Maternal immunization promotes the immune response of neonates towards hepatitis B vaccine

The Immunogenicity of a VLP-based Malaria Vaccine Targeting CSP in Pregnant and Neonatal Mice

Maternal antibodies are passively transferred to the fetus via the placenta during gestation and can play an important role in protecting the newborn from infection. For example, in malaria-endemic regions, maternal antibodies likely provide substantial protection against Plasmodium falciparum malaria in the first 6 months of life. However, circulating maternal antibodies can also interfere with vaccine efficacy. Here, we used a mouse maternal transfer model to evaluate whether maternal antibodies interfere with the responsiveness to a virus-like particle (VLP)-based vaccine targeting the CIS43 epitope of the malaria circumsporozoite protein (CSP). We found immunized dams passively transfer to pups high levels of anti-CSP IgG antibodies that steadily decline as the animals age. We also found that the neonatal offspring of immunized mice do not respond to de novo immunization with the CIS43-targeted VLP vaccine until maternal antibody titers decline below an inhibitory threshold. These findings may have important implications for delineating the delicate balance between protection conferred by maternal antibodies and the offspring's ability to respond to immunization.

Evaluation of factors associated the expression of anti-HBs in children in Hunan Province, China

BACKGROUND AND OBJECTIVES

Vaccine is the most essential avenue to prevent hepatitis B virus (HBV) infection in infants and preschool children in China, with the largest populations carrying HBV in the world. This study aimed to evaluate the factors associating the response level of anti-HBs in children, providing instructions for HBV prevention clinically.

METHODS

The children taking physical examinations in the Third Xiangya Hospital from January 2013 to April 2020 were recruited. Telephone follow-up were adopted to collect further information. Univariate logistic regression was used to analyse the relationship between age and anti-HBs expression. Grouping by age and anti-HBs expression, we used chi-square test and T test to compare qualitative and quantitative data between positive group and negative group in each age subgroup. The meaningful variables (P < 0.10) in chi-square test or T test were further assessed with collinearity and chosen for univariate and multivariate logistic regression analysis by the stepwise backward maximum likelihood method (α_in = 0.05, α_out = 0.10).

RESULTS

A total of 5838 samples (3362 males, 57.6%) were enrolled. In total, the incidence of negative anti-HBs increased with age[OR = 1.037(1.022-1.051)]. Multivariate logistic regression analysis illustrated that anemia[OR = 0.392(0.185-0.835)], age[OR = 2.542(1.961-3.295)] and Vit D[OR = 0.977(0.969-0.984)] in 0.5-2.99 years subgroup, Zinc deficiency[OR = 0.713(0.551-0.923] and age[OR = 1.151(1.028-1.289)] in 3-5.99 years subgroup, Vit D[OR = 0.983(0.971-0.995)] in 12-18 years subgroup had significant association with anti-HBs.

CONCLUSIONS

This retrospective study illustrated that age, anemia status, zinc deficiency and vitamin D were associated with anti-HBs expression in specific age groups of children, which could serve as a reference for the prevention of HBV.

The effects of increased dose of hepatitis B vaccine on mother-to-child transmission and immune response for infants born to mothers with chronic hepatitis B infection: a prospective, multicenter, large-sample cohort study

BACKGROUND

Appropriate passive-active immunoprophylaxis effectively reduces mother-to-child transmission (MTCT) of hepatitis B virus (HBV), but the immunoprophylaxis failure was still more than 5% under the current strategy. The study objective was to investigate the effects of high dose of HB vaccine on MTCT and immune response for infants born to hepatitis B surface antigen (HBsAg)-positive mothers.

METHODS

This was a prospective, multicenter, large-sample cohort study in four sites of China, and 955 pairs of HBsAg-positive mothers and their infants were enrolled in our investigation. The infants were given 10 μg or 20 μg HB vaccine (at age 0, 1, and 6 months) plus HB immunoglobulin (at age 0 and 1 month). Serum HBsAg, antibody to HBsAg (anti-HBs), and/or HBV DNA levels in the infants were determined at age 12 months. The safety of 20 μg HB vaccine was evaluated by adverse events and observing the growth indexes of infants.

RESULTS

Thirteen of 955 infants were HBsAg-positive at 12 months. Stratification analysis showed that immunoprophylaxis failure rates in the 20 μg group were not significantly different from the 10 μg group, whatever maternal HBV load was high or not. But the high dose of HB vaccine significantly reduced low-response rate (anti-HBs 10-100 IU/L) (P = 0.002) and middle-response rate (anti-HBs 100-1000 IU/L) (P = 0.022) and improved high-response rate (anti-HBs ≥ 1000 IU/L) (P < 0.0001) in infants born to mothers with HBV DNA < 5 log₁₀ IU/mL. For infants born to mothers with HBV DNA ≥ 5 log₁₀ IU/mL, 20 μg HB vaccine did not present these above response advantages. The 20 μg HB vaccine showed good safety for infants.

CONCLUSIONS

The 20 μg HB vaccine did not further reduce immunoprophylaxis failure of infants from HBsAg-positive mothers, but increased the high-response and decreased low-response rates for infants born to mothers with HBV DNA < 5 log₁₀ IU/mL.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR-PRC-09000459.

