.02). Interestingly, there was no significant association between decline in antibody levels with age (p = 0.242) and BMI (p = 0.516) of the participants. The anti-HBs titers were similar in the group of participants who had received two doses and those who had received three doses of the HBV vaccination. Overall the findings of our study provide a basis for testing for anti-HBs in all HCWs post vaccination in Rwanda.

Pre-travel counseling for immunocompromised travelers: A 12-year single-center retrospective review

BACKGROUND

Immunocompromised travelers (ICTs) are medically complex and challenging for travel medicine providers. Our study hypothesizes that ICTs have high-risk travel itineraries and do not have adequate immunity against vaccine-preventable infections.

METHODS

This retrospective review of 321 ICTs from 2004 to 2015 included patients with solid organ transplant (SOT, n = 134), connective tissue disease (CTD, n = 121), inflammatory bowel disease (IBD, n = 46), and human immunodeficiency virus (HIV, n = 20). Variables included immunosuppressive medications, hepatitis A and B vaccination and serology, gamma-globulin use, and antimalarial and antidiarrheal prophylaxis. Chi-square analysis was used for categorical variables and Kruskal-Wallis for continuous variables.

RESULTS

Malaria-endemic regions accounted for 38.9% (125/321) of travel destinations. High-risk activities were planned by 37.4% (120/321) of travelers. A significant proportion of HIV patients [70.0% (14/20)] visited friends and relatives, whereas other ICTs traveled for tourism. Hepatitis A and B vaccination rates were 77.3% (248/321) and 72.3% (232/321). Post-vaccination hepatitis A and B serologic testing were completed by 66.1% (41/62) and 61.1% (11/18) of travelers, respectively.

CONCLUSION

ICTs demonstrate differences in travel patterns and risk. Serologic testing was uncommon, and vaccination rates were low. Providers should screen ICTs early for upcoming travel plans and advise vaccine completion prior to departure.

Sex and Gender Differences in the Outcomes of Vaccination over the Life Course

Both sex (i.e., biological differences) and gender (i.e., social or cultural influences) impact vaccine acceptance, responses, and outcomes. Clinical data illustrate that among children, young adults, and aged individuals, males and females differ in vaccine-induced immune responses, adverse events, and protection. Although males are more likely to receive vaccines, following vaccination, females typically develop higher antibody responses and report more adverse effects of vaccination than do males. Human, nonhuman animal, and in vitro studies reveal numerous immunological, genetic, hormonal, and environmental factors that differ between males and females and contribute to sex- and gender-specific vaccine responses and outcomes. Herein, we address the impact of sex and gender variables that should be considered in preclinical and clinical studies of vaccines.

Safety, efficacy and pharmacodynamics of vesatolimod (GS-9620) in virally suppressed patients with chronic hepatitis B

BACKGROUND & AIMS

Vesatolimod (GS-9620) is an oral agonist of toll-like receptor 7, an activator of innate and adaptive immune responses. Herein the safety and efficacy of vesatolimod is assessed after once-weekly treatment in patients with chronic hepatitis B (CHB) infection suppressed on oral antiviral treatment.

METHODS

In a phase II, double-blind, randomized, placebo (PBO)-controlled study, 162 patients stratified by hepatitis B surface antigen (HBsAg) levels and serum hepatitis B e antigen (HBeAg) status were randomized 1:3:3:3 to once-weekly oral PBO or vesatolimod (1-, 2-, or 4-mg doses) for 4, 8 or 12 weeks per cohort. Efficacy was assessed by change in baseline HBsAg (log₁₀ IU/ml) at the primary endpoint (Week 24). Safety assessments included adverse events (AE) and laboratory abnormality monitoring. Pharmacodynamic assessments included peripheral cytokine level quantification and interferon-stimulated gene (ISG) mRNA expression evaluation.

RESULTS

The majority of patients were male (76%) and HBeAg-negative (79%) at baseline. Most (41-80%) experienced ≥1 AE during the study with the majority of AEs mild or moderate in severity. No significant declines in HBsAg were observed at the primary (Week 24) or secondary endpoints (Weeks 4, 8, 12, and 48). ISG15 induction was dose-dependent and consistent after repeat dosing, returning closer to baseline by one week after treatment at all dose levels; no patient demonstrated significant serum interferon alpha (IFNα) expression at any timepoint evaluated. Multivariate analyses showed that ≥2-fold ISG15 induction is associated with 2- or 4-mg vesatolimod dose and female sex.

