The immunogenicity of GSK’s recombinant hepatitis B vaccine in children: a systematic review of 30 years of experience

Persistence of antibodies 5 years after hepatitis B vaccination in preterm birth children: A retrospective cohort study using real-world data

Previous studies did not provide substantial evidence for long-term immune persistence after the hepatitis B vaccine (HepB) in preterm birth (PTB) children. Consequently, there is ongoing controversy surrounding the booster immunization strategy for these children. Therefore, we conducted a retrospective cohort study to evaluate the disparities in immune persistence between PTB children and full-term children. A total of 1027 participants were enrolled in this study, including 505 PTB children in the exposure group and 522 full-term children in the control group. The negative rate of hepatitis B surface antibody (HBsAb) in the PTB group was significantly lower than that in the control group (47.9% vs. 41.4%, p = .035). The risk of HBsAb-negative in the exposure group was 1.5 times higher than that in the control group (adjusted odds ratio [aOR] = 1.5, 95% confidence interval [CI]: 1.1-2.0). The geometric mean concentration (GMC) of HBsAb was much lower for participants in the exposure group compared to participants in the control group (9.3 vs. 12.4 mIU/mL, p = .029). Subgroup analysis showed that the very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) had relatively low GMC levels of 3.2 mIU/mL (95% CI: 0.9-11.1) and 7.9 mIU/mL (95% CI: 4.2-14.8), respectively. Our findings demonstrated that PTB had a significant impact on the long-term persistence of HBsAb after HepB vaccination. The very preterm infants (gestational age <32 weeks) and the preterm low birth weight infants (birth weight <2000 g) may be special populations that should be given priority for HepB booster vaccination.

Bad Liver and a Broken Heart: Hepatitis B in the Newborn

Hepatitis B viral infection is a significant source of morbidity and mortality worldwide. The United States has experienced a precipitous drop in acute hepatitis B infection after the introduction and widespread adoption of recombinant vaccines. Neonates experience significant risk from both vertical and horizontal hepatitis B exposure during a period of immaturity of the innate and adaptive immune systems. Acquisition of hepatitis B virus at or near birth confers the highest lifetime risk of chronic infection and subsequent complications including liver cirrhosis and hepatocellular carcinoma. Pregnant women should be screened for the presence of hepatitis B surface antigen, indicating acute or chronic infection, and, if positive, hepatitis B viral deoxyribonucleic acid, allowing for quantification of viral load. The development of highly effective and safe recombinant vaccines allows partial protection of late preterm and term neonates immediately after birth. Additionally, administration of hepatitis B immune globulin in the setting of suspected or confirmed exposure supplements the immune response and decreases the risk of chronic infection. The optimal timing of vaccination is later in low-birth-weight neonates due to the aforementioned immune system immaturity. Health care providers serving neonates must familiarize themselves with national guidelines regarding hepatitis B vaccination and hepatitis B immune globulin therapy. Understanding the risks of infection and the evidence basis supporting vaccination and immunotherapy will allow providers to educate families and support decision-making, with the potential to eradicate this vaccine-preventable illness in our lifetime.

Next-Generation TB Vaccines: Progress, Challenges, and Prospects

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is a prevalent global infectious disease and a leading cause of mortality worldwide. Currently, the only available vaccine for TB prevention is Bacillus Calmette-Guérin (BCG). However, BCG demonstrates limited efficacy, particularly in adults. Efforts to develop effective TB vaccines have been ongoing for nearly a century. In this review, we have examined the current obstacles in TB vaccine research and emphasized the significance of understanding the interaction mechanism between MTB and hosts in order to provide new avenues for research and establish a solid foundation for the development of novel vaccines. We have also assessed various TB vaccine candidates, including inactivated vaccines, attenuated live vaccines, subunit vaccines, viral vector vaccines, DNA vaccines, and the emerging mRNA vaccines as well as virus-like particle (VLP)-based vaccines, which are currently in preclinical stages or clinical trials. Furthermore, we have discussed the challenges and opportunities associated with developing different types of TB vaccines and outlined future directions for TB vaccine research, aiming to expedite the development of effective vaccines. This comprehensive review offers a summary of the progress made in the field of novel TB vaccines.

