Seroprotection after recombinant hepatitis B vaccination among newborn infants: a review

High Rates of Seroprotection to Hepatitis B After a Hepatitis B Challenge Dose in Previously Vaccinated Patients with Inflammatory Bowel Disease on Immunosuppressive Therapy

BACKGROUND

Healthy populations have high rates of sustained vaccine-induced seroprotection to hepatitis B virus, but previous studies in immunosuppressed patients with inflammatory bowel disease (IBD) have shown suboptimal seroprotection rates. A challenge dose of hepatitis B vaccine (HepB) is recommended in previously vaccinated individuals who are seronegative to elicit an anamnestic response and determine if they are seroprotected. The aim of our study was to determine sustained seroprotection rates to hepatitis B vaccine (HepB) in patients with IBD.

METHODS

This was a single-center prospective study of patients with IBD previously vaccinated with a three dose HepB series. Patients had a hepatitis B surface antibody (anti-HBs) drawn; if it was below 10 mIU/mL, they received a challenge dose of the HepB vaccine to assess for anamnestic response and sustained seroprotection. The primary outcome was to determine the rate of sustained seroprotection (anti-HBs ≥ 10).

RESULTS

A total of 168 patients met inclusion criteria, mean age 35.7 years ± 13.6 standard deviation (SD). Initially 120 (71.4%) had anti-HBs ≥ 10 mIU/mL, with median anti-HBs of 37 mIU/mL (interquartile range 0-234); 48 (28.6%) needed a challenge dose, of which 34 responded with anti-HBs ≥ 10 mIU/mL. In total, 154 (91.7%) demonstrated sustained seroprotection to HepB. Those not seroprotected were more likely to have been vaccinated on immunosuppressive therapy or after their diagnosis of IBD.

CONCLUSIONS

Most vaccinated patients with IBD maintain sustained seroprotection to HepB despite prolonged exposure to immunosuppression. This contradicts prior studies and shows that immunosuppression does not lead to loss of seroprotection.

Seroconversion among children with HBsAg-positive mothers in Indonesia and factors affecting the anti-HBs titers

Background and aim

Around 2% of newborns are at risk of hepatitis B virus (HBV) infection from their mothers. To prevent this, infants born to HBsAg-positive mothers are given hepatitis B immune globulin (HBIG) and hepatitis B (HB) vaccine as immunoprophylaxis. This study aims to investigate the efficacy of immunoprophylaxis in infants born to HBsAg-positive mothers and the contributing factors.

Methods

The study was conducted on a group of 87 children, ranging from nine months to under 36 months, born to HBsAg-positive mothers and received immunoprophylaxis within 24 h after birth followed by a national immunization schedule at the Community Health Center (CHC) in three administrative cities of DKI Jakarta. We measured the levels of HBsAg and anti-HBs, and utilized ordinal logistic regression models to identify factors that influence the anti-HBs titers after vaccination.

Results

Out of 87 children, only one child had positive HBsAg results. The data showed that 88.5% of the children had seroprotection with anti-HBs levels ≥10 mIU/mL. Additionally, 48.3% of the children had a high protective response with anti-HBs levels ≥100 mIU/mL, while 11.5% had a non-protective response. Children under one year of age, with a family history of HBV carriers, and who received five doses of the HB vaccine exhibited higher levels of anti-HBs titer category with adjusted OR 3.9 (95%CI: 1.3-11.6), 5.3 (95%CI: 1.1-27.4), and 8.3 (95%CI: 2-34.8), respectively.

Conclusion

The administration of HBIG and HB vaccine successfully prevented vertical transmission, resulting in a high seroprotection rate.

Hepatitis B Vaccine: Four Decades on

Hepatitis B virus is a substantial contributor to cirrhosis and hepatocellular carcinoma (HCC) globally. Vaccination is the most effective method for prevention of hepatitis B and its associated morbidity and mortality, and the only method to prevent infection with hepatitis D virus. The hepatitis B vaccine has been used worldwide for more than four decades; it is available in a single- or triple-antigen form and in combination with vaccines against other infections. Introduction of the vaccine and administration at birth led to sustained decline in mother-to-child transmission, chronic hepatitis B, and HCC, however, global birth dose coverage remains suboptimal. In this review we will discuss different hepatitis B vaccine formulations and schedules, vaccination guidelines, durability of the response, and vaccine escape mutants, as well as the clinical and economic benefits of vaccination.

Immune response to hepatitis B vaccine among children under 5 years in Africa: a meta-analysis

BACKGROUND

Hepatitis B virus (HBV) infection in Africa is mostly acquired before the age of 5 years through vertical or horizontal routes. While all the countries in the World Health Organization African region have introduced HBV vaccination into their national immunization programs, the rate of protective immune response to HBV vaccine among children in Africa has not been systematically synthesized. In this study, we estimated the HBV vaccine seroprotection rate (defined as anti-HBs titer ≥ 10 IU/L) and the associated factors among under-five children who completed a primary series of HBV vaccination in Africa.

METHODS

We systematically searched PubMed, Web Science, and Scopus databases from inception to May 2022 for potentially eligible studies. The pooled seroprotection rate was estimated using a random-effects model with Freeman-Tukey double arcsine transformation and the associated factors were examined using odds ratio estimated by the DerSimonian and Laird method.

RESULTS

From the 1063 records identified, 29 studies with a total sample size of 9167 under-five children were included in the meta-analysis. The pooled seroprotection rate was 89.23% (95% CI   85.68-92.33%, I2 = 95.96%, p < 0.001). In the subgroup analyses, there was a significant difference in the rate by the assay method, vaccine dose, and vaccine combination. HIV-positive children had lower odds of achieving seroprotection when compared with HIV-negative children (OR = 0.22, 95%CI   0.12-0.40).

CONCLUSIONS

The majority of under-five children in Africa achieved seroprotection after completing three or four doses of HBV vaccine. However, the rate was lower among children living with HIV. This calls for interventions to timely identify and address nonresponse to HBV vaccine, particularly among immunosuppressed children.

Impact of hepatitis B birth dose on immune response in Pakistani children: an open-label, non-inferiority randomized controlled trial, implications for achieving SDG target

BACKGROUND

Despite presence of hyperendemic areas, the national immunisation schedule in Pakistan does not include a hepatitis B birth dose, placing newborns at an additional risk of acquiring hepatitis B. This study aimed to assess the impact of adding hepatitis B birth dose in existing national vaccination schedule.

METHODS

An open label, randomised controlled non-inferiority trial enrolled 296 healthy near-term mothers to intervention and control groups. Newborns in the intervention group received a hepatitis B birth dose along with routine immunisation vaccines, while control group newborns received vaccinations under the national schedule. Seroprotection was measured and compared at birth and 8 weeks after administering the third dose of pentavalent vaccine. The risk ratio of seroprotection was computed and compared with the delta value set at 5%.

RESULTS

The study found that 95.8% of infants in the intervention group achieved seroprotection, which was significantly higher than the control group's 58.7%. The difference in risk ratio of seroprotection was 1.62 (CI95: 1.37-1.93), with the upper limit of the CI below the delta margin, confirming non-inferiority. The time interval between birth and the first hepatitis B immunisation shot was a predictor of seroprotection, with an odds ratio of 1.79 (CI95: 1.01-2.9).

CONCLUSION

Our study indicates that adding a hepatitis B birth dose to the immunisation schedule in Pakistan is non-inferior to the existing one. This can also contribute towards Pakistan's achievement of the SDG target of reducing hepatitis B surface antigen seroprevalence in children under 5 years of age.

TRIAL REGISTRATION NUMBER

NCT04870021.

Hepatitis B Virus vaccination post serological testing and antibody levels of vaccinated health care workers in Accra, Ghana

Introduction

Hepatitis B Virus (HBV) infection is an important occupational hazard to Health Care Workers (HCWs) all over the world. International health organizations have strongly recommended the use of the HBV vaccine, especially among individuals at risk of HBV infection. A laboratory test aimed at measuring Anti-HBs concentration (titer) 1-2 months following a 3-dose vaccination schedule is the most reliable approach for diagnosing seroprotection against HBV. This study sought to assess post-vaccination serological testing, seroprotection against HBV, and associated factors among vaccinated HCWs in Ghana.

Methods

A hospital-based analytical cross-sectional study involving 207 HCWs. Pretested questionnaires were used to collect data. 5mls of venous blood were collected from consenting HCWs under strict aseptic conditions and quantitatively analyzed for Anti-HBs using ELISA procedures. SPSS Version 23 was used to analyze data with the level of significance set at 0.05.

Results

Median age; 33, IQR of 29-39. The post-vaccination serological testing rate was 21.3 %. HCWs with high-risk perception and working at the regional hospital had lower odds of adherence to post-vaccination serological testing (aOR = 0.2; 95 % CI = 0.1-0.7) and (aOR = 0.1; 95 % CI = 0.1-0.6) p < 0.05. The seroprotection rate was 91.3 % (95 % CI = 87 %-95 %). Minority, 18 (8.7 %) of the 207 vaccinated HCWs had antibody titers below 10mIU/mL and were not seroprotected against HBV. Geometric Mean Titers (GMTs) were higher in those who received three doses, took a booster, and were less than 25 kg/m².