CONCLUSIONS

Vesatolimod was safe and well-tolerated in patients with CHB, demonstrating consistent dose-dependent pharmacodynamic induction of ISG15 without significant systemic induction of IFNα expression or related symptoms. However, no significant HBsAg declines were observed.

LAY SUMMARY

In a phase II study, vesatolimod, an oral, once-weekly, experimental immune-activating drug for the treatment of hepatitis B virus (HBV), is safe and well-tolerated in chronic HBV patients who are virally suppressed on oral antiviral treatment. Despite demonstrating on-target biomarker responses in patients, no significant declines in hepatitis B surface antigen were observed. Clinical Trial Number: GS-US-283-1059; NCT 02166047.

Nursing students: A vulnerable health-care worker for needlesticks injuries in teaching hospitals

Background:

Occupational exposure to bloodborne pathogen is a significant risk to health-care workers. In any teaching hospital apart from regular health-care workers and employees, there are significant population of students and trainee. It is important to assess the health-care worker in hospital which has maximum chances of exposure to these pathogens. The aim of this study is to determine the most susceptible job group for needlestick injury (NSI) reported in a newly established teaching medical institute in the Western part of Rajasthan, India.

Methods:

This is a retrospective analysis of data of NSI occurred during September 2014 to January 2017.

Results:

Sixty three NSIs were reported during the study. Nursing students were the most vulnerable group who reported maximum number of NSI. Among the nursing students, 72% were completely vaccinated against hepatitis B virus.

Conclusions:

Nursing students are at utmost risk for NSIs, the prevention of which requires regular training and education.

Decrease in Anti-HBs Antibodies over Time in Medical Students and Healthcare Workers after Hepatitis B Vaccination

Background

Hepatitis B is one of the most important occupational hazards among healthcare workers (HCWs). This study aimed to measure the anti-HBs titres among the medical students and HCWs vaccinated against hepatitis B virus and to determine the association between anti-HBs levels and time since vaccination.

Materials and Methods

In this cross-sectional study, medical students and healthcare workers who had received all three doses of hepatitis B vaccination and completed at least six months after vaccination since the last dose were included. 3 ml blood was collected from subjects (n = 340) and anti-HBs titre was estimated using ELISA.

Results

A total of 340/400 subjects were aged between 18 and 60 years; 204 were females and 136 males. The median and interquartile range for time since vaccination were 5 and 5 years, respectively. Duration since vaccination was ≤5 years in 223 (65.5%), 6–10 years in 84 (24.7%), and >10 years in 33 (9.70%); among them, antibody titres were >10 mIU/ml in 94.1%, 79.7%, and 72.7% subjects, respectively. There was significant decline in antibody titres as duration of postvaccination increased.

Conclusion

The proportion of subjects who were unprotected after 5 and 10 years after vaccination were 20% and 27%, respectively. The need for a booster dose can be made mandatory at least for healthcare professionals.

A cross-sectional sero-survey on preoperative HBV vaccination policy in Poland

BACKGROUND

A two-dose preoperative vaccination schedule against HBV has been the widely accepted policy in Poland. However, its effectiveness has not yet been assessed.

OBJECTIVE

To evaluate a two-dose preoperative HBV vaccination policy by an assessment of the proportion of patients who don't present a protective level of anti-HBs (<10.0 mIU/ml).

METHODS

Consecutive patients from surgical/gynecologic wards of 12 randomly selected hospitals in West Pomerania, Poland, hospitalized between 2010 and 2013, vaccinated against HBV with a two-dose regimen, were asked to complete an anonymous questionnaire. Serum samples were assayed for anti-HBs with the use of third-generation testing methods. To compare sensitivity versus specificity across a range of values for the ability to predict a dichotomous outcome (a protection against HBV infection) a Receiver operating characteristic (ROC) curve was determined.

RESULTS

There were 193 patients, 58.5% women, median age 52 years. Almost a half (46.0%) of the patients were operated on within 0-60 days of taking the second vaccine dose, 16.2% - 61-180 days after, 37.8% >180 days after. Anti-HBs titer was below a protective level in 49.2% of participants (0.0 mIU/ml in 17.8%, 0.1-9.9 mIU/ml in 31.4%); none of them were aware of this fact. Age ≤ 52 years (OR = 1.89) and having surgery more than 37.5 days after HBV vaccination (OR = 2.70) were associated with greater odds of being protected against HBV infection through vaccination. For the time frame between the second dose implementation and surgery 23 days, a sensitivity of 84% and specificity of 22% for obtaining protection against HBV infection was found, for the time frame >37.5 days - sensitivity remained high (80%), while specificity increased (41%); there was an apparent peek on the ROC curve between 38 and 60 day. In the group vaccinated 0-37.5 days before surgery, less patients had the protective level of anti-HBs titer than in vaccinated 38-60 days before surgery (32.3% vs 60.0%; p = 0.03).