A booster hepatitis B vaccine for children with maternal HBsAg positivity before 2 years of age could effectively prevent vaccine breakthrough infections

Background

The long-term protective effect of hepatitis B vaccine (HepB), the incidence of hepatitis B virus (HBV) vaccine breakthrough infections (VBIs), and whether a booster HepB is necessary remain to be clarified in children born to mothers with chronic HBV infection.

Methods

Based on a long-term follow-up prospective cohort of 1177 hepatitis B surface antigen (HBsAg)-positive mothers and their paired infants which was established from 2009 to 2011, total 454 children with immunoprophylaxis success as determined by postvaccination serologic testing (PVST) at 7 months old were included in this study. Among the 454 children, 246 never had a booster HepB, and 208 children received a booster HepB from 1 to 5 years of age. Multivariate logistic regression analysis was used to analyse the risk factors for HBV VBIs.

Results

The hepatitis B surface antibody (anti-HBs) levels declined sharply from 7 months to 2 years old, and the anti-HBs seronegative rate in the children increased significantly from 2 years old. A total of 31 (6.83%) of the 454 children experienced VBIs, of which 7 had overt and 7 had occult HBV infections. Notably, 14 (45.16%) of the 31 children with VBIs were diagnosed at 2 years old, and all of them had anti-HBs positivity (> 10 mIU/mL) at 1 year old. Maternal hepatitis B e antigen (HBeAg) positivity, higher HBV DNA and HBsAg levels, lower initial infant anti-HBs levels and not receiving a booster HepB were independent risk factors for VBIs. The incidence of VBIs was significantly lower in children with a booster HepB than in nonboosted children (0.50 vs. 11.90%, P < 0.001), and none of the boosted children developed overt or occult HBV infection. The anti-HBs levels of 76.67% for the children with VBIs in the nonboosted group indicated positivity before VBIs was detected.

Conclusions

After the primary full immunization with HepB, children born to mothers with chronic HBV infection, especially the children with maternal HBeAg positivity, high HBV DNA levels, high HBsAg levels and/or low initial infant anti-HBs levels, were at a high risk of VBIs, and a booster HepB for these children before 2 years old, instead of when their anti-HBs level is < 10 mIU/mL, could reduce the incidence of VBIs.

Impact of industry sponsorship on the quality of systematic reviews of vaccines: a cross-sectional analysis of studies published from 2016 to 2019

BACKGROUND

Systematic reviews (SRs) provide the highest level of evidence and inform evidence-based decision making in health care. Earlier studies found association with industry to be negatively associated with methodological quality of SRs. However, this has not been investigated in SRs on vaccines.

METHODS

We performed a systematic literature search using MEDLINE and EMBASE in March 2020. The results were restricted to those published between 2016 and 2019 with no language restrictions. Study characteristics were extracted by one person and checked by an experienced reviewer. The methodological quality of the SRs was assessed with the AMSTAR 2 tool by multiple reviewers after a calibration exercise was performed. A summary score for each SR was calculated. The Mann-Whitney U test and Fisher's exact test were performed to compare both groups.

RESULTS

Out of 185 SRs that met all inclusion criteria, 27 SRs were industry funded. Those were matched with 30 non-industry funded SRs resulting in a total sample size of 57. The mean AMSTAR 2 summary score across all SRs was 0.49. Overall, the median AMSTAR 2 summary score was higher for the non-industry funded SRs than for the industry-funded SRs (0.62 vs. 0.36; p < .00001). Lower ratings for industry funded SRs were consistent across all but one AMSTAR 2 item, though significantly lower only for three specific items.

CONCLUSION

The methodological quality of SRs in vaccination is comparable to SRs in other fields, while it is still suboptimal. We are not able to provide a satisfactory explanation why industry funded SRs had a lower methodological quality than non-industry funded SRs over recent years. Industry funding is an important indicator of methodological quality for vaccine SRs and should be carefully considered when appraising SR quality.