Conclusion

The post-vaccination serological testing practice was sub-optimal. The seroprotection rate was higher with higher GMTs in those who adhered to the 3-dose vaccination regimen, took a booster dose, and had BMI < 25 kg/m². It may be inferred that those with Anti-HBs below 10 IU/ml had their antibodies diminishing or waning off with time or they are true vaccine non-responders. This observation calls for strict adherence to post-vaccination serological testing, especially for HCWs who are at high risk of percutaneous and mucocutaneous exposures that could result in HBV infection.

Eliminating viral hepatitis in children after liver transplants: How to reach the goal by 2030

Viral hepatitis infections are a great burden in children who have received liver transplant. Hepatotropic viruses can cause liver inflammation that can develop into liver graft fibrosis and cirrhosis over the long term. Immunological reactions due to viral hepatitis infections are associated with or can mimic graft rejection, rendering the condition difficult to manage. Prevention strategies using vaccinations are agreeable to patients, safe, cost-effective and practical. Hence, strategies to eliminate viral hepatitis A and B focus mainly on immunization programmes for children who have received a liver transplant. Although a vaccine has been developed to prevent hepatitis C and E viruses, its use is not licensed worldwide. Consequently, eliminating hepatitis C and E viruses mainly involves early detection in children with suspected cases and effective treatment with antiviral therapy. Good hygiene and sanitation are also important to prevent hepatitis A and E infections. Donor blood products and liver grafts should be screened for hepatitis B, C and E in children who are undergoing liver transplantation. Future research on early detection of viral hepatitis infections should include molecular techniques for detecting hepatitis B and E. Moreover, novel antiviral drugs for eradicating viral hepatitis that are highly effective and safe are needed for children who have undergone liver transplantation.

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.

Machine Learning-Based Single Cell and Integrative Analysis Reveals That Baseline mDC Predisposition Correlates With Hepatitis B Vaccine Antibody Response

Vaccination to prevent infectious disease is one of the most successful public health interventions ever developed. And yet, variability in individual vaccine effectiveness suggests that a better mechanistic understanding of vaccine-induced immune responses could improve vaccine design and efficacy. We have previously shown that protective antibody levels could be elicited in a subset of recipients with only a single dose of the hepatitis B virus (HBV) vaccine and that a wide range of antibody levels were elicited after three doses. The immune mechanisms responsible for this vaccine response variability is unclear. Using single cell RNA sequencing of sorted innate immune cell subsets, we identified two distinct myeloid dendritic cell subsets (NDRG1-expressing mDC2 and CDKN1C-expressing mDC4), the ratio of which at baseline (pre-vaccination) correlated with the immune response to a single dose of HBV vaccine. Our results suggest that the participants in our vaccine study were in one of two different dendritic cell dispositional states at baseline – an NDRG2-mDC2 state in which the vaccine elicited an antibody response after a single immunization or a CDKN1C-mDC4 state in which the vaccine required two or three doses for induction of antibody responses. To explore this correlation further, genes expressed in these mDC subsets were used for feature selection prior to the construction of predictive models using supervised canonical correlation machine learning. The resulting models showed an improved correlation with serum antibody titers in response to full vaccination. Taken together, these results suggest that the propensity of circulating dendritic cells toward either activation or suppression, their “dispositional endotype” at pre-vaccination baseline, could dictate response to vaccination.

The optimal interval for post-vaccination serological test in infants born to mothers with positive hepatitis B surface antigen

Postvaccination serologic testing (PVST) is utilized to monitor the success or failure of vaccination against hepatitis B virus (HBV) infection in infants of hepatitis B surface antigen (HBsAg) positive mothers. This secondary analysis of 1255 infants of HBsAg-positive mothers at 7-14 months age included in two prospective studies aimed to determine the optimal interval for PVST after three hepatitis B vaccine doses. HBsAg and anti-HBs were quantitatively tested with microparticle enzyme immunoassay. The average PVST interval was 3.8 ± 2.2 months. Overall, 1.7% (21/1255) infants had anti-HBs <10 mIU/mL. The non-response rates were 1.6%, 1.1%, 0.9%, 0.7%, 1.1%, 0.7%, and 5.7% when PVST was performed at an interval of 1, 2, 3, 4, 5, 6, and 7-8 months after the third vaccine dose, respectively. Compared with 1 month of PVST interval, the non-response rate in infants who underwent PVST 7-8 months was significantly higher (χ² = 4.616, P = .032). Anti-HBs titers were significantly declined in infants with medium responses when PVST was performed with longer intervals (χ² = 27.592, P < .001), actually declined from interval of 6, and 7-8 months (Z = -3.177, P = .001 and Z = -3.715, P < .001), respectively. These results indicate that PVST may be performed at the age of 7-12 months for infants vaccinated on 0, 1, and 6-month schedule. To identify non-responders as early as possible, we suggest that PVST is performed at 7 months age or 1 month after the final vaccine dose.

ESHRE guideline: medically assisted reproduction in patients with a viral infection/disease

STUDY QUESTION

What is the recommended management for medically assisted reproduction (MAR) in patients with a viral infection or disease, based on the best available evidence in the literature?

SUMMARY ANSWER

The ESHRE guideline on MAR in patients with a viral infection/disease makes 78 recommendations on prevention of horizontal and vertical transmission before, during and after MAR, and the impact on its outcomes, and these also include recommendations regarding laboratory safety on the processing and storage of gametes and embryos testing positive for viral infections.

WHAT IS KNOWN ALREADY

The development of new and improved anti-viral medications has resulted in improved life expectancy and quality of life for patients with viral infections/diseases. Patients of reproductive age are increasingly exploring their options for family creation.

STUDY DESIGN SIZE DURATION

The guideline was developed according to the structured methodology for the development of ESHRE guidelines. After the formulation of nine key questions for six viruses (hepatitis B virus, hepatitis C virus, human immunodeficiency virus, human papilloma virus, human T-lymphotropic virus I/II and Zika virus) by a group of experts, literature searches and assessments were performed. Papers published up to 2 November 2020 and written in English were included in the review. Evidence was analyzed by female, male or couple testing positive for the virus.

PARTICIPANTS/MATERIALS SETTING METHODS

Based on the collected evidence, recommendations were formulated and discussed until consensus was reached within the guideline group. There were 61 key questions to be answered by the guideline development group (GDG), of which 12 were answered as narrative questions and 49 as PICO (Patient, Intervention, Comparison, Outcome) questions. A stakeholder review was organized after the finalization of the draft. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

This guideline aims to help providers meet a growing demand for guidance on the management of patients with a viral infection/disease presenting in the fertility clinic.The guideline makes 78 recommendations on prevention of viral transmission before and during MAR, and interventions to reduce/avoid vertical transmission to the newborn. Preferred MAR treatments and interventions are described together with the effect of viral infections on outcomes. The GDG formulated 44 evidence-based recommendations-of which 37 were formulated as strong recommendations and 7 as weak-33 good practice points (GPP) and one research only recommendation. Of the evidence-based recommendations, none were supported by high-quality evidence, two by moderate-quality evidence, 15 by low-quality evidence and 27 by very low-quality evidence. To support future research in the field of MAR in patients with a viral infection/disease, a list of research recommendations is provided.

LIMITATIONS REASONS FOR CAUTION

Most interventions included are not well-studied in patients with a viral infection/disease. For a large proportion of interventions, evidence was very limited and of very low quality. More evidence is required for these interventions, especially in the field of human papilloma virus (HPV). Such future studies may require the current recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in MAR for patients with a viral infection/disease, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in the field.

STUDY FUNDING/COMPETING INTERESTS

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive any financial incentives, all work was provided voluntarily. A.D. reports research fees from Ferring and Merck, consulting fees from Ferring, outside the submitted work. C.P. reports speakers fees from Merck and MSD outside the submitted work. K.T. reports speakers fees from Cooper Surgical and Ferring and consultancy fees as member of the advisory board BioTeam of Ferring, outside the submitted work. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at  www.eshre.eu/guidelines.).

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Efficacy of hepatitis B vaccination in children with rheumatic diseases

BACKGROUND

Vaccination to prevent hepatitis B (HB) virus infection is important for children undergoing immunosuppressive treatment. Information on the efficacy of HB vaccination in children with rheumatic diseases undergoing immunosuppressive therapy is scarce.

METHODS

Children with rheumatic diseases administered HB vaccine during immunosuppressive treatment between May 2013 and September 2016 were enrolled. Patients were vaccinated three times (primary series). Those who remained seronegative after the primary series received a secondary series of vaccinations. Patient baseline characteristics and treatment details from the medical records were retrospectively investigated. The proportion of patients that was seropositive for HB virus antibody after primary-and secondary series of vaccinations was calculated. Associations between immunosuppressants and serostatus were evaluated.

RESULTS

Fifteen of 26 patients (58%) produced anti-hepatitis B surface antibody (anti-HBs) after the primary vaccinations. Eight of 10 patients (80%) taking methotrexate and 3 of 11 (27%) taking mycophenolate mofetil (MMF) were seropositive. Multivariate analysis adjusted for dosage of prednisolone per body weight. Multivariate analysis showed MMF was a factor impeding seroconversion (odds ratio 0.093, 95% confidence interval 0.014-0.615). In six of seven patients (86%) who received a secondary series of vaccinations, anti-HBs were produced.

