Immunogenicity and safety assessment of the Cuban recombinant hepatitis B vaccine in healthy adults

The protective role of maternal genetic immunization on maternal-fetal health and welfare

Pregnancy is a critical period associated with alterations in physiologic, biologic, and immunologic processes, which can affect maternal-fetal health through development of several infectious diseases. At birth, neonates have an immature immune system that makes them more susceptible to severe viral infections and diseases. For this reason, different maternal nutritional and immunization interventions have been used to improve the immune and health status of the mother and her neonate through passive immunity. Here, we reviewed the protective role of maternal immunization with different types of vaccines, especially genetic vaccines, during pregnancy in maternal-fetal health, immune response, colostrum quality, immune response, and anti-oxidative status. For this purpose, we have used different scientific databases (PubMed and Google Scholar) and other official web pages. We customized the search period range from the year 2000 to 2023 using the key words "maternal immunization" OR "gestation period/pregnancy" OR "genetic vaccination" OR "maternal-fetal health" OR "micronutrients" OR "neonatal immunity" "oxidative stress" OR "colostrum quality". The evidence demonstrated that inactivated or killed vaccines produced significant immune protection in the mother and fetus. Furthermore, most recent studies have suggested that the use of genetic vaccines (mRNA and DNA) during pregnancy is efficient at triggering the immune response in mother and neonate without the risk of undesired pregnancy outcomes. However, factors such as maternal redox balance, nutritional status, and the timing of immunization play essential roles in regulating immune response inflammatory status, antioxidant capacity, and the welfare of both the pregnant mother and her newborn.

Body Mass Index and Antibody Persistence after Measles, Mumps, Rubella and Hepatitis B Vaccinations

Overweight and obesity may cause a reduced response to vaccination. The purpose of the present research was to study the relationship between current body mass index (BMI) and antibody persistence after vaccination against measles, mumps, and rubella (MMR) and hepatitis B virus (HBV) given during childhood, as per the current vaccination schedule. The study was conducted on 2185 students at the School of Medicine, University of Padua, Italy. The mean age of the participants was 20.3 years. After adjusting for sex, age at first dose of vaccine administered, age at last dose, and age at study enrollment, no significant association was found between lack of serologic protection and BMI for either the HBV vaccine or each component of the MMR vaccine. For the first time, the absence of this relationship was demonstrated for the MMR vaccine. Given the evidence currently available, further research on BMI and vaccines in general remains desirable.

Obesity: A comorbidity-acquired immunodeficiency syndrome (CAIDS)

Accumulating data emphasize a strong link between obesity and the severity of coronavirus disease-2019 (COVID-19), including mortality. Obesity interferes with several components of the immune system including lymphoid tissue's integrity, leukocytes' development and function, complement system's activation, and the coordination of innate and adaptive immune responses. Overall, obesity results in a less efficient immune response to infectious agents. Severe acute respiratory syndrome coronavirus 2 exploits this weakened immune system in people with obesity to precipitate COVID-19, and in some cases death. It is therefore the author's recommendation that obesity should be viewed as another form of acquired immunodeficiency syndrome and be treated with the appropriate seriousness. Unlike the previously described acquired immunodeficiency syndrome (AIDS) that is caused by the Human Immunodeficiency Virus (HIV), obesity is a comorbidity-acquired immunodeficiency syndrome. People with AIDS do not die from HIV, but may die from opportunistic pathogens such as Mycobacterium tuberculosis. However, AIDS is ascribed its due importance in the course of deterioration of the patient. Similarly, obesity should be acknowledged further as a risk factor for mortality from COVID-19. Obesity is a modifiable condition and even in people with a strong genetic predisposition, lifestyle modifications can reverse obesity, and even moderate weight loss can improve the inflammatory milieu. Strong public health actions are warranted to promote lifestyle measures to reduce the burden from overweight and obesity that currently affect more than one-third of the global population, with projections alarming this may reach 55-80% within the next thirty years.

Safety, tolerability, and immunogenicity of a SARS-CoV-2 recombinant spike RBD protein vaccine: A randomised, double-blind, placebo-controlled, phase 1-2 clinical trial (ABDALA Study)

BACKGROUND

Multiple vaccine candidates against COVID-19 are currently being evaluated. We evaluate the safety and immunogenicity protein of a novel SARS-CoV-2 virus receptor-binding domain (RBD) vaccine.