The role of vaccines in combating antimicrobial resistance (AMR) bacteria

Most pathogens have developed an intrinsic capacity to thrive by developing resistance to antimicrobial compounds utilized in treatment. Antimicrobial resistance arises when microbial agents such as bacteria, viruses, fungi, and parasites alter their behaviour to make current conventional medicines inefficient. Vaccination is one of the most effective strategies to fight antimicrobial resistance. Vaccines, unlike drugs, are less likely to produce resistance since they are precise to their target illnesses. Vaccines against infectious agents such as Streptococcus pneumoniae and Haemophilus influenzae have already been shown to reduce tolerance to antimicrobial medications; however, vaccines against some antimicrobial-resistant pathogens such as Vibrio cholerae, Salmonella typhi, Escherichia coli, nosocomial infections, and pulmonary and diarrheal disease viruses require more research and development. This paper describes vaccine roles in combatting antimicrobial resistance, quantifies the overall advantages of vaccination as an anti-antimicrobial resistance approach, analyzes existing antimicrobial vaccines and those currently under development, and emphasizes some of the obstacles and prospects of vaccine research and development.

How does the immunogenicity of hepatitis B vaccine change over the years in childhood?

Hepatitis B is the leading cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. The incidence of HBV infection has significantly decreased with hepatitis B vaccination. Hepatitis B vaccine is administered to children at 0, 1 and 6 months of age according to the national schedule. There is a high rate of protective antibody (anti-HBs) development after hepatitis B vaccination. We conducted the study to investigate how the hepatitis B surface antibody (anti-HBs) positivity rates and the titers change over time in childhood following vaccination. Patients who presented at the general pediatric outpatient clinic of Yenimahalle Education and Training Hospital and the HBsAg and anti-HBs titers were tested for any reason between July 2011 and May 2018 were retrospectively evaluated. The cutoff level for protection by the anti-HBs titer was accepted as ≥10 mIU/mL with lower levels indicating no protection. Anti-HBs positivity was compared by age group. Anti-HBs levels were studied in 4326 children. The mean age of the included in the study was 127 ± 62 months. A protective anti-HBs level (≥10 mIU/mL) was present in 2292 children (69.2%). The highest anti-HBs antibody positivity rate was in the under 3 years' age group. The positivity rate significantly decreased after age 7 years. The HBsAg level was determined in all children in the study and five had a positive result. In conclusion, our study found that the anti-HBs positivity rate and the anti-HBs level decreased with age. However, the anti-HBs antibody result remained positive in more than half of the children.

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.

Rational Vaccine Design in Times of Emerging Diseases: The Critical Choices of Immunological Correlates of Protection, Vaccine Antigen and Immunomodulation

Vaccines are the most effective medical intervention due to their continual success in preventing infections and improving mortality worldwide. Early vaccines were developed empirically however, rational design of vaccines can allow us to optimise their efficacy, by tailoring the immune response. Establishing the immune correlates of protection greatly informs the rational design of vaccines. This facilitates the selection of the best vaccine antigens and the most appropriate vaccine adjuvant to generate optimal memory immune T cell and B cell responses. This review outlines the range of vaccine types that are currently authorised and those under development. We outline the optimal immunological correlates of protection that can be targeted. Finally we review approaches to rational antigen selection and rational vaccine adjuvant design. Harnessing current knowledge on protective immune responses in combination with critical vaccine components is imperative to the prevention of future life-threatening diseases.

Coverage with Timely Administered Vaccination against Hepatitis B Virus and Its Influence on the Prevalence of HBV Infection in the Regions of Different Endemicity

Universal hepatitis B vaccination of newborns was implemented in Russia starting from 1998. From 1998 to 2019, the incidence of acute hepatitis B reduced from 43.8 to 0.57 cases per 100,000 population. Here, we assessed the timely coverage of newborns with the birth dose (HepB-BD), second dose (HepB-2nd), and three vaccine doses (HepB3) in two remote regions of Russia with low (Belgorod Oblast) and high (Yakutia) levels of hepatitis B virus (HBV) endemicity. Vaccination data were obtained from the medical records of 1000 children in Yakutia and 2182 children in Belgorod Oblast. Sera of healthy volunteers from Belgorod Oblast (n = 1754) and Yakutia (n = 1072) across all age groups were tested for serological markers of HBV to assess the infection prevalence and herd immunity. Average HepB-BD coverage was 99.2% in Yakutia and 89.4% in Belgorod Oblast (p < 0.0001) and in both regions varied significantly, from 66% to 100%, between medical centers. The principal reason for the absence of HepB-BD was parent refusal, which accounted for 63.5% of cases of non-vaccination (83/123). While timely HepB-2nd coverage was only 55.4%–64.7%: HepB3 coverage by the age of one year exceeded 90% in both study regions. HBV surface antigen (HBsAg) prevalence in the 1998–2019 birth cohort was 0.2% (95% CI: 0.01–1.3%) in Belgorod Oblast and 3.2% (95% CI: 1.9–5.2%) in Yakutia. The proportion of persons testing negative for both antibodies to HBsAg (anti-HBs) and antibodies to HBV core antigen (anti-HBc) in the 1998–2019 birth cohort was 26.2% (125/481) in Belgorod Oblast and 32.3% (162/501) in Yakutia. We also assessed the knowledge of and attitude towards vaccination among 782 students and teachers of both medical and non-medical specialties from Belgorod State University. Only 60% of medical students knew that hepatitis B is a vaccine-preventable disease. Both medical and nonmedical students, 37.8% and 31.3%, respectively, expressed concerns about safety and actual necessity of vaccination. These data indicate the need to introduce a vaccine delivery audit system, improve medical education with respect to vaccination strategies and policies, and reinforce public knowledge on the benefits of vaccination.