CONCLUSIONS

MMF may impede seroconversion after a primary series of HB vaccinations, thus requiring secondary series of vaccinations in pediatric patients with a rheumatic disease undergoing immunosuppressive therapy.

Chronic hepatitis B in pregnant women: Current trends and approaches

Chronic hepatitis B (CHB) is a significant public health problem worldwide. The aim of the present review is to summarize the actual trends in the management of CHB in pregnant women. The prevalence of hepatitis B virus (HBV) infection in pregnant women is usually comparable to that in the general population in the corresponding geographic area. All women have to be screened for hepatitis B surface antigen (HBsAg) during pregnancy. Additional examinations of pregnant women with CHB may include maternal hepatitis B e antigen, HBV viral load, alanine aminotransferase level, and HBsAg level. The management of pregnancy depends on the phase of the HBV infection, which has to be determined before pregnancy. In women of childbearing age with CHB, antiviral therapy can pursue two main goals: Treatment of active CHB, and vertical transmission prevention. During pregnancy, tenofovir is the drug of choice in both cases. A combination of hepatitis B immunoglobulin and vaccine against hepatitis B should be administered within the first 12 h to all infants born to mothers with CHB. In such cases, there are no contraindications to breastfeeding.

Improving timeliness of hepatitis B vaccine administration in an urban safety net level III NICU

OBJECTIVE

To avoid preventable consequences of perinatal hepatitis B infection, all infants should be given hepatitis B vaccine (HBV) within 24 hours of birth if birth weight is ≥2 kg and at 30 days of life or at discharge if <2 kg, to provide highest seroprotection rates while ensuring universal vaccination prior to discharge. We aimed to achieve timely HBV administration in >80% of eligible infants in both birthweight groups and decrease infants discharged home without receiving HBV to <1% over an 18-month period and sustain results for an additional 15 months.

METHODS

Data were collected from June 2016 to May 2020 in a level III neonatal intensive care unit. A multidisciplinary team identified barriers and interventions through Plan-Do-Study-Act cycles from September 2017 to February 2019: using pharmacists as champions, overcoming legal barriers, staff education and best practice alerts (BPAs) embedded in electronic health records. Statistical process control (SPC) p charts were used to evaluate the primary outcome measure, monthly percentage of infants receiving timely HBV administration stratified by birthweight categories (≥2 and <2 kg). For infants receiving HBV outside the time frame, absolute difference of timeliness was calculated.

RESULTS

Mean timely HBV administration improved from 45% to 95% (≥2 kg) and from 45% to 85% (<2 kg) with special cause variation in SPC charts. Infants discharged without receiving HBV decreased from 4.6% to 0.22%. Of those given HBV outside the recommended time frame, median absolute time between recommended and actual administration time decreased significantly: from 3.5 days (IQR 1.6, 8.6) to 0.3 day (IQR 0.1, 0.8) (p<0.001) in ≥2 kg group and from 6 days (IQR 1, 15) to 1 day (IQR 1, 6.5) (p=0.009) in <2 kg group.

CONCLUSIONS

Using a multidisciplinary approach, we significantly improved and sustained timely HBV administration and nearly eliminated infants discharged home without receiving HBV. Pharmacists as champions and BPAs were critical to our success.

Brazilian Protocol for Sexually Transmitted Infections 2020: viral hepatitis

This article discusses viral hepatitis, a theme addressed by the Clinical Protocol and Therapeutic Guidelines to Comprehensive Care for People with Sexually Transmitted Infections and, more precisely, by the Clinical Protocols and Therapeutic Guidelines for Hepatitis B and Hepatitis C and Coinfections, published by the Brazilian Ministry of Health. Besides the broad spectrum of health impairment, hepatitis A, B, and C viruses also present different transmission forms, whether parenteral, sexual, vertical, or fecal-oral. Among the strategies suggested for the control of viral hepatitis, in addition to behavioral measures, are expanded diagnosis, early vaccination against hepatitis A and hepatitis B viruses, and access to available therapeutic resources. Considering vertical transmission of the hepatitis B and hepatitis C viruses, screening for pregnant women with chronic hepatitis B and C is an essential perinatal health strategy, indicating with precision those who can benefit from the prophylactic interventions. Viral hepatitis A, B, and C are responsible for more than 1.34 million deaths worldwide every year, from which 66% are the result of hepatitis B, 30% of hepatitis C, and 4% of hepatitis A.

Vaccine-induced protection against hepatitis B in pediatric solid organ transplant patients

BACKGROUND

Vaccination against hepatitis B virus (HBV) has led to a worldwide reduction in disease burden and mortality. Vaccine immunogenicity data in transplanted children are limited, and vaccine-induced protection may be reduced. We evaluated HBV vaccination coverage, seroprotection rates, and factors influencing vaccine immunity among pediatric solid organ transplant (SOT) patients.

METHODS

We retrospectively identified patients ≤21 years of age evaluated for SOT and/or transplanted at our center between January 1, 2015, and December 31, 2018. A detailed chart review was conducted using a standard questionnaire to gather information on demographic, clinical, and laboratory features of patients' HBV vaccination, and hepatitis B surface antibody (HBsAb) titers.

RESULTS

A total of 381 patients undergoing evaluation and/or transplantation were included: 139 (36.5%) liver, 138 (36.2%) kidney, and 104 (27.3%) heart. Overall, HBsAb at evaluation was reactive in 216 (56.7%), indeterminate in 17 (4.5%), non-reactive in 138 (36.2%), and not available in 10 (2.6%). Of those that completed a primary HBV vaccine series (n = 304), HBsAb was reactive in 164 (53.9%), indeterminate in 13 (4.3%), non-reactive in 119 (39.1%), and not available in 8 (2.6%). For those up to date for age on HBV vaccinations with non-reactive/indeterminate titers at evaluation, revaccination and a follow-up HBsAb were available in 45 patients of which 33 (73.3%) seroconverted to a reactive HBsAb titer.

CONCLUSION

Vaccine-induced protection against HBV infection among high-risk pediatric SOT recipients can be improved by serology-based intervention. Though the absence of HBsAb does not always indicate loss of protection, boosting or completing primary series is recommended.

[Brazilian Protocol for Sexually Transmitted Infections 2020: viral hepatitis]

This article discusses viral hepatitis, a theme addressed by the Clinical Protocol and Therapeutic Guidelines to Comprehensive Care for People with Sexually Transmitted Infections and, more precisely, by the Clinical Protocols and Therapeutic Guidelines for Hepatitis B and Hepatitis C and Coinfections, published by the Brazilian Ministry of Health. Besides the broad spectrum of health impairment, hepatitis A, B and C viruses also present different forms of transmission, whether parenteral, sexual, vertical or oral. Among the strategies suggested for the control of viral hepatitis, in addition to behavioral measures, are expanded diagnosis, early vaccination against hepatitis A and hepatitis B viruses, and access to available therapeutic resources. Considering vertical transmission of the hepatitis B and hepatitis C viruses, screening for pregnant women with chronic hepatitis B and C is an important perinatal health strategy, indicating with precision those who can benefit from the prophylactic interventions.

National Perinatal Hepatitis B Prevention Program: 2009-2017

OBJECTIVES

To assess trends and programmatic outcomes among infants born to hepatitis B surface antigen (HBsAg)-positive women from 2009 to 2017 and case-managed by the Centers for Disease Control and Prevention's national Perinatal Hepatitis B Prevention Program (PHBPP).

METHODS

We analyzed 2009-2017 annual programmatic reports submitted by 56 US jurisdictions funded through the Centers for Disease Control and Prevention's PHBPP to assess characteristics of maternal-infant pairs and achievement of objectives of infant hepatitis B postexposure prophylaxis, vaccine series completion, and postvaccination serologic testing (PVST). We compared the number of maternal-infant pairs identified by the program with the number estimated born to HBsAg-positive women from 2009 to 2014 and 2015 to 2017 by using a race and/or ethnicity and maternal country of birth methodology, respectively.

RESULTS

The PHBPP identified 103 825 infants born to HBsAg-positive women from 2009 to 2017, with a range of 10 956 to 12 103 infants annually. Births estimated annually to HBsAg-positive women increased nonsignificantly from 24 804 in 2009 to 26 444 in 2014 (P = .0540) and 20 678 in 2015 to 20 832 in 2017 (P = .8509). The proportion of infants identified annually increased overall from 48.1% to 52.6% (P = .0983). The proportion of case-managed infants receiving postexposure prophylaxis, at least 3 vaccine doses, and PVST increased overall from 94.7% to 97.0% (P = .0952), 83.1% to 84.7% (P = .5377) and 58.8% to 66.8% (P = .0002), respectively.

CONCLUSIONS

The PHBPP has achieved success in managing infants born to HBsAg-positive women and ensuring their immunity to hepatitis B. Nonetheless, strategies are needed to close gaps between the number of infants estimated and identified, increase vaccine series completion, and increase ordering of recommended PVST for all case-managed infants.