Serum Cytokeratin 18 M30 Levels in Chronic Hepatitis B Reflect Both Phase and Histological Activities of Disease

Chronic hepatitis B has highly a dynamic course with significant fluctuations of HBV-DNA and ALT impeding assessment of disease activity. New biomarkers of inflammatory versus noninflammatory stages of HBV infection are urgently needed. Cytokeratin 18 epitope M30 (M30 CK-18) is a sensitive marker of cell death. We aimed to investigate an association between serum M30 CK-18 and histological activity and phase of HBV infection. 150 Caucasian patients with HBV-infection were included in the study. Serum M30 CK-18 levels reflected phase of disease, being significantly higher in both HBeAg(+) and HBeAg(−) hepatitis B in comparison to HBsAg(+) carrier groups. The highest serum M30 CK-18 levels were observed in subjects with the most advanced stages of HBV. Moreover, its serum concentrations correlated with both inflammatory activity and fibrosis advancement (ANOVA P < 0.001). Importantly, serum M30 CK-18 levels were able to discriminate patients with mild versus moderate-advanced fibrosis (AUC: 0.86) and mild versus active liver inflammation (AUC: 0.79). M30 CK-18 serum concentration has good sensitivity and specificity in discriminating mild versus moderate/severe fibrosis and inflammation even in patients with normal ALT activity. This study suggests M30 CK-18 as a potential noninvasive marker of disease activity and also a marker of phase of persistent HBV infection.

Maternal anti-HBVs suppress the immune response of infants to hepatitis B vaccine

It is still controversial whether maternal anti-HBV antibodies (anti-HBVs) affect the infants' immune response to hepatitis B virus (HBV) vaccination. This multicentre study aims to address this question. First, we determined whether the transplacental transfer of maternal anti-HBVs occurs by measuring the titres of 90 anti-HBVs-positive pregnant women and their newborns. The anti-HBVs-positive rates of newborns ranged from 89.7% to 100.0%, depending on the maternal anti-HBVs titres. Secondly, we investigated the effects of maternal anti-HBVs on the immune response of infants to HBV vaccination. A total of 1063 mother-and-infant pairs were enrolled and divided into three groups with maternal anti-HBVs titres of <10 IU/L (negative - 37.9%), 10-499 and ≥500 IU/L. The infants' anti-HBVs-positive rate and titres were negatively correlated with maternal anti-HBVs titres: the anti-HBVs-positive rate of infants were 88.9% (360/405), 84.5% (381/451) and 77.3% (160/207) in mothers with low, intermediate and high antibody titres, respectively, P<.0001. Median titres of anti-HBVs (IU/L) among infants were 169.1, 141.0 and 79.4, respectively, P=.020. One hundred and sixty-two infants were negative for anti-HBVs after the standard vaccination, and 120 of 131 of these infants (91.6%) reached anti-HBVs positivity after the first "booster" dose. The maternal anti-HBVs titres did not significantly affect infant response to this booster. In summary, transplacental transfer of anti-HBVs occurs and high titres of maternal anti-HBVs may suppress the immune response of infants to the standard HBV vaccination. The current schedule of the 0, 1 and 6 month may not be the optimal choice of infants with anti-HBVs-positive mothers.

Economic evaluation of HBV vaccination: A systematic review of recent publications (2000-2013)

AIM

To conduct a systematic review of the economic evaluations (EE) of HBV vaccination, taking also into account the studies published in the new millennium.

METHODS

An extensive scientific literature review was conducted using two electronic medical journal databases: Scopus and PubMed engines for published studies on EE of HBV vaccination.

RESULTS

22 articles were reviewed, 9, 5 and 8 cost-effectiveness, cost-benefit and cost-utility analysis, respectively. Studies were mainly concerning EE of universal vaccination (UV), mostly with regards to low or low-medium income countries. For high income countries, EE were focused on the possible implementation of HBV vaccination in particular settings, such as diabetic, renal and other chronic conditions care, as well as infectious diseasesUV has usually a very good cost-effectiveness ratio (80%), ranging from cost-saving (China) or few Euro per LY/QALY gained (in Thailand, and Vietnam) to 630.00$/QALY in USA (Asian and Pacific Islands) Moreover, EE of HBV vaccination are favorable in the infectious diseases field as well as for chronic conditions. In relation to diabetes the studies gave controversial results.

CONCLUSION

This systematic review highlighted the importance of introducing HBV vaccination not only for infant UV program but also for other settings in which patients are people affected by communicable and non-communicable diseases.

Development of immunity in early life

The immune system in early life goes through rapid and radical changes. Early life is also the period with the highest risk of infections. The foetal immune system is programmed to coexist with foreign antigenic influences in utero, and postnatally to rapidly develop a functional system capable of distinguishing helpful microbes from harmful pathogens. Both host genetics and environmental influences shape this dramatic transition and direct the trajectory of the developing immune system into early childhood and beyond. Given the malleability of the immune system in early life, interventions aimed at modulating this trajectory thus have the potential to translate into considerable reductions in infectious disease burden with immediate as well as long-lasting benefit. However, an improved understanding of the underlying molecular drivers of early life immunity is prerequisite to optimise such interventions and transform the window of early life vulnerability into one of opportunity.