METHODS

A phase 1-2, randomised, double-blind, placebo-controlled trial was carried out in "Saturnino Lora" Hospital, Santiago de Cuba, Cuba. Subjects (healthy or those with controlled chronic diseases) aged between 19 and 80 years, who gave written informed consent were eligible. Subjects were randomly assigned (1:1:1, in blocks) to three groups: placebo, 25 µg and 50 µg RBD vaccine (Abdala). The product was administered intramuscularly, 0·5 mL in the deltoid region. During the first phase, two immunization schedules were studied: 0-14-28 days (short) and 0-28-56 days (long). In phase 2, only the short schedule was evaluated. The organoleptic characteristics and presentations of vaccine and placebo were identical. All participants (subjects, clinical researchers, statisticians, laboratory technicians, and monitors) remained masked during the study period. The main endpoints were safety and the proportion of subjects with seroconversion of anti-RBD IgG antibodies, analysed by intention to treat and per protocol, respectively. The trial is registered with the Cuban Public Registry of Clinical Trials, RPCEC00000346.

FINDINGS

Between Dec 7, 2020, and Feb 9, 2021, 792 subjects were included; 132 (66 in each vaccination schedule, divided into 22 for each group) in phase 1, and 660 (220 in each group plus 66 from the short scheme of phase 1) in phase 2. The product was well tolerated. No severe adverse events were reported. During phase 1, the incidence of adverse events in the 25 µg, 50 µg, and placebo arms for the short schedule were 6/22 (27·3%), 6/22 (27·3%), 3/22 (13·6%), respectively, and for the long schedule were 8/22 (36·4%), 9/22 (40·9%), 4/22 (18·2%), respectively. In phase 2, adverse reactions were reported by 53/242 (21·9%), 75/242 (31·0%) and 41/242 (16·9%) participants in the 25 µg, 50 µg, and placebo group, respectively. Adverse reactions were minimal, mostly mild, and from the injection site, which resolved in the first 24-48 hours. In phase 1, seroconversion at day 56 was seen in 95·2% of the participants (20/21) in the 50 μg group, 81% (17/21) in the 25 μg group, and none in the placebo group (0/22). For the long schedule, seroconversion at day 70 was seen in 100% of the participants (21/21) in the 50 μg group, 94·7% (18/19) in the 25 μg group, and none in the placebo group (0/22). In phase 2, seroconversion of anti-RBD IgG antibodies at day 56 was seen in 89·2% of the participants in the 50 μg group (214/240; 95% CI 84·5-92·82), 77·7% in the 25 μg group (185/238; 72·0-82·9) and 4·6% in the placebo group (11/239; 2·3-8·1). Compared with the placebo arm, the differences in the proportion of participants with seroconversion were 73·1% (95% CI 66·8-79·5) and 84·6% (79·4-89·7) in the 25 μg and 50 μg groups, respectively. The seroconversion rate in the 50 μg group was significantly higher than in the 25 μg group (p=0·0012).

INTERPRETATION

The Abdala vaccine was safe, well tolerated, and induced humoral immune responses against SARS-CoV-2. These results, in the context of the emergency COVID-19 pandemic, support the 50 μg dose, applied in a 0-14-28 days schedule, for further clinical trials to confirm vaccine efficacy.

FUNDING

Centre for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.

Two-year immune effect differences between the 0-1-2-month and 0-1-6-month HBV vaccination schedule in adults

Background

The short-term 0–1–2-month hepatitis B virus (HBV) vaccination schedule was previously implemented in the adult population; however, its long-term immune effect remains unclear. The present study aimed to investigate (1) the 2-month and 2-year immune effects of HBV vaccination and (2) the compliance rate between the 0–1–2-month and 0–1–6-month vaccination schedules in adults.

Method

A total of 1281 subjects tested for hepatitis B surface antigen HBsAg(−) and hepatitis B surface antibody (anti-HBs)(−) were recruited. Participants from two distant counties were inoculated with the hepatitis B yeast vaccine at 10 µg per dose, with vaccination schedules of 0, 1, and 2 months (n = 606) and 0, 1, and 6 months (n = 675); sequential follow-up was performed at 2 months and 2 years after the 3rd injection.