Vaccination of Term and Preterm Infants

Newborns, especially those born preterm, are at high risk for infection. Preterm birth rates appear to be increasing in most countries, with ∼15 million infants born preterm globally each year, corresponding to ∼11% of all deliveries. Importantly, the vulnerability of preterm infants to infection continues beyond the perinatal period, following them throughout childhood and adolescence, highlighting the long-lasting effects of infection on overall health and well-being. Other than access to clean drinking water and proper sewage systems, immunization is the most effective biomedical intervention to reduce early life infection. Nevertheless, a significant proportion of infants discharged on or after 2 months of age from the NICU remains unimmunized or underimmunized at that time. Despite being safe and effective, protective responses to immunization in early life are different from those in older individuals, in part because of the distinct immune system of newborns and young infants. The paradigms of the Bacille Calmette-Guérin, hepatitis B, and polio vaccines, the only immunizations currently routinely administered in the neonatal period, provide evidence that it is feasible to successfully administer vaccines via different routes of delivery; thus, production of sufficient vaccine-induced immunity leads to disease prevention in the newborn. Strategies such as maternal immunization, adjuvantation systems, leveraging trained immunity, and counseling caregivers can be used to enhance vaccine-induced specific and heterologous protection from infection and boost adherence to the recommended immunization schedule.

Multi-Omic Data Integration Allows Baseline Immune Signatures to Predict Hepatitis B Vaccine Response in a Small Cohort

Background

Vaccination remains one of the most effective means of reducing the burden of infectious diseases globally. Improving our understanding of the molecular basis for effective vaccine response is of paramount importance if we are to ensure the success of future vaccine development efforts.

Methods

We applied cutting edge multi-omics approaches to extensively characterize temporal molecular responses following vaccination with hepatitis B virus (HBV) vaccine. Data were integrated across cellular, epigenomic, transcriptomic, proteomic, and fecal microbiome profiles, and correlated to final HBV antibody titres.

Results

Using both an unsupervised molecular-interaction network integration method (NetworkAnalyst) and a data-driven integration approach (DIABLO), we uncovered baseline molecular patterns and pathways associated with more effective vaccine responses to HBV. Biological associations were unravelled, with signalling pathways such as JAK-STAT and interleukin signalling, Toll-like receptor cascades, interferon signalling, and Th17 cell differentiation emerging as important pre-vaccination modulators of response.

Conclusion

This study provides further evidence that baseline cellular and molecular characteristics of an individual's immune system influence vaccine responses, and highlights the utility of integrating information across many parallel molecular datasets.

Revaccination management of a large cohort of pediatric patients following a potential lapse in cold storage

INTRODUCTION

In a pediatric clinic in California (US), 3823 patients were vaccinated with potentially-compromised vaccines following lapses in cold storage chain management between February 2014 and April 2015. A revaccination program was initiated in May 2015. Families were contacted by mail and encouraged to discuss follow-up options with their care team, namely: revaccination, serological testing and/or revaccination, or no further action. This study aimed: to understand which families were more likely to respond to the outreach, and to engage in any testing and/or revaccination; to determine whether or not vaccination with these potentially-compromised vaccines elicited sufficient immune response in pediatric patients; and to estimate the program cost.

METHODS

Patients who had received potentially-compromised vaccines were identified, and relevant data were extracted from their electronic health records. Logistic regression analyses were performed to identify factors associated with response to outreach, serological testing and/or revaccination.

RESULTS

3823 patients between 0 and 21 years received an average of 3.1 potentially-compromised vaccines. 2547 revaccinations were performed (1515 patients) and 544 patients had serological testing results. Non-immune titer levels were only reported for 3-4% and 8% of the tested patients who had received potentially-compromised tetanus and hepatitis B vaccines, respectively, and only for children two years old and younger. Three years after the revaccination program started, 77% of all cases were considered resolved and 62.5% of patients (1970/3152) who were administered potentially-compromised vaccines were either revaccinated or had seroprotective titers. Response to outreach and decision to choose serological testing and/or revaccinate were affected by patient age, race/ethnicity and zip code median income (p < 0.05).

CONCLUSION

We observed race/ethnicity, patient age and income differences in response to the outreach and decision-making. For patients vaccinated with potentially-compromised vaccines, serological testing should be considered prior to revaccination. Revaccination may not be the most appropriate course of action for all patients.

Immune response to hepatitis B vaccination in pediatric patients with inflammatory bowel disease

AIM OF THE STUDY

To evaluate the immune response rate in children with inflammatory bowel disease (IBD) who received the full hepatitis B vaccination course in infancy. We also evaluated rates of response to booster doses.

MATERIAL AND METHODS

Participants were 1- to 18-year-old children with IBD, who received 3 doses of the hepatitis B vaccine in infancy. The study subjects were on no immunosuppressive therapy, on immunomodulators, on biological therapy, or received combo therapy. Anti-hepatitis B surface antibody (anti-HBs) level ≥ 10 mIU/ml was considered to be seroprotective. Patients with anti-HBs level < 10 mIU/ml received 1 or 3 doses of hepatitis B vaccine, and their post-vaccination anti-HBs levels were evaluated.

RESULTS

In total, we included 157 subjects, with a median age of 14.5 years. Anti-HBs levels ≥ 10 mIU/ml were found in 84/157 (53.5%) patients and were not associated with age (p = 0.3), sex (p = 0.7), or IBD type (p = 0.9). There was no significant difference in the rate of seroconversion between IBD patients treated with no immunosuppressive drugs, immunomodulators, biologicals, and combo therapy (30.4% vs. 39.3% vs. 2.7% vs. 7.1%, respectively, p = 0.3). After the first and third dose of booster vaccine, anti-HBs levels ≥ 10 mIU/ml were as follows: 92% and 100%, respectively.

CONCLUSIONS

The immune response in children with IBD, who received the full series of hepatitis B vaccinations in infancy was inadequate and did not depend on the type of therapy. The booster dose(s) of vaccine could help to protect this group of patients from hepatitis B virus.

Quasispecies characteristic in "a" determinant region is a potential predictor for the risk of immunoprophylaxis failure of mother-to-child-transmission of sub-genotype C2 hepatitis B virus: a prospective nested case-control study

OBJECTIVE

This study was performed to explore the correlation between the characteristics of hepatitis B virus (HBV) quasispecies in HBV-infected pregnant women and the risk of immunoprophylaxis failure for their infants.

DESIGN

In this prospective nested case-control study, the characteristics of HBV quasispecies in mothers whose infants were immunoprophylaxis success (control group) and those whose infants were immunoprophylaxis failure (case group) were analysed by the clone-based sequencing of full-length HBV genome and next-generation sequencing (NGS) of "a" determinant region, and were compared between the two groups.

RESULTS

The quasispecies characteristics including mutant frequency, Shannon entropy and mean genetic distance at amino acid level of "a" determinant region were significantly lower in case group than that in control group, using the full-length HBV genome clone-based sequencing assay. These results were confirmed by NGS assay. Notably, we discovered that the differences were also significant at nucleotide level by NGS assay. Furthermore, the risk of immunoprophylaxis failure could be predicted by analysing the three HBV quasispecies characteristics either at nucleotide level or at amino acid level of "a" determinant region, and the corresponding predictive values were tentatively set up.

CONCLUSIONS

HBV quasispecies with a more complex mutant spectrum in "a" determinant region might be more vulnerable to extinct through mother-to-child-transmission (MTCT). More importantly, analysing HBV quasispecies characteristics in pregnant women with high HBV DNA load might be helpful to predict the high-risk population of immunoprophylaxis failure, and consequently provide accurate intervention against MTCT of HBV.

Improving Vaccine-Induced Immunity: Can Baseline Predict Outcome?

Immune signatures measured at baseline and immediately prior to vaccination may predict the immune response to vaccination. Such pre-vaccine assessment might allow not only population-based, but also more personalized vaccination strategies (‘precision vaccination’). If baseline immune signatures are predictive, the underlying mechanism they reflect may also determine vaccination outcome. Thus, baseline signatures might contribute to identifying interventional targets to be modulated prior to vaccination in order to improve vaccination responses. This concept has the potential to transform vaccination strategies and usher in a new approach to improve global health.

Extensive baseline variability in immune responses (e.g., antibody titers) among individuals in given populations is increasingly being appreciated as a major contributor to vaccine response heterogeneity.

The concept of ‘baseline may predict outcome’ has recently been reported for human influenza virus, yellow fever virus, and hepatitis B virus, as well as malaria vaccination. This concept might also apply to other vaccines.

The ability to predict who might respond to immunization (and to what extent) might offer avenues for optimization of current vaccination strategies.

We posit that this simple concept might be useful and significant for vaccine design: if ‘baseline determines outcome, then altering baseline prior to vaccination could alter outcome’.

This approach could potentially lead to tailored (precision) vaccines ensuring that the majority, or all individuals vaccinated, respond by eliciting a protective immune response (i.e., devoid of non-responder individuals). Presumably, this approach might also allow the administration of fewer vaccine doses, potentially arriving at one vaccine dose only.