The Role of Virus-Like Particles in Medical Biotechnology

Virus-like particles (VLPs) are protein-based, nanoscale, self-assembling, cage architectures, which have relevant applications in biomedicine. They can be used for the development of vaccines, imaging approaches, drug and gene therapy delivery systems, and in vitro diagnostic methods. Today, three relevant viruses are targeted using VLP-based recombinant vaccines. VLP-based drug delivery, nanoreactors for therapy, and imaging systems are approaches under development with promising outcomes. Several VLP-based vaccines are under clinical evaluation. Herein, an updated view on the VLP-based biomedical applications is provided; advanced methods for the production, functionalization, and drug loading of VLPs are described, and perspectives for the field are identified.

Vaccines Against Antimicrobial Resistance

In the last century, life expectancy has increased considerably, thanks to the introduction of antibiotics, hygiene and vaccines that have contributed to the cure and prevention of many infectious diseases. The era of antimicrobial therapy started in the nineteenth century with the identification of chemical compounds with antimicrobial properties. However, immediately after the introduction of these novel drugs, microorganisms started to become resistant through different strategies. Although resistance mechanisms were already present before antibiotic introduction, their large-scale use and mis-use have increased the number of resistant microorganisms. Rapid spreading of mobile elements by horizontal gene transfer such as plasmids and integrative conjugative elements (ICE) carrying multiple resistance genes has dramatically increased the worldwide prevalence of relevant multi drug-resistant human pathogens such as Staphylococcus aureus, Neisseria gonorrhoeae, and Enterobacteriaceae. Today, antimicrobial resistance (AMR) remains one of the major global concerns to be addressed and only global efforts could help in finding a solution. In terms of magnitude the economic impact of AMR is estimated to be comparable to that of climate global change in 2030. Although antibiotics continue to be essential to treat such infections, non-antibiotic therapies will play an important role in limiting the increase of antibiotic resistant microorganisms. Among non-antibiotic strategies, vaccines and therapeutic monoclonal antibodies (mAbs) play a strategic role. In this review, we will summarize the evolution and the mechanisms of antibiotic resistance, and the impact of AMR on life expectancy and economics.

Hepatitis B: Immunization and Impact on Natural History and Cancer Incidence

Enhancing host immunity by vaccination to prevent hepatitis B virus (HBV) infection remains the most important strategy for global control of hepatitis B. Currently, 187 countries have in place infant hepatitis B vaccination programs. Hepatitis B surface antigen prevalence has decreased to less than 1% in children after successful implementation of universal HBV vaccination in newborns. The incidence of primary liver cancer in children, adolescents, and young adults has drastically decreased to near zero in birth cohorts receiving hepatitis B vaccination. Elimination of chronic hepatitis B by 2030 is not a mission impossible.

Postnatal Zika virus infection of nonhuman primate infants born to mothers infected with homologous Brazilian Zika virus

Recent data in a nonhuman primate model showed that infants postnatally infected with Zika virus (ZIKV) were acutely susceptible to high viremia and neurological damage, suggesting the window of vulnerability extends beyond gestation. In this pilot study, we addressed the susceptibility of two infant rhesus macaques born healthy to dams infected with Zika virus during pregnancy. Passively acquired neutralizing antibody titers dropped below detection limits between 2 and 3 months of age, while binding antibodies remained detectable until viral infection at 5 months. Acute serum viremia was comparatively lower than adults infected with the same Brazilian isolate of ZIKV (n = 11 pregnant females, 4 males, and 4 non-pregnant females). Virus was never detected in cerebrospinal fluid nor in neural tissues at necropsy two weeks after infection. However, viral RNA was detected in lymph nodes, confirming some tissue dissemination. Though protection was not absolute and our study lacks an important comparison with postnatally infected infants born to naïve dams, our data suggest infants born healthy to infected mothers may harbor a modest but important level of protection from postnatally acquired ZIKV for several months after birth, an encouraging result given the potentially severe infection outcomes of this population.