CONCLUSIONS

The success rate in achieving adequate immune protection with two dose HBV vaccination schedule in preoperatively vaccinated patients is relatively low, especially among those vaccinated less than five weeks prior to surgery. In more than a third of cases the standard three-dose regimen could have been implemented, as participants had time to complete a third dose. Current recommendations regarding a preoperative policy with a 2-dose vaccination schedule in Poland should be revised; the best time to perform surgery after the implementation of the second dose of vaccine in the context of patient protection against HBV infection would be between 38 and 60 days.

Age-Period-Cohort Analysis of Liver Cancer Mortality in Korea

BACKGROUND

Liver cancer is one of the most common causes of death in the world. In Korea, hepatitis B virus (HBV) is a major risk factor for liver cancer but infection rates have been declining since the implementation of the national vaccination program. In this study, we examined the secular trends in liver cancer mortality to distinguish the effects of age, time period, and birth cohort.

MATERIALS AND METHODS

Data for the annual number of liver cancer deaths in Korean adults (30 years and older) were obtained from the Korean Statistical Information Service for the period from 1984-2013. Joinpoint regression analysis was used to study the shapes of and to detect the changes in mortality trends. Also, an age-period-cohort model was designed to study the effect of each age, period, and birth cohort on liver cancer mortality.

RESULTS

For both men and women, the age-standardized mortality rate for liver cancer increased from 1984 to 1993 and decreased thereafter. The highest liver cancer mortality rate has shifted to an older age group in recent years. Within the same birth cohort group, the mortality rate of older age groups has been higher than in the younger age groups. Age-period-cohort analysis showed an association with a high mortality rate in the older age group and in recent years, whereas a decreasing mortality rate were observed in the younger birth cohort.

CONCLUSIONS

This study confirmed a decreasing trend in liver cancer mortality among Korean men and women after 1993. The trends in mortality rate may be mainly attributed to cohort effects.

Factors influencing immunologic response to hepatitis B vaccine in adults

Hepatitis B was still a worldwide health problem. This study aimed to conducted a systematic review and meta-analysis to assess a more precise estimation of factors that influence the response to hepatitis B vaccine in adults. Our included studies examined seroprotection rates close to the end of vaccination schedules in healthy adult populations. This meta-analysis including 21053 adults in 37 articles showed that a significantly decreased response to hepatitis B vaccine appeared in adults (age ≥ 40) (RR:1.86, 95% CI:1.55–2.23), male adults (RR:1.40, 95% CI:1.22–1.61), BMI ≥ 25 adults (RR:1.56, 95% CI:1.12–2.17), smoker (RR:1.53, 95% CI:1.21–1.93), and adults with concomitant disease (RR:1.39, 95% CI:1.04–1.86). Meanwhile, we further found a decreased response to hepatitis B vaccine appeared in adults (age ≥ 30) (RR:1.77, 95% CI:1.48–2.10), and adults (age ≥ 60) (RR:1.30, 95% CI:1.01–1.68). However, there were no difference in response to hepatitis B vaccine both in alcoholic (RR:0.90, 95% CI:0.64–1.26) and 0-1-12 vs. 0-1-6 vaccination schedule (RR:1.39, 95% CI:0.41–4.67). Pooling of these studies recommended the sooner the better for adult hepatitis B vaccine strategy. More vaccine doses, supplemental/additional strengthening immunity should be emphasized on the susceptible population of increasing aged, male, BMI ≥ 25, smoking and concomitant disease. The conventional 0-1-6 vaccination schedule could be still worth to be recommended.

Prevalence of non-responsiveness to an indigenous recombinant hepatitis B vaccine: a study among South Indian health care workers in a tertiary hospital

BACKGROUND AND AIM

Health care workers (HCW) are at higher risk of contracting HBV infection. Non-response to HBV vaccine is one of the major impediments to prevent healthcare associated HBV infection (HAHI). We estimated the prevalence of non-responsiveness to initial 3-dose regimen of an indigenous recombinant HBV vaccine (GeneVac-B) among South Indian HCWs and typed the HLA in non-responders.

STUDY DESIGN AND METHOD

Of the 778 subjects screened over 1 year, 454 completed all three doses of the hepatitis B vaccination. Anti-HBs titers were estimated by microparticle enzyme immunoassay AxSYM AUSAB, (Abbott, Germany). HLA typing was done using SSP-PCR assay AllSet+™ Gold SSP (Invitrogen, USA).