Clinical Protocol for a Longitudinal Cohort Study Employing Systems Biology to Identify Markers of Vaccine Immunogenicity in Newborn Infants in The Gambia and Papua New Guinea

Background: Infection contributes to significant morbidity and mortality particularly in the very young and in low- and middle-income countries. While vaccines are a highly cost-effective tool against infectious disease little is known regarding the cellular and molecular pathways by which vaccines induce protection at an early age. Immunity is distinct in early life and greater precision is required in our understanding of mechanisms of early life protection to inform development of new pediatric vaccines. Methods and Analysis: We will apply transcriptomic, proteomic, metabolomic, multiplex cytokine/chemokine, adenosine deaminase, and flow cytometry immune cell phenotyping to delineate early cellular and molecular signatures that correspond to vaccine immunogenicity. This approach will be applied to a neonatal cohort in The Gambia (N ~ 720) receiving at birth: (1) Hepatitis B (HepB) vaccine alone, (2) Bacille Calmette Guerin (BCG) vaccine alone, or (3) HepB and BCG vaccines, (4) HepB and BCG vaccines delayed till day 10 at the latest. Each study participant will have a baseline peripheral blood sample drawn at DOL0 and a second blood sample at DOL1,-3, or-7 as well as late timepoints to assess HepB vaccine immunogenicity. Blood will be fractionated via a "small sample big data" standard operating procedure that enables multiple downstream systems biology assays. We will apply both univariate and multivariate frameworks and multi-OMIC data integration to identify features associated with anti-Hepatitis B (anti-HB) titer, an established correlate of protection. Cord blood sample collection from a subset of participants will enable human in vitro modeling to test mechanistic hypotheses identified in silico regarding vaccine action. Maternal anti-HB titer and the infant microbiome will also be correlated with our findings which will be validated in a smaller cohort in Papua New Guinea (N ~ 80). Ethics and Dissemination: The study has been approved by The Gambia Government/MRCG Joint Ethics Committee and The Boston Children's Hospital Institutional Review Board. Ethics review is ongoing with the Papua New Guinea Medical Research Advisory Committee. All de-identified data will be uploaded to public repositories following submission of study output for publication. Feedback meetings will be organized to disseminate output to the study communities. Clinical Trial Registration: Clinicaltrials.gov Registration Number: NCT03246230.

Long-term follow-up of a vaccination program for infants born to HBsAg-positive mothers in Stockholm County, Sweden

We investigated the long-term antibody response to hepatitis B virus (HBV) vaccination in babies born to chronically infected mothers. They received one dose of monovalent HBV vaccination at birth and one month of age, followed by 3 doses of hexavalent vaccine including an HBV component at ages 3, 5, and 12 months, respectively, with a very high percentage of protective anti-HBs levels at 13 months. At the age of 8-12 years, 56 out of 68 children (82%) had protective levels of anti-HBs, two had signs of anti-HBc seroconversion without any history of clinical disease and none had ongoing infection. A small subgroup was retested after one booster dose, in all resulting in increase in anti-HBs from below 10 IU/L to levels corresponding to protective immunity. We conclude that this vaccination strategy is effective throughout the first decade of life in avoiding chronic infection and in maintaining a good serological response.

Hepatitis B prophylaxis in newborns: A cross-sectional study of 7-year attendance in a public hospital of Brazil

BACKGROUND

Children with vertically transmitted hepatitis B virus develop chronic infection up to 90% of the time. This study aimed to verify the prevalence of hepatitis B surface antigen (HBsAg) in pregnant patients treated in a Brazilian public hospital and analyze the prophylactic measures in newborns.

METHODS

A cross-sectional study was conducted by collcting data in the electronic charts of patients who attended the obstetric and maternity departments, from January 1, 2010, to December 31, 2016, and evaluating the results of pregnant women's HBsAg, prophylaxis in newborns, and clinical follow-up. The data were tabulated and analyzed using Microsoft Excel software.

RESULTS

Among the 7,763 participating patients, 109 were reactive to HBsAg, and 3 were indeterminate. However, only 28 had correct information on HBV prophylaxis with the parturient and newborn in the chart, and only 16 completed the follow-up.

CONCLUSIONS

Most of the HBsAg-positive pregnant women (75%) did not have prophylactic information in the charts, and almost 50% of the pregnant women and newborns who had appropriate prophylaxis did not return for medical follow-up. Failure of prophylaxis can promote vertical/perinatal transmission of hepatitis B virus in newborns of mothers who are HBsAg positive.

Robust in vitro assay for analyzing the neutralization activity of serum specimens against hepatitis B virus

Anti-HBs is a well-known marker of protective capability against HBV. However, little is known about the association between the qAnti-HBs determined by immunoassays and the neutralization activity (NAT) derived from functional assays. We developed an in vitro assay for direct measurement of the NAT of human sera. The new assay was highly sensitive, with an analytical sensitivity of 9.6 ± 1.3 mIU/mL for the HBIG standard. For serum detection, the maximum fold dilution required to produce ≥50% inhibition (MDF₅₀) of HBV infection was used as the quantitative index. In vitro NAT evaluations were conducted for a cohort of 164 HBV-free healthy individuals. The results demonstrated that the NAT positively correlated with the qAnti-HBs (R² = 0.473, p < 0.001). ROC analysis indicated that the optimal cutoff value of the qAnti-HBs to discriminate significant NAT (MDF₅₀ ≥ 8) was 62.9 mIU/mL, with an AUROC of 0.920. Additionally, we found that the qAnti-HBc was another independent parameter positively associated with the NAT (R² = 0.300, p < 0.001), which suggested that antibodies against other HBV proteins generated by previous HBV exposure possibly also contribute to the NAT. In summary, the new cell-based assay provides a robust tool to analyse the anti-HBV NAT. Abbreviations: HBV: Hepatitis B virus; HBsAg: Hepatitis B surface antigen; Anti-HBs: Hepatitis B surface antibody; HBeAg: Hepatitis B e antigen; Anti-HBc: Hepatitis B core antibody; qAnti-HBs: quantitative hepatitis B surface antibody; qAnti-HBc: quantitative hepatitis B core antibody; qHBeAg: quantitative hepatitis B e antigen; NAT: neutralization activity; HBIG: hepatitis B immune globulin; NTCP: Na⁺-taurocholate cotransporting polypeptide; IRES: internal ribosome entry site; ccHBV: cell culture derived hepatitis B virus; GE/cell: genome equivalent per cell; MOI: multiplicity of infection; Dpi: day post infection; HepG2-TetOn: a HepG2-derived cell line that expresses the doxycycline-regulated transactivator; ROC: receiver operating characteristic curve; AUROC: area under receiver operating characteristic curve; LLOQ: the lower limits of quantification; MDF₅₀: the maximum fold dilution required to produce ≥50% inhibition; IC50: half maximal inhibitory concentration.

Serologic testing of randomly selected children after hepatitis B vaccination: a cross-sectional population-based study in Lao People's Democratic Republic

BACKGROUND

Population immunity against hepatitis B virus (HBV) in Lao People's Demographic Republic (PDR) has not been examined since the national HBV vaccination program was started in 2002. Vaccine has been observed to be frozen at times during cold-chain transport in vaccination programs in Lao PDR and other developing countries, which will inactivate the vaccine. Therefore, this study used post-vaccination serologic testing to evaluate the effects of HBV immunization in Lao PDR.

METHODS

A cross-sectional serologic study was conducted among children (age range, 5-9 years) and mothers (15-45 years) who were randomly selected using probability-proportional-to-size sampling from central Lao PDR. Blood samples were collected as dried blood spots (DBS) and analyzed using chemiluminescent microparticle immunoassay to detect anti-hepatitis B surface (HBs) titers. We also evaluated the correlation between anti-HBs levels measured in DBS and serum among healthy healthcare workers in Vientiane.

RESULTS

Anti-HBs titers from DBS were strongly correlated with serum levels (correlation coefficient = 0.999) in all 12 healthcare workers evaluated. A linear regression model showed that 10 mIU/mL of serum anti-HBs was equivalent to 3.45 mIU/mL (95% CI: 3.06-3.85) of DBS. Among 911 mother-child pairs tested, 171 children had documentation of vaccination. Of the 147 children who had received ≥3 doses of the hepatitis B vaccine, 1 (0.7%) was positive for anti-HBs. The remaining 24 children received the hepatitis B vaccine only twice, once or no dose.

CONCLUSIONS

The results showed extremely low positivity for anti-HBs among vaccinated children in central Lao PDR. Therefore, post-vaccination serologic testing is important to evaluate population immunity against HBV infection. DBS testing is a potential low-cost tool to evaluating the effectiveness of HBV vaccination programs.

Long-term immunogenicity of hepatitis B vaccine and impact of a booster dose on health care

Background: Accidental exposure to sharp instruments is an important problem for health care students. Thus, the aim of this study was to determine the rate of immunity in health care students 2 decades after national neonatal hepatitis B (HB) vaccination.

Methods: All junior students attending medicine, nursing and midwifery schools were screened for anti-HBs. One dose of hepatitis B vaccine was offered to all participants who did not have antibodies to HB surface antigen (anti-HBs) of > 10 IU/L; then, they were tested for anti-HBs after a month. The participants were classified into 3 groups: postboosting nonimmune, postboosting immune, and preboosting immune. Chi square test and ANOVA were used for data analysis.

Results: In the first step, 65.20% of participants did not show immunity, but after receiving a booster dose, only 6.0% remained nonimmune. The mean age of nonimmune students was significantly higher than that of students who had postboosting immune and preboosting immune status (p=0.001 and 0.002, respectively). Also, the mean injection time from last shot was higher in postboosting immune group compared to preboosting immune group (p<0.001). Also, prebooster anti-HBs level was significantly different among participants with suboptimal response and those who developed anamnestic response, indicating preserved immune memory (p=0.001).

Conclusion: High anamnestic response to HBV booster dose indicates sufficient immunity to HBV in the majority of health care students. However, identifying students who cannot respond to a booster dose of vaccine seems to be necessary at the beginning of health care courses.