Long-term antibody persistence against hepatitis B in adolescents 14-15-years of age vaccinated with 4 doses of hexavalent DTPa-HBV-IPV/Hib vaccine in infancy

We evaluated antibody persistence against hepatitis B virus (HBV) in adolescents previously vaccinated with a hexavalent diphtheria-tetanus-acellular pertussis-HBV-inactivated poliovirus-Haemophilus influenzae type b conjugate vaccine (DTPa-HBV-IPV/Hib), as part of the national newborn immunization program in Germany. We also assessed the anamnestic response to a challenge dose of a monovalent HBV vaccine. In this phase 4, open-label, non-randomized study (NCT02798952), 302 adolescents aged 14-15 years, primed in their first 2 years of life with 4 DTPa-HBV-IPV/Hib doses, received one challenge dose of monovalent HBV vaccine. Blood samples were taken before and one month post-vaccination and used to determine antibody levels against hepatitis B surface antigen (HBs). Reactogenicity and safety were also assessed post-challenge dose. Pre-challenge dose, 53.7% of 268 participants included in the according-to-protocol cohort for immunogenicity had anti-HBs antibody concentrations ≥10 mIU/mL (seroprotection cut-off) and 16.8% had anti-HBs antibody concentrations ≥100 mIU/mL. One month post-challenge dose, 93.3% of adolescents had anti-HBs antibody concentrations ≥10 mIU/mL and 87.3% had antibody concentrations ≥100 mIU/mL. An anamnestic response was mounted in 92.5% of adolescents. Injection site pain (in 33.6% of participants) and fatigue (30.2%) were the most frequently reported solicited local and general symptoms, respectively. Six of the 55 unsolicited adverse events reported were considered vaccination-related. Two vaccination-unrelated serious adverse events were reported during the study. Long-term antibody persistence against hepatitis B was observed in 14-15 years old adolescents previously primed in infancy with DTPa-HBV-IPV/Hib. A challenge dose of monovalent HBV vaccine induced strong anamnestic response, with no safety concerns.

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.

Monitoring the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children: Protective anti-HBs levels and cellular immune responses

Vaccination against hepatitis B virus (HBV) is recommended worldwide. The aim of this study was to assess the efficacy of infant hepatitis B vaccination and revaccination in 0- to 8-year-old children in the context of protective anti-HBs levels and cellular immune responses. Using a random questionnaire survey, 1695 pre-school children were recruited as research subjects during January 2015 to June 2017. Blood samples were obtained to measure HBV serological markers as well as peripheral immunocytes. The children were divided into non-, low- and hyper- responsive groups (NR, LR, and HR) based on the vaccination efficacy. Additionally, the effect of revaccination on the NR group was evaluated at 1 month after completion of the vaccination course. Among a total of 1695 children, 1591 (93.86%) were infants who were followed while undergoing their primary course of hepatitis B vaccination at the 0-1-6 month schedule, and 1249 (79.30%) of them developed antibodies against HBsAg (anti-HBs) titers greater than 10 IU/L. The results of immunocyte studies indicated that the CD8⁺ T cells, CD4⁺CD45RO⁺ T cells, CD8⁺CD45RA⁺ T cells, and T follicular helper (Tfh) cells increased significantly in NR compared with HR. However, lymphocytes, CD4⁺ T cells, and CD4⁺CD45RA⁺ T cells in NR were lower than that in HR. 96 of the non-response cases showed seroprotection after revaccination among 103 cases. Therefore, most of the preschool children who received hepatitis B vaccine in infancy achieved significant seroprotection. Seroconversion rates of individuals revaccinated after initial vaccination failure were significantly higher than those after primary vaccination. Different vaccination efficacy groups showed significant changes in circulating immunocytes, which might be a factor affecting the recombinant HBV vaccine's immune effectiveness.