RESULTS

The overall seroconversion rate (anti-HBs>10 mIU/mL) was 98.89% wherein 90.8% had titers>1000mIU/mL, 7.6% had titers 100-1000mIU/mL, 0.43% had titers<100 mIU/mL and 1.1% were non-responsive (<10 mIU/mL) to the initial 3-dose regimen. Antibody titers<1000 mIU/mL were significantly associated with the highest quartile of body mass index (BMI) (P<0.001). We found no significant difference in seroprotection rate between gender (P=0.088). There was no difference in seroprotection rates among various ethnic groups (P=0.62). Subjects who were non-responsive in our study had at least one HLA allele earlier known to be associated with non-responsiveness to the vaccine.

CONCLUSION

Our findings suggest that non-response to HBV vaccine is not a major impediment to prevent HAHI. Robust seroprotection rates can be achieved using this indigenous HBV vaccine. However, gender and BMI might influence the level of anti-HBs titers. We recommend the use of this cost effective HBV vaccine as well as postvaccination anti-HBs testing to prevent HAHI among HCWs.

Post-vaccination Immunity Against Hepatitis B Virus and Predictors for Non-responders Among Medical Staff

BACKGROUND

Hepatitis B virus (HBV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). HB vaccination is an essential step in the prevention of the disease and its consequent complications.

OBJECTIVES

Immune status of medical personnel in teaching hospitals of Khuzestan is not well known. Since these personnel are usually at risk of needle stick and other high-risk events, some challenges exist in infection control committee with regard to managing these events. This study was conducted to assess post-vaccination immunity status and non-response to HBV vaccine as well as its predictors among medical staff in a teaching hospital affiliated to Ahvaz Jundishapur University of Medical Sciences (AJUMS) in Ahvaz, southwest Iran.

PATIENTS AND METHODS

In this retrospective cross-sectional study, the medical staff of a teaching hospital was evaluated for their immune response against HBV and factors affecting it. The study conducted in Razi Hospital, Ahvaz City, southwest of Iran, in 2013. Demographical, clinical, and laboratory data registered in medical files of hospital staff were analyzed by SPSS software version 16 using chi-square and Fisher exact tests. Differences with P value < 0.05 were considered significant. To identify predictors for non-responders, we used odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Out of 239 participants, 43 (18 %) were men and 196 (82%) were women. Their mean age was 31.9 ± 18.1 years (range of 20 - 55 years). Fourteen (5.9%) participants were non-responders, 37 (15.5%) were poor responders, and 188 (78.6%) were good responders. The non-responders were older (> 50 years) than the responders (P = 0.0001), while the body mass index (BMI) was not significantly different (P = 0.37) between them. Diabetes mellitus (DM) (OR: 7.3, 95% CI, 1.3 - 41.7, P = 0.05), and using immunosuppressive drugs (ISD) (OR: 3.2, 95% CI, 1.1 - 11.5, P = 0.03) were two variables in association with non-response to HB vaccine.

CONCLUSIONS

Non-response rate to HB vaccine in our study was approximately 6%. Age over 50 years, DM, and receiving immunosuppressive drugs may be considered as predictors for non-response to HB vaccine in medical staff.

Prevalence of hepatitis B virus infection among barbers and their knowledge, attitude and practices in the district of Sukkur, Sindh

OBJECTIVES

Several occupations in developing countries lag behind in ensuring the safety of their workers in occupational settings. Lack of implementation of safety guidelines at workplaces can expose workers to health risks. In Pakistan, barbers are one of the un-regulated occupational groups. Low literacy, increased frequency of direct skin contact and blade/razors use can expose barbers to body fluids including blood of the customers. We conducted this study in order to determine hepatitis B virus (HBV) prevalence among barbers and their knowledge, attitude and practices in a peri-urban district of Sindh.

MATERIAL AND METHODS

Three hundred eighty-five barbers from the Sukkur district were interviewed using a structured questionnaire. Blood samples were collected and tested for HBsAg. A scale was built to determine the proportions of responses to knowledge, attitude and practice items.

RESULTS

The prevalence of HBV among barbers was 2.1%. The barbers' knowledge on HBV and its transmission routes was poor. The response to attitude items was good, except that only 35.1% of the participants agreed to have vaccination against HBV. The overall performance on the knowledge and practice scales was poor compared to the attitude scale on which 80% of the barbers performed well.