Results

There were no significant differences in the anti-HBs seroconversion rates between the those in the 0–1–2-month and 0–1–6-month vaccination schedule groups at 2 months (91.96% vs. 89.42%, p = 0.229) and 2 years (81.06% vs. 77.14%, p = 0.217). The quantitative anti-HBs level in those in the 0–1–2-month vaccination schedule group was not different from that in those in the 0–1–6-month vaccination schedule group at 2 months (anti-HBs₁) (342.12 ± 378.42 mIU/ml vs. 392.38 ± 391.96 mIU/ml, p = 0.062), but it was higher at 2 years (anti-HBs₂) (198.37 ± 286.44 mIU/ml vs. 155.65 ± 271.73 mIU/ml, p = 0.048). According to the subgroup analysis, the 0–1–2-month vaccination schedule induced better maintenance (p = 0.041) and longer reinforcement (p = 0.019) than the 0–1–6 vaccination schedule. The 0–1–2-month vaccination schedule group also had a higher 3rd injection completion rate (89.49% vs. 84.49%, p = 0.010).

Conclusion

The 0–1–2-month vaccination schedule was associated with a similar short-term immune effect and might induce better long-term immune memory and a higher completion rate in the adult population.

Trial registration None

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07151-6.

Immunogenicity and safety of hepatitis B vaccination in patients with type 2 diabetes in China: An open-label randomized controlled trial

OBJECTIVE

Hepatitis B virus (HBV) infection remains a global public health challenge. Patients with diabetes are at greater risk of HBV infection than healthy people. The immunogenicity and safety of two major hepatitis B vaccines were evaluated in Chinese patients with diabetes.

METHODS

In this phase IV, open-label, randomized, controlled study, participants with diabetes were randomly recruited from 6 townshiphealthcenters in Gansu Province and received either a 3-dose Saccharomyces cerevisiae recombinant hepatitis B vaccine (Group D20SC 0-1-6, n = 113) or a 3-dose Chinese hamster ovary cell (CHO) recombinant hepatitis B vaccine (Group D20CHO 0-1-6, n = 119). Healthy control groups were randomly recruited from the same 6 health centers and received 3 doses of the saccharomyces cerevisiae recombinant hepatitis B vaccine (Group ND20SC 0-1-6, n = 77). Immunogenicity, including seroconversion rate and geometric mean concentration (GMC) at 1 month after three doses of vaccination, and safety were assessed. The seroconversion rate was defined as the concentration of HBsAb ≥ 10 mIU/mL.

RESULTS

The seroconversion rates of Group D20SC 0-1-6, Group D20CHO 0-1-6 and Group ND20SC 0-1-6 were 89.6%, 91.4% and 97.1%, respectively, in the per-protocol analysis, and these differences were not statistically significant. The antibody concentration in Group D20SC 0-1-6 (GMC = 601 mIU/mL) was lower than that of the healthy control group (GMC = 1465 mIU/mL), but no significant difference was found in the GMC between the Group D20CHO 0-1-6 (GMC = 778 mIU/mL) and Group D20SC 0-1-6. Adverse events (AEs) were comparable between groups, and no serious AEs were found in these three groups.

CONCLUSIONS

The Saccharomyces cerevisiae recombinant and CHO recombinant hepatitis B vaccines in China can induce good immunogenicity in a diabetic population, although the antibody concentration may be lower, indicating the feasibility of vaccinating a large number of diabetic patients in China with these vaccines.

Risk factors of the efficacy of hepatitis B vaccine in health-care workers

Background

Conventional hepatitis B virus vaccination fails to achieve efficient protection in about 5%-10% of the world population. Different factors influence the immunogenicity of hepatitis B vaccine. This study aimed to evaluate these factors in health-care workers.

Materials and Methods

This was a descriptive study which was implemented among 140 of medical and dental staff working as health-care workers who were low responder after vaccination entered the study.

Results

Age (>40 years), weight (body mass index >25), immunodeficiency diseases, (primary immune deficiency and immunosuppressant drugs), diabetes mellitus, and smoking were the important factors.