Immunoglobulin G subclass and antibody avidity responses in Malian children immunized with Plasmodium falciparum apical membrane antigen 1 vaccine candidate FMP2.1/AS02A

BACKGROUND

A malaria vaccine based on Plasmodium falciparum apical membrane antigen 1 (AMA1) elicited strain specific efficacy in Malian children that waned in the second season after vaccination despite sustained AMA1 antibody titers. With the goal of identifying a humoral correlate of vaccine-induced protection, pre- and post-vaccination sera from children vaccinated with the AMA1 vaccine and from a control group that received a rabies vaccine were tested for AMA1-specific immunoglobulin G (IgG) subclasses (IgG1, IgG2, IgG3, and IgG4) and for antibody avidity.

METHODS

Samples from a previously completed Phase 2 AMA1 vaccine trial in children residing in Mali, West Africa were used to determine AMA1-specific IgG subclass antibody titers and avidity by ELISA. Cox proportional hazards models were used to assess correlation between IgG subclass antibody titers and risk of time to first or only clinical malaria episode and risk of multiple episodes. Asexual P. falciparum parasite density measured for each child as area under the curve were used to assess correlation between IgG subclass antibody titers and parasite burden.

RESULTS

AMA1 vaccination did not elicit a change in antibody avidity; however, AMA1 vaccinees had a robust IgG subclass response that persisted over the malaria transmission season. AMA1-specific IgG subclass responses were not associated with decreased risk of subsequent clinical malaria. For the AMA1 vaccine group, IgG3 levels at study day 90 correlated with high parasite burden during days 90-240. In the control group, AMA1-specific IgG subclass rise and persistence over the malaria season was modest and correlated with age. In the control group, titers of several IgG subclasses at days 90 and 240 correlated with parasite burden over the first 90 study days, and IgG3 at day 240 correlated with parasite burden during days 90-240.

CONCLUSIONS

Neither IgG subclass nor avidity was associated with the modest, strain-specific efficacy elicited by this blood stage malaria vaccine. Although a correlate of protection was not identified, correlations between subclass titers and age, and correlations between IgG subclass titers and parasite burden, defined by area under the curve parasitaemia levels, were observed, which expand knowledge about IgG subclass responses. IgG3, known to have the shortest half-life of the IgG subclasses, might be the most temporally relevant indicator of ongoing malaria exposure when examining antibody responses to AMA1.

Transcriptome analysis of immune genes in peripheral blood mononuclear cells of young foals and adult horses

During the neonatal period, the ability to generate immune effector and memory responses to vaccines or pathogens is often questioned. This study was undertaken to obtain a global view of the natural differences in the expression of immune genes early in life. Our hypothesis was that transcriptome analyses of peripheral blood mononuclear cells (PBMCs) of foals (on day 1 and day 42 after birth) and adult horses would show differential gene expression profiles that characterize natural immune processes. Gene ontology enrichment analysis provided assessment of biological processes affected by age, and a list of 897 genes with ≥2 fold higher (p<0.01) expression in day 42 when compared to day 1 foal samples. Up-regulated genes included B cell and T cell receptor diversity genes; DNA replication enzymes; natural killer cell receptors; granzyme B and perforin; complement receptors; immunomodulatory receptors; cell adhesion molecules; and cytokines/chemokines and their receptors. The list of 1,383 genes that had higher (p<0.01) expression on day 1 when compared to day 42 foal samples was populated by genes with roles in innate immunity such as antimicrobial proteins; pathogen recognition receptors; cytokines/chemokines and their receptors; cell adhesion molecules; co-stimulatory molecules; and T cell receptor delta chain. Within the 742 genes with increased expression between day 42 foal and adult samples, B cell immunity was the main biological process (p = 2.4E-04). Novel data on markedly low (p<0.0001) TLR3 gene expression, and high (p≤0.01) expression of IL27, IL13RA1, IREM-1, SIRL-1, and SIRPα on day 1 compared to day 42 foal samples point out potential mechanisms of increased susceptibility to pathogens in early life. The results portray a progression from innate immune gene expression predominance early in life to adaptive immune gene expression increasing with age with a putative overlay of immune suppressing genes in the neonatal phase. These results provide insight to the unique attributes of the equine neonatal and young immune system, and offer many avenues of future investigation.

Hepatitis B vaccination using a dissolvable microneedle patch is immunogenic in mice and rhesus macaques

Chronic Hepatitis B virus infection remains a major global public health problem, accounting for about 887,000 deaths in 2015. Perinatal and early childhood infections are strongly associated with developing chronic hepatitis B. Adding a birth dose of the hepatitis B vaccine (HepB BD) to routine childhood vaccination can prevent over 85% of these infections. However, HepB BD coverage remains low in many global regions, with shortages of birth attendants trained to vaccinate and limited HepB BD supply at birth. To address the challenges, we developed coated metal microneedle patches (cMNPs) and dissolvable microneedle patches (dMNPs) that deliver adjuvant‐free hepatitis B vaccine to the skin in a simple‐to‐administer manner. The dMNP contains micron‐scale, solid needles encapsulating vaccine antigen and dissolve in the skin, generating no sharps waste. We delivered HepB BD via cMNP to BALB/c mice and via dMNP to both mice and rhesus macaques. Both cMNP and dMNP were immunogenic, generating hepatitis B surface antibody levels similar to human seroprotection. Biomechanical analysis showed that at high forces the microneedles failed mechanically by yielding but microneedles partially blunted by axial compression were still able to penetrate skin. Overall, this study indicates that with further development, dMNPs could offer a method of vaccination to increase HepB BD access and reduce needle waste in developing countries.

Elimination of Vertical Transmission of Hepatitis B in Africa: A Review of Available Tools and New Opportunities

PURPOSE

This review article focuses on preventing vertical transmission of hepatitis B virus (HBV) among pregnant women living in sub-Saharan Africa (SSA), where disease is endemic and the estimated maternal HBV seroprevalence is >8%. Available interventions that have been studied in low- and middle-income countries are compared in terms of efficacy and effectiveness in clinical practice. Global disease-elimination targets, barriers to HBV-prevention efforts, and critical research gaps are discussed.

METHODS

A PubMed literature search in February 2018 identified relevant studies of interventions to reduce or prevent the transmission of HBV during pregnancy or in the peripartum period. Studies that focused on interventions that are currently available or could be made available in SSA were included. Trials conducted in SSA and other low-income countries were prioritized, although studies of interventions in middle- and high-income countries were included.

FINDINGS

Among 127 studies and reports included in the review, 60 included data from SSA. The most cost-effective intervention to reduce HBV infection rates in SSA is timely birth-dose vaccination followed by completion of the 3-dose infant-vaccination series. The identification and treatment of pregnant women with elevated HBV viral load to further reduce the risk for vertical transmission in SSA show promise, but efficacy and tolerability trials in Africa are lacking.

IMPLICATIONS

Scale-up of currently available tools is required to reach HBV disease-elimination goals in SSA. Many countries in SSA are in the process of rolling out national birth-dose vaccination campaigns; this roll out provides an opportunity to evaluate and improve processes in order to expand coverage. Early antenatal care, promotion of facility deliveries, and increased awareness of HBV prevention are also key components of prevention success. Future studies in SSA should identity an HBV-prevention package that is effective, well tolerated, and feasible and can be administered in the antenatal clinic and tailored to vertical-transmission risk.

Mother-to-child transmission of hepatitis B: Examining viral cut-offs, maternal HBsAg serology and infant testing

BACKGROUND & AIMS

Antipartum antiviral therapy in the setting of high viral load is recommended to prevent mother-to-child transmission of hepatitis B although recommended viral load cut-offs vary. Quantitative HBsAg has been proposed as an alternative screening strategy to identify high viral load in this setting. Guidelines suggest testing all infants for vaccine response and infection. We set out to re-examine viral load cut-offs; the predictive value of quantitative HBsAg and the need for follow-up infant testing in our cohort.

METHODS

A retrospective cohort study of 469 HBsAg positive mother-baby pairs from 2 tertiary hospitals in Sydney was performed. Antiviral therapy (lamivudine or tenofovir disoproxil fumarate) was offered to women with viral load ≥6 log₁₀  IU/mL (high) from 32 weeks gestation. Transmission and vaccine response was analysed according to viral load. The utility of quantitative HBsAg in identifying high viral load was examined.

RESULTS

Mother-to-child transmission only occurred in setting of high viral load, in 0.85% (1/117) of those who received antiviral therapy and in 8.66% (2/23) of those who chose not to. Quantitative HBsAg did not accurately identify high-risk mothers HBV DNA ≥6 log₁₀  IU/mL. Successful infant vaccine response was 98.7% overall, and 99.4% when viral load was <6 log₁₀  IU/mL.

CONCLUSION

Antiviral therapy initiated at 32 weeks when maternal viral load is ≥6 log₁₀  IU/mL almost completely abrogates transmission. Quantitative HBsAg does not reliably predict high viral load. When maternal viral load is <6 log₁₀  IU/mL, high vaccine efficacy and zero transmission suggests testing infants is of little value.

High coverage of hepatitis B vaccination and low prevalence of chronic hepatitis B in migrant children dictate a new catch-up vaccination strategy

BACKGROUND

Worldwide coverage of hepatitis B (HB) vaccination is increasing. This should be considered when determining the best strategy for catch-up HB vaccination in migrant children, who rarely have written proof of past immunizations. This study aimed to estimate HB vaccine protection, chronic HB prevalence and to identify determinants of vaccine protection.