CONCLUSION

The prevalence of HBV among barbers was lower compared to the available national figures for the prevalence among the general population.

A reinvestigation of seroconversion rates in hepatits B-vaccinated individuals

The purpose of this study was to examine whether the hepatitis B seroconversion rates in a small sample of subjects reflected that of the published rates, regardless of HIV status, after a hepatitis B vaccination series was completed while following strict vaccine protocols. The study, which had a nonexperimental, correlational cross-sectional design, took place at a community clinic in Laguna Beach, CA. Participants comprised 100, predominantly White, men aged 18-65 years (mean 39.2 years) who were hepatitis B naive, regardless of immune status. After receiving a primary vaccine series for hepatitis B, participants were tested for seroconversion to immune status. Seroconversion to the immune state occurred in 78.6% of the non-immunocompromised, HIV-negative participants (n = 50), who had received the standard three-dose regimen of the vaccine, and in 77% of the immunocompromised, HIV-positive participants (n = 48), who had received the recommended modified three-double-dose regimen. The manufacturer-published rates of seroconversion are 90-100%, depending upon the population. These findings highlight a need for further study to validate or reveal deficits in current vaccine protocols for individuals who are vaccinated against hepatitis B, including health care workers, the immune-compromised and other high-risk populations.

Serologic Hepatitis B Virus Immunity in Health Care Workers

Health care workers (HCWs) are at high risk of blood borne infections including Hepatitis B virus (HBV) infection. HBV vaccination is recommended for HCWs but post vaccination testing of immune response (anti-HBs) is not routinely performed. In our study information on immune response after the first immunization schedule of HCWs is not available. By reason of the questions regarding long lasting immunity, we decided to assess the anti-HBs of HCWs who wished to check immune response after different times of vaccination and also unvaccinated persons in St. Marina University Hospital, Varna, Bulgaria. After informed consent, 341 HCWs were investigated. They were divided into 3 groups according to their status: Group A had no history of vaccination against HBV, Group B had no complete vaccination schedule and Group C had complete vaccination data. Of Group C, 32 had been vaccinated more than 10 years previously, 111 - 10–5 years previously and 48 - < 5 years previously. Quantitative detection of antibody to HBsAg (anti-HBs) by commercial ELISA was carried out. A total, positive immune response was detected in 35.6% (group A), 66.2% (group B) and 80.1% (group C) of HCWs investigated. Of Group C positive immune response was detected in 68.7%, 81.1% and 85.4% respectively of the time of vaccination. Detectable anti-HB was found in HCWs without HBV immunization, probably after unknown exposure to HBV. The lack of information regarding immune response after the first immunization schedule makes the interpretation of no detectible anti-HBs level 5–10 years post-immunization difficult. For the HCWs with anti-HBs loss, counseling for booster vaccine dose and consequent testing is mandatory.

Immune response to hepatitis B vaccine in a group of health care workers in Sri Lanka

Health care workers (HCWs) are considered at high risk of acquiring the hepatitis B virus (HBV). Seroconversion rates after vaccination against HBV among HCWs have not previously been available in Sri Lanka. 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). This was a retrospective descriptive study to measure the anti-HBs levels, using an ELISA, in an immunized group of HCW referred to Department of Microbiology, Faculty of Medicine, University of Peradeniya, Sri Lanka. Among the 342 participants, 9.9% (n=34) were non-responders. Female participants had a significantly higher immune response (94.7%) than males (p<0.05). The results of the study found no significant decline in the immune response with time (p > 0.05). Post HBsAg vaccination immunity in HCW in Sri Lanka is similar to that of global rates with similar gender variation. Anti-HBs levels should be tested in all HCW following HBsAg vaccination so that necessary precautions can be taken.

Nationwide seroepidemiology of hepatitis B virus infection in South Korea in 2009 emphasizes the coexistence of HBsAg and anti-HBs