Conclusion

In the high-risk group of hepatitis B disease, the risk factors of immunogenicity must be evaluated at vaccination and check titers of antibody after vaccination.

Factors That Influence the Immune Response to Vaccination

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

Influences of obesity on the immunogenicity of Hepatitis B vaccine

OBJECTIVE

Hepatitis B vaccine is regarded as the most effective method for the prevention of hepatitis B virus (HBV) infection. However, several factors such as age, body mass index and immunocompetent state have been reported to be associated with reduced immunization responses. The present commentary was aimed to discuss the influences of obesity on the immunogenicity of hepatitis B vaccines.

DATA SOURCES

Available peer-reviewed literatures, practice guidelines, and statistics published on hepatitis B vaccine in obesity between 1973 and 2015.

CONCLUSIONS

Obesity was significantly associated with non-response to hepatitis B vaccine immunization. The risk of nonresponsiveness of hepatitis B vaccine among obese people increased with BMI. Moreover, the obesity might lead to an increased risk of HBV vaccine-escape mutations. The mechanism responsible for decreased immunization responses in obesity included leptin-induced systemic and B cell intrinsic inflammation, impaired T cell responses and lymphocyte division and proliferation. Therefore, more studies should be performed to analyze the influences of obesity on the immunogenicity of hepatitis B vaccines to improve the immunoprotecive effect of hepatitis B vaccines in future.

Suitable hepatitis B vaccine for adult immunization in China

The aim of this study was to evaluate, in adults, the immunogenicity of six hepatitis B vaccines with different doses or different manufacturers in the Chinese market and to provide evidence to support adult hepatitis B vaccination. Participants were randomly divided into six groups (I–VI). Six vaccines (4 at 10 μg/dose and 2 at 20 μg/dose) were administered intramuscularly to healthy adults at 0, 1 and 6 month intervals. All participants (16–50 years) who were negative for any hepatitis B virus serological markers were vaccinated. Anti-HBs levels were assessed 1 month and 1 year after the third vaccination. The anti-HBs seroconversion rate (anti-HBs >10mIU/ml) was 99.4 % (99.9 % for 10 μg dose groups and 97.9 % for 20 μg dose groups) 1 month after the third vaccination, and the anti-HBs seroreversion rate was 77.0 % (75.3 and 82.6 %) 1 year after the third vaccination (n = 1036). One month after completing the vaccinations, the seroconversion rates were not significantly different (100.0, 100.0, 99.6, 100.0 %) for the four 10 μg dose and two 20 μg dose groups (99.1, 96.9 %). One year after the third vaccination, the group II positive rate was significantly higher than the other three 10 μg dose groups, and the group VI positive rate was significantly higher than the other 20 μg dose group. Groups II and VI showed a significantly higher positive rate and anti-HBs geometric mean titer (GMT) than the other groups. The anti-HBs level declined with increasing age, and the seroreversion rate and GMT decreased over time. All six vaccines had high anti-HBs seroconversion rates and good immunization effects. The 10 μg dose vaccine (Dalian High-Tech) and the 20 μg dose vaccine (GlaxoSmithKline) are recommended for adults.

Comparing Anti-hepatitis B Antibody Level in Iranian Obese or Overweight with Non-obese Cases

BACKGROUND

There is a controversy about the relation between anti-hepatitis B (anti-HBs) antibody level and obesity. We designed this study to compare the vaccine efficacy in obese/overweight and non-obese cases.

METHODS

In this cross-sectional study, 242 obese/overweight and 85 non-obese individuals were participated. Cases were selected from a referral clinic for obesity and a referral hepatology clinic, both in Tehran, Iran.

RESULTS

Obese cases had lower percentage of liver diseases (66.9% vs. 100%, P<0.001) but higher hepatitis B vaccination history (74.9% vs. 51.2%, P<0.001). Median±inter-quartile range of anti-HBs titer in obese cases was significantly lower than controls (48.5±194.5 vs. 100±557.6, P=0.012).

CONCLUSION

The level of anti-HBs surface antigen antibody's titer in obese cases without liver disease is lower than control group. Therefore, a suitable strategy is needed to overcome this problem, which can be the use of longer needles for vaccination.