METHODS

Newly arrived migrant children at Lausanne University Hospital from October 2014 to July 2017 were prospectively enrolled. Children and adolescents aged 1-18 years were approached for inclusion if they had no proof of past vaccinations and accepted a single dose of injected HB vaccine. HB surface antibody (anti-HBs) serology was performed after 4-6 weeks. Anti-HBs ≥100 IU/L were considered consistent with a booster-type antibody response. Patients with anti-HBs <100 IU/L received additional dose(s) of HB vaccine, after exclusion of chronic HB in children with anti-HBs <10 IU/L. Potential determinants of vaccine response were compared between children with and without booster-type response.

RESULTS

Two hundred children were available for analysis. Median age was 8.9 years (IQR 4.8-12.9), and 97 (49%) were female. The majority (n = 124, 62%) came from the region classified by the WHO as eastern Mediterranean. One hundred and sixty-one children (81%) had a booster-type antibody response. Only 1 patient (<1%) had chronic HB. In the multivariate analysis, younger age (OR per decreasing-year, 1.28; 95%CI, 1.05-1.57; p = 0.017) and migration from an urban area (OR 1.16; 95%CI, 1.01-1.33; p = 0.043) were the only significant determinants of booster-type response.

CONCLUSION

Post-vaccine serology may be used to identify a high proportion of individuals in our pediatric migrant population with previous immunization for HB. Our study also showed extremely low prevalence of chronic HB. No variable could definitively determine the results of serology. Post-vaccine serology represents the most effective strategy in this context of high vaccine coverage.

From infancy and beyond… ensuring a lifetime of hepatitis B virus (HBV) vaccine-induced immunity

Despite the long-term efficacy and immune persistence observed following HBV vaccination of infants, the need for a booster dose following infant immunization continues to be deliberated. Evidence from HBV booster dose response studies and long-term immunization program reviews are the basis for the recommendation that a vaccine booster is not necessary. However, further studies continue to emerge and highlight the need for standardization among observational studies in order to appropriately compare outcomes. There is an assumption that neonatal and infant (within 12 months of age) vaccine immune responses are equivalent; however, evidence exists for distinct vaccine responses within the first year of life. HBV vaccine programs have evolved over time, particularly regarding the type and dosage of vaccine used. Several universal neonatal immunization programs initially incorporated a 2.5 μg dosage (Recombivax-HB, Merck). This dosage has been shown in multiple long-term studies and meta-analyses to be associated with a lower primary response, decreased antibody persistence over time, and a reduced booster response 10 to 20 years following immunization. Ongoing surveillance of this and other HBV neonatally-vaccinated populations, particularly in low endemic regions, is necessary to understand the impact on long-term protection in order to ensure lifelong protection against hepatitis B infection.

Cost Analysis of Single-Dose Hepatitis B Revaccination Among Infants Born to Hepatitis B Surface Antigen-Positive Mothers and Not Responding to the Initial Vaccine Series

OBJECTIVES

Infants born to mothers who are hepatitis B surface antigen (HBsAg) positive are at risk for perinatal hepatitis B infection. As prevention, these infants receive a series of 3 or 4 doses of hepatitis B vaccine starting at birth and postvaccination serologic testing. Infants with antibody levels <10 mIU/mL are considered vaccine nonresponders and should be revaccinated. The objective of this cost analysis was to assess a single-dose revaccination strategy among infant nonresponders.

METHODS

We used a decision analytic tree to compare the costs of a single-dose revaccination strategy with the costs of a 3-dose revaccination strategy. The analysis consisted of 3 epidemiologic scenarios that varied levels of previous protection among infants indicated for revaccination. We assumed health outcomes in each strategy were the same, and we evaluated costs from the societal perspective using 2016 US dollars. We conducted sensitivity analyses on key variables, including the minimum required efficacy of a single revaccination dose.

RESULTS

In all analyses, the single-dose revaccination strategy was a lower-cost option than the 3-dose revaccination strategy. Under the assumption that all revaccination visits were previously unscheduled, single-dose revaccination reduced the cost per infant by $119.81 to $155.72 (depending on the scenario). Across all scenarios, the most conservative estimate for the threshold efficacy (the minimum efficacy required to result in a lower-cost option) value of single-dose revaccination was 67%.

CONCLUSIONS

For infants who were born to HBsAg-positive mothers and who were not responding to the initial vaccine series, a single-dose revaccination strategy, compared with a 3-dose revaccination strategy, reduced costs across several scenarios. These results helped inform the Advisory Committee on Immunization Practices' vote in February 2017 to recommend single-dose revaccination.

Early and long term anamnestic response to HBV booster dose among fully vaccinated Egyptian children during infancy

OBJECTIVE

To evaluate early and long term anamnestic response to a booster dose of HBV vaccine among non-seroprotected children.

SUBJECTS AND METHOD

A national community based project was carried out on 3600 children aged 9 months to 16 years, fully vaccinated during infancy. They were recruited from 6 governorates representing Egypt. It revealed that 1535 children (42.8%) had non sero-protective anti-HBs (<10 IU/L) and were HBsAg or anti-HBc negative. A challenging dose of 10 μg of mono-valent Euvax HBV vaccine was given to 1121/1535 children. Quantitative assessment of anti-HBs was performed to detect early (2-4 weeks) and long term (one year) anamnestic responses.

RESULTS

Early anamnestic response developed among 967/1070 children (90.3%).Children having detectable anti-HBs (1-9 IU/L) significantly developed early anamnestic response (90%) compared to 85% with undetectable anti-HBs (<1 IU/L), P < 0.001. Multiple logistic analysis revealed that undetectable anti-HBs, living in rural residence and children aged 15-16 years were the most significant predicting risk factors for the absence of early anamnestic response (<10 IU/L), with AOR 2.7, 2.7 & 4.7 respectively. After one year, long term anamnestic response was absent among 15% of children who previously showed early response. Poor early anamnestic response and undetectable pre-booster anti-HBs were the significant predicting risk factors for absent long term anamnestic response, with AOR 18.7 & 2.7 respectively.

CONCLUSION

Immunological memory for HBV vaccine outlasts the presence of anti- HBs and HBV vaccination program provides effective long term protection even in children showing waning or undetectable concentrations of anti-HBs. This signifies no need for a booster dose especially to healthy children.

Prevention of Hepatitis B Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices

HEPATITIS B VIRUS (HBV) IS TRANSMITTED VIA BLOOD OR SEXUAL CONTACT. PERSONS WITH CHRONIC HBV INFECTION ARE AT INCREASED RISK FOR CIRRHOSIS AND LIVER CANCER AND REQUIRE MEDICAL CARE. THIS REPORT UPDATES AND SUMMARIZES PREVIOUSLY PUBLISHED RECOMMENDATIONS FROM THE ADVISORY COMMITTEE ON IMMUNIZATION PRACTICES (ACIP) AND CDC REGARDING THE PREVENTION OF HBV INFECTION IN THE UNITED STATES. ACIP RECOMMENDS TESTING ALL PREGNANT WOMEN FOR HEPATITIS B SURFACE ANTIGEN (HBSAG), AND TESTING HBSAG-POSITIVE PREGNANT WOMEN FOR HEPATITIS B VIRUS DEOXYRIBONUCLEIC ACID (HBV DNA); ADMINISTRATION OF HEPB VACCINE AND HEPATITIS B IMMUNE GLOBULIN (HBIG) FOR INFANTS BORN TO HBV-INFECTED WOMEN WITHIN 12 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES AND POSTVACCINATION SEROLOGIC TESTING; UNIVERSAL HEPATITIS B VACCINATION WITHIN 24 HOURS OF BIRTH, FOLLOWED BY COMPLETION OF THE VACCINE SERIES; AND VACCINATION OF CHILDREN AND ADOLESCENTS AGED <19 YEARS WHO HAVE NOT BEEN VACCINATED PREVIOUSLY. ACIP RECOMMENDS VACCINATION OF ADULTS AT RISK FOR HBV INFECTION, INCLUDING UNIVERSAL VACCINATION OF ADULTS IN SETTINGS IN WHICH A HIGH PROPORTION HAVE RISK FACTORS FOR HBV INFECTION AND VACCINATION OF ADULTS REQUESTING PROTECTION FROM HBV WITHOUT ACKNOWLEDGMENT OF A SPECIFIC RISK FACTOR. THESE RECOMMENDATIONS ALSO PROVIDE CDC GUIDANCE FOR POSTEXPOSURE PROPHYLAXIS FOLLOWING OCCUPATIONAL AND OTHER EXPOSURES. THIS REPORT ALSO BRIEFLY SUMMARIZES PREVIOUSLY PUBLISHED AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASEST GUIDELINES FOR MATERNAL ANTIVIRAL THERAPY TO REDUCE PERINATAL HBV TRANSMISSION.