Hepatitis B virus (HBV) infection is the major cause of chronic liver disease in Korea. This study investigated the seroprevalence of HBV infection with an emphasis on the coexistence of hepatitis B surface antigen (HBsAg) and antibody (anti-HBs). In all, 290,212 people undergoing health check-up examinations in 29 institutions during 2009 were recruited. The crude seroprevalences of HBsAg and anti-HBs was adjusted by age, sex, and geographic area using the 2009 estimated population of Korea. The adjusted seroprevalences of HBsAg and anti-HBs was 4.0% and 73.5%, respectively. Males showed higher HBsAg positivity and lower anti-HBs positivity than females (P<0.001). HBsAg positivity increased with age from 3.5% in people 20-29 years old to 4.8% in people 40-49 years old, followed by a decrease in people ≥ 50 years old. HBsAg positivity in Southern provinces (4.5%) including Jeju (5.9%), was significantly higher than that in Central provinces (3.6%; P<0.001). Interestingly, HBsAg and anti-HBs coexisted in 0.1% of the total subjects and in 2.9% of the HBsAg-positive group, showing distinct age distribution and higher alanine aminotransferase levels than those of the group positive for only HBsAg. In conclusion, the seroprevalence of HBsAg and anti-HBs in Korea varies significantly by age, sex and geographical location and coexisted in 2.9% of HBsAg-positive subjects. Continuous monitoring of seroepidemiology may facilitate the eventual eradication of HBV infection.

Sex differences in prophylaxis and therapeutic treatments for viral diseases

The intensity and prevalence of viral infections are typically higher in males than in females. In contrast, disease outcome can be worse for females. Males and females also differ in their responses to prophylaxis and therapeutic treatments for viral diseases. In response to vaccines against herpes viruses, hepatitis viruses, influenza viruses, and others, females consistently mount higher humoral immune responses and experience more frequent and severe adverse reactions than males. Males and females also differ in the absorption, metabolism, and clearance of antiviral drugs. The pharmacological effects, including toxicity and adverse reactions, of antiviral drugs are typically greater in females than males. The efficacy of antiviral drugs at reducing viral load also differs between the sexes, with antiviral treatments being better at clearing HIV and hepatitis C virus in females, but showing greater reduction of herpes simplex virus and influenza A virus loads in males. Biological variables, including hormone and genes, as well as gender-specific factors related to access and compliance to drug regimens must be considered when evaluating male-female differences in responses to treatments for viral diseases. Clinicians, epidemiologists, and basic biomedical scientists should design experiments that include both males and females, develop a priori hypotheses that the sexes will differ in their responses to and the outcome of vaccines and antiviral treatments, and statistically analyze outcome data by sex. Knowledge that the sexes differ in response to prophylaxis and therapeutic treatments for viral diseases should influence the recommended course of treatment differently for males and females.

Antibody and immune memory persistence post infant hepatitis B vaccination

OBJECTIVES

This study aimed to evaluate the level of hepatitis B immunity among undergraduate students 23 years after commencement of the nationwide hepatitis B childhood immunization program in Malaysia.

METHODS

A total of 402 serum samples obtained from volunteer undergraduate students were screened for the presence of hepatitis B surface antibodies using qualitative ELISA.

RESULTS

Results showed that 62.7% of volunteers had protective anti-hepatitis B surface antigens (≥10 IU/L), of whom 67.9% received three doses of the vaccine. The estimated post-vaccination immunity was found to be at least 20 years, indicating persistent immunity against hepatitis B and a significant association (P < 0.05) with duration of vaccination. Anamnestic response 1 month post-hepatitis B booster was 94.0% and highly significant (P < 0.01). Isolated antihepatitis B core antigen (anti-HBc) prevalence was found to be 5.0%, all having had a positive anamnestic response.

CONCLUSION

Immunity after primary vaccination with hepatitis B recombinant vaccine persists for at least 20 years post-vaccination, with significant association with the number of vaccinations. Furthermore, the presence of anamnestic response to booster vaccine indicates long-lasting immunity despite decreasing antibody levels; therefore, the need for hepatitis B vaccine boosters may not be of significant benefit after complete infant vaccination.

Immune interference in the setting of same-day administration of two similar inactivated alphavirus vaccines: eastern equine and western equine encephalitis

We compared the effect on primary vaccination plaque-reduction neutralization 80% titers (PRNT80) responses of same-day administration (at different injection sites) of two similar investigational inactivated alphavirus vaccines, eastern equine encephalitis (EEE) vaccine (TSI-GSD 104) and western equine encephalitis (WEE) vaccine (TSI-GSD 210) to separate administration. Overall, primary response rate for EEE vaccine was 524/796 (66%) and overall primary response rate for WEE vaccine was 291/695 (42%). EEE vaccine same-day administration yielded a 59% response rate and a responder geometric mean titer (GMT)=89 while separate administration yielded a response rate of 69% and a responder GMT=119. WEE vaccine same-day administration yielded a 30% response rate and a responder GMT=53 while separate administration yielded a response rate of 54% and a responder GMT=79. EEE response rates for same-day administration (group A) vs. non-same-day administration (group B) were significantly affected by gender. A logistic regression model predicting response to EEE comparing group B to group A for females yielded an OR=4.10 (95% CL 1.97-8.55; p=.0002) and for males yielded an OR=1.25 (95% CL 0.76-2.07; p=.3768). WEE response rates for same-day administration vs. non-same-day administration were independent of gender. A logistic regression model predicting response to WEE comparing group B to group A yielded an OR=2.14 (95% CL 1.22-3.73; p=.0077). We report immune interference occurring with same-day administration of two completely separate formalin inactivated viral vaccines in humans. These findings combined with the findings of others regarding immune interference would argue for a renewed emphasis on studying the immunological mechanisms of induction of inactivated viral vaccine protection.