Factors influencing immunologic response to hepatitis B vaccine in adults

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

Optimal vaccination program for healthy adults in China

There is still no suitable routine hepatitis B immunization strategy for adults in China. To establish an optimal vaccination schedule for healthy adults, we investigated various schedules in healthy adults. In this randomized 5143 healthy adults received 10 μg hepatitis B vaccine at 0, 1 and 3 months(group A), 0, 1 and 6 months(group B), or 0, 1 and 12 months(group C). Blood samples were collected after 1 month and 12 months after the third dose. The geometric mean titer (GMT), seroconversion rate (levels of anti-HBs ≥ 10 mIU/mL) and high response rate (levels of anti-HBs ≥ 100 mIU/mL) were assayed. In our study, 2438 healthy adults finished the full vaccination program and follow-up. The seroconversion/sero-protective rate of groups A-C at one and 12 month after administration of the third vaccine dose was 100%, 99.9% and 97.9% verse 64.9%, 75.7% and 79.0%, respectively. GMT for anti-HBs tested in group A to C within 1 or 12 month after the third vaccination was 213.16, 432.58 and 451.47 mIU/ml verse 22.07, 46.70 and 56.18 mIU/ml, respectively. There were significant differences of seroconversion/sero-protective rate and GMT among the 3 groups (p < 0.01). Given the high anti-HBs seroconversion rate and GMT in all 3 groups, a flexible schedule for Hepatitis B vaccine should be recommended to adults, but 0-1-12 schedule is a better choice.

Obesity: impact of infections and response to vaccines

Obesity is a common condition that has rapidly increased in both the industrialised and developing world in recent decades. Obese individuals show increased risk factors for severe infections and significant immune system dysregulation that may impair the immune response to vaccines. The main aim of this paper was to review the current knowledge regarding the association between obesity and the risk and outcome of infections as well as immune response to vaccines. The results showed that obesity is a highly complex clinical condition in which the functions of several organ and body systems, including the immune system, are modified. However, only a small minority of the biological mechanisms that lead to reduced host defences have been elucidated. Relevant efforts for future research should focus on obese children, as the available data on this population are scarce compared with the adult population. Even if most vaccines are given in the first months of life when obesity is rare, some vaccines require booster doses at preschool age, and other vaccines, such as the influenza vaccine, are recommended yearly in the obese population, but it is not known whether response to vaccines of obese patients is impaired. The reduced immune response of obese patients to vaccination can be deleterious not only for the patient but also for the community.

The weight of obesity on the human immune response to vaccination

Despite the high success of protection against several infectious diseases through effective vaccines, some sub-populations have been observed to respond poorly to vaccines, putting them at increased risk for vaccine-preventable diseases. In particular, the limited data concerning the effect of obesity on vaccine immunogenicity and efficacy suggests that obesity is a factor that increases the likelihood of a poor vaccine-induced immune response. Obesity occurs through the deposition of excess lipids into adipose tissue through the production of adipocytes, and is defined as a body-mass index (BMI) ≥ 30 kg/m(2). The immune system is adversely affected by obesity, and these "immune consequences" raise concern for the lack of vaccine-induced immunity in the obese patient requiring discussion of how this sub-population might be better protected.

Is obesity a risk factor for vaccine non-responsiveness?

Understanding the link between vaccine immunogenicity and efficacy is currently a major focus in HIV research. Consequently, recent developments in the HIV-1 vaccine field have led to a closer look at immune responses to known efficacious vaccines. We undertook a study to explore clinical predictors of vaccine efficacy following recombinant hepatitis B (rHBV) vaccination in a cohort of HIV-uninfected, hepatitis B virus naïve women living in a peri-urban setting in Cape Town. Our aim was to define host biological risk factors associated with lack of vaccine uptake. We found a significant association (p=0.009) between body mass index (BMI) and lack of vaccine-specific IgG titre (<10 mIU/mL). Obese individuals (BMI ≥ 30 kg/m(2)) were significantly more likely to be non-responders following 2 rHBV vaccine doses (Adjusted Odds Ratio of 8.75; p=0.043). There was no observed association between vaccine responses