Single dose HBsAg CS-γ-PGA nanogels induce potent protective immune responses against HBV infection

Hepatitis B virus (HBV) infection is a severe threat to public health, which can be prevented by prophylactic vaccination. Here, we tested nanogels carriers in the prophylactic effect of hepatitis B surface antigen (HBsAg) vaccine. HBsAg nanogels (Ng) were prepared using chitosan (CS) and poly-γ-glutamic acid (γ-PGA). Positively charged Ng (+) and negatively charged Ng (-) were prepared by adjusting the CS and γ-PGA proportion. Dendritic cells (DCs) maturation in mice immunized with HBsAg Ng (+) and HBsAg Ng (-) could be augmented in response to pAAV/HBV1.2 plasmid challenge. Single-dose immunization with HBsAg Ng (+) induced HBsAg specific-antibodies. HBsAg Ng (+) immunized mice cleared HBsAg and restored anti-HBs production after pAAV/HBV1.2 plasmid challenge. Single-dose HBsAg Ng (+) induced humoral and cellular immunity, and could induce effector memory T cells. Single-dose HBsAg Ng (-) favored the induction of cellular immunity, and induced central memory T cells and effector memory T cells. However, HBsAg elimination was similar between HBsAg Ng (+)- and HBsAg Ng (+) plus HBsAg Ng (-)-immunized mice. Zeta potential measurements showed that HBsAg Ng (+) were more stable than HBsAg Ng (-). Therefore, Ng (+) are desirable HBsAg prophylactic vaccine carriers, providing long-term protection against HBV, and are a good choice to study and apply weakly immunostimulatory antigens.

A retrospective study of hepatitis B mother-to-child transmission prevention and postvaccination serological test results of infants at risk of perinatal transmission in two counties of middle China

Approximately, 240 million people have chronic hepatitis B worldwide, with mother-to-child-transmission (MTCT) accounting for most cases. Therefore, Henan Province, China launched a public health programme to prevent MTCT. To determine the efficacy of this health programme, a survey was carried out in Huixian and Xinan counties, which are located in northern and western Henan. All infants born in these two counties between January 1, 2013 and March 31, 2014 to a mother positive for hepatitis B surface antigen (HBsAg) were surveyed. In total, there were 438 mother-infant pairs. A blood sample was collected from all mothers and infants and the following Hepatitis B virus (HBV) markers, antibodies, and antigens were measured: HBsAg, anti-HBs, anti-HBc, HBeAg, anti-HBe, and HBV-DNA. All mothers and 5.3% (23/438) of the infants were HBsAg positive. All infants received three doses of the hepatitis B vaccine (HepB) and the postvaccination serological test (PVST) showed that the appropriate interval for PVST may be 1-8 months after the final HepB dose. Multivariable analysis showed that infants without a timely first and second dose of the HepB, with an HBeAg-positive mother and mothers who had not received hepatitis B immune globulin during pregnancy were implicated in MTCT. The stratified analysis using maternal HBeAg as a marker showed that maternal HBeAg may be a strong risk factor for MTCT. To prevent MTCT in middle China, several courses of action are recommended. The first is to optimize the screening method for the mother to allow HBeAg and HBsAg-positive mothers to receive medical treatment during pregnancy and a timely birth dose of the vaccine to all infants. Second, all infants with an HBsAg-positive mother should be tested for anti-HBs and HBsAg at 7-14 months old and any anti-HBs-nonresponse infants should receive an additional three dosesof the vaccine.

The association of the vitamin D status with the persistence of anti-HBs antibody at 20years after primary vaccination with recombinant hepatitis B vaccine in infancy

BACKGROUND AND OBJECTIVE

Vitamin D has potent immunoregulatory effects due to the expression of its receptor on the majority of immune cells. The aim was to evaluate the association of the vitamin D status with the persistence of anti-HBs antibody and immune response to booster immunization at 20years after primary vaccination with hepatitis B (HB) vaccine.

METHODS

Blood samples were collected from 300 adults 20years after completion of the primary HB vaccination in infancy. The serum levels of vitamin D and anti-HBs antibody were measured by ELISA. A single booster dose of a recombinant HB vaccine was administered to a total of 138 subjects, whose anti-HBs titer was<10IU/L. The sera of revaccinated subjects were re-tested for anti-HBs antibody, 4weeks after booster vaccination.

RESULTS

At 20years after primary vaccination, the mean vitamin D concentrations were significantly higher in seroprotective subjects as compared to non-seroprotective individuals (P<0.01). The levels of anti-HBs were significantly increased with advanced concentrations of vitamin D (P<0.01). Overall, 125/138 (90.6%) of the revaccinated subjects showed an anamnestic response to booster vaccination. The concentrations of vitamin D were significantly higher in subjects with an anamnestic response to booster vaccination as compared with subjects without this response (P<0.01).

CONCLUSION

Vitamin D status may influence the persistence of anti-HBs antibody and durability of protection after primary vaccination with a recombinant HB vaccine in infancy.

Hepatitis B vaccine alone may be enough for preventing hepatitis B virus transmission in neonates of HBsAg (+)/HBeAg (-) mothers

BACKGROUND AND AIM

To prospectively evaluate the efficacy of vaccine alone compared with vaccine plus HBIG for preventing HBV transmission in neonates of HBsAg (+)/HBeAg (-) mothers.

METHODS

Combined immunization is currently recommended for neonates of HBsAg (+) mothers in China. As a result, a randomized design is infeasible due to ethical reasons. In practice, Guangxi Zhuang Autonomous Region and Jiangsu Province implement vaccine alone and vaccine plus HBIG strategies for neonates born to HBsAg (+)/HBeAg (-) mothers, respectively. We alternatively enrolled neonates of HBsAg (+)/HBeAg (-) mothers from these two regions. Three doses of a recombinant yeast-derived hepatitis B vaccine were given at 0, 1 and 6months with or without HBIG at birth.

RESULTS

At 7months, sera were collected from 132 neonates in Guangxi Zhuang Autonomous Region and 752 neonates in Jiangsu Province. Baseline characteristics of both mothers and neonates were comparable in the two regions. No differences were revealed regarding the occurrence of perinatal HBV transmission with or without HBIG at birth [0.1% (1/752) vs. 0.0% (0/132), p=1.000]. The anti-HBs response rates were 97.7% (129/132) and 98.5% (740/751) for the neonates with vaccine alone and with HBIG (p=0.758), respectively. Vaccine alone induced a significantly higher anti-HBs GMC as compared to vaccine plus HBIG at 7months of age (1555.3mIU/mL vs. 654.9mIU/mL, p<0.0001). At 12months of age, protective levels of anti-HBs remained in 97.4% (596/612) and 98.3% (118/120) of the neonates receiving and not receiving HBIG, respectively (p=0.771). The neonates receiving combined prophylaxis had a markedly lower anti-HBs GMC (210.7mIU/mL vs. 297.0mIU/mL, p=0.011). Horizontal HBV transmission occurred in none of the successfully immunized neonates for both compared groups at 12months of age.

CONCLUSIONS

Vaccine alone may be enough for preventing HBV transmission in neonates of HBsAg (+)/HBeAg (-) mothers.

Potential role of killer immunoglobulin receptor genes among individuals vaccinated against hepatitis B virus in Lebanon

AIM

To explore the role of killer immunoglobulin receptor (KIR) genes in responsiveness or non-responsiveness to vaccination against hepatitis B virus.

METHODS

We recruited 101 voluntary participants between March 2010 and December 2011. Sera samples from vaccinated and non-vaccinated participants were tested for the presence of anti-HBs antibodies as a measure of protection against hepatitis B, hepatitis B surface antigen and hepatitis B core antibody as indicators of infection by enzyme-linked immunosorbent assay. KIR gene frequencies were determined by polymerase chain reaction.

RESULTS

Sera samples from 99 participants were tested for the levels of anti-HBs as an indicator of protection (≥ 10 mIU/mL) following vaccination as defined by the World Health Organization international reference standard. Among the vaccinated participants, 47% (35/74) had anti-HBs titers above 100 mIU/mL, 22% (16/74) had anti-HBs ranging between 10-100 mIU/mL, and 20% (15/74) had values of less than 10 mIU/mL. We report the lack of significant association between the number of vaccine dosages and the titer of antibodies among our vaccinated participants. The inhibitory KIR2DL1, KIR2DL4, KIR3DL1, KIR3DL2, and KIR3DL were detected in more than 95%, whereas KIR2DL2, KIR2DL3, KIR2DL5 (KR2DL5A and KIR2DL5B) were expressed in 56%, 84% and 42% (25% and 29%) of participants, respectively. The observed frequency of the activating KIR genes ranged between 35% and 55% except for KIR2DS4, detected in 95% of the study participants (40.6% 2DS4*001/002; 82.2% 2DS4*003/007). KIR2DP1 pseudogene was detected in 99% of our participants, whereas KIR3DP*001/02/04 and KIR3DP1*003 had frequencies of 17% and 100%, respectively. No association between the frequency of KIR genes and anti-HBs antibodies was detected. When we compared the frequency of KIR genes between vaccinated individuals with protective antibodies titers and those who lost their protective antibody levels, we did not detect a significant difference. KIR2DL5B was significantly different among different groups of vaccinated participants (group I > 100 mIU/mL, group II 10-100 mIU/mL, group III < 10 mIU/mL and group IV with undetectable levels of protective antibodies).

CONCLUSION

To our knowledge, this is the first study screening for the possible role of KIR genes among individuals vaccinated against hepatitis B virus (HBV). Our results can be used to design larger studies to better understand the role of KIR genes in protection against or susceptibility to HBV post vaccination.