Sex influences immune responses to viruses, and efficacy of prophylaxis and treatments for viral diseases

The intensity and prevalence of viral infections are typically higher in males, whereas disease outcome can be worse for females. Females mount higher innate and adaptive immune responses than males, which can result in faster clearance of viruses, but also contributes to increased development of immunopathology. In response to viral vaccines, females mount higher antibody responses and experience more adverse reactions than males. The efficacy of antiviral drugs at reducing viral load differs between the sexes, and the adverse reactions to antiviral drugs are typically greater in females than males. Several variables should be considered when evaluating male/female differences in responses to viral infection and treatment: these include hormones, genes, and gender-specific factors related to access to, and compliance with, treatment. Knowledge that the sexes differ in their responses to viruses and to treatments for viral diseases should influence the recommended course of action differently for males and females. Editor's suggested further reading in BioEssays X-chromosome-located microRNAs in immunity: Might they explain male/female differences Abstract.

Blood and body fluid exposure related knowledge, attitude and practices of hospital based health care providers in United arab emirates

OBJECTIVES

Knowledge, attitudes, and practices of healthcare providers related to occupational exposure to bloodborne pathogens were assessed in a tertiary-care hospital in Middle East.

METHODS

A cross-sectional study was undertaken using a self-administered questionnaire based on 3 paired (infectivity known vs. not known-suspected) case studies. Only 17 out of 230 respondents had an exposure in the 12 months prior to the survey and of these, only 2 had complied fully with the hospital's exposure reporting policy.

RESULTS

In the paired case studies, the theoretical responses of participating health professionals showed a greater preference for initiating self-directed treatment with antivirals or immunisation rather than complying with the hospital protocol, when the patient was known to be infected. The differences in practice when exposed to a patient with suspected blood pathogens compared to patient known to be infected was statistically significant (p < 0.001) in all 3 paired cases. Failure to test an infected patient's blood meant that an adequate risk assessment and appropriate secondary prevention could not be performed, and reflected the unwillingness to report the occupational exposure.

CONCLUSION

Therefore, the study demonstrated that healthcare providers opted to treat themselves when exposed to patient with infectious disease, rather than comply with the hospital reporting and assessment protocol.

A review of chronic hepatitis B epidemiology and management issues in selected countries in the Middle East

Experts from seven countries convened as a Specialist Panel for the Middle East to share information on practical issues relating to the epidemiology, diagnosis and management of chronic hepatitis B (CHB) infection. The Middle East is regarded as a region of high-to-intermediate epidemicity; however, infant vaccination programmes have successfully lowered the prevalence of hepatitis B infection in most countries to that of low-to-intermediate endemicity. Vaccine issues still to be addressed included improving coverage in some rural/poor communities, instituting hepatitis B vaccine at birth and providing vaccines for high-risk population groups. Hepatitis B infection in the Middle East primarily occurs as a result of perinatal infection, horizontal transmission between family members and transmission from injections. Blood transfusion services have broadly efficient screening programmes, but immunocompromised and haemodialysis patients are at risk. The cost of screening, monitoring and treating CHB influences practice in a number of Middle East countries, and there is a need for information on the most cost-effective options.

Anti-hepatitis B core antibody is not required for prevaccination screening in healthcare workers

Vaccination against hepatitis B virus (HBV) is recommended for health care workers (HCWs), but it is not clear whether HBV vaccination is required for HCWs who have isolated antibody to hepatitis B core antigen (anti-HBc), or whether prevaccination screening for anti-HBc is needed in HCWs. Among 1812 HCWs, subjects with isolated anti-HBc and those with no HBV markers (control) were screened. The anamnestic response (antibody to hepatitis B surface antigen over 50 mIU/mL after the first vaccine injection) was compared prospectively between the two groups. The prevalence of isolated anti-HBc was 2.3%. Their anamnestic response was lower than that of controls (27.5% vs. 46.9%, P=0.020). The subjects who had isolated anti-HBc were older and predominantly male, compared with the controls. Multivariate analysis revealed that age (odds ratio [OR], 0.67; confidence interval [CI], 0.51-0.90) and prior vaccination (OR, 3.36; CI, 2.04-5.54) were independent predictors of the anamnestic response, regardless of the anti-HBc status. Serum HBV DNA was not detected in any subject. Anti-HBs seroconversion was achieved in most of the anti-HBc-positive subjects after full vaccination, and the rate was comparable with controls (89.5% vs. 96.6%, P=0.067). Isolated anti-HBc-positive HCWs are rare and most of them respond to vaccination. Anti-HBc testing is not a prerequisite for vaccination. This serology suggests a loss of acquired anti-HBs rather than occult HBV infection. Their reduced immunity to vaccination may be related to old age.

The Xs and Y of immune responses to viral vaccines

The biological differences associated with the sex of an individual are a major source of variation, affecting immune responses to vaccination. Compelling clinical data illustrate that men and women differ in their innate, humoral, and cell-mediated responses to viral vaccines. Sex affects the frequency and severity of adverse effects of vaccination, including fever, pain, and inflammation. Pregnancy can also substantially alter immune responses to vaccines. Data from clinical trials and animal models of vaccine efficacy lay the groundwork for future studies aimed at identifying the biological mechanisms that underlie sex-specific responses to vaccines, including genetic and hormonal factors. An understanding and appreciation of the effect of sex and pregnancy on immune responses might change the strategies used by public health officials to start efficient vaccination programmes (optimising the timing and dose of the vaccine so that the maximum number of people are immunised), ensure sufficient levels of immune responses, minimise adverse effects, and allow for more efficient protection of populations that are high priority (eg, pregnant women and individuals with comorbid conditions).

Development of up-converting phosphor technology-based lateral-flow assay for rapidly quantitative detection of hepatitis B surface antibody

An up-converting phosphor technology-based lateral-flow (UPT-LF) assay system was developed for rapid and quantitative detection of hepatitis B surface antibody (HBsAb). To evaluate its performance, we compared it with the Abbott Axsym AUSAB (ABBOTT Diagnostics Division, Wiesbaden, Germany) assay and conventional ELISA (Wantai Biological Pharmacy Enterprise, Beijing, China) using 13 standard positive sera and 306 clinical sera. In both laboratory evaluation and clinical application, UPT-LF assay showed the best sensitivity (99.19%) and detection agreement (97.43% for the adjusted agreement) with true results. The concordance rate between UPT-LF and ELISA, as shown by correlative regression analysis, was the highest (R(2)=0.6389), whereas that between UPT-LF and AUSAB was the lowest (R(2)=0.5702). In conclusion, UPT-LF assay for quantitative detection of HBsAb is sensitive and rapid, promising this new assay a bright future.

Hepatitis B in Moroccan health care workers

AIM

To evaluate knowledge and perception of hepatitis B, including prevention, among Moroccan health care workers (HCWs) and to estimate seroprevalence of hepatitis B and vaccine coverage (VC).

METHODS

Four hundred and twenty HCWs were randomly selected and stratified by site: 120 in Rabat, 140 in Taza and 160 in Témara-Skhirat. The study included an anonymous questionnaire about knowledge of hepatitis B and its prevention and a serological survey. Oral statements and vaccine registers were used to analyse the VC of the HCWs. Serological testing and VC were analysed according to the occupational exposure.

RESULTS

Participation rates in the questionnaire and serological tests were 68% (285/420) and 66% (276/420), respectively. Fifteen (5%) HCWs had a history of hepatitis B. All HCWs considered that hepatitis B virus (HBV) infection may be acquired through blood exposure. Vaccination was acknowledged as a necessary means against HBV transmission by 276 (98%) HCWs. Forty-two per cent HCWs had no HBV serological markers. The prevalence of hepatitis B surface antigen was 1%. The mean prevalence of hepatitis B core antibody (anti-HBc) was 28% and was significantly higher (P < 0.05) among nursing auxiliaries (57%), nurses (30%), medical physicians (31%) and midwives (25%) than among laboratory technicians (13%). According to the vaccination registers (available in two sites), VC (> or =3 doses) was 55%. VC was 75% among midwives, 61% among nurses, 53% among nursing auxiliaries and 38% among medical staff. Of the fully vaccinated HCWs without anti-HBc, 51% had serological evidence of protection.

CONCLUSION

HBV vaccines should be more readily available for Moroccan HCWs by reinforcing current vaccination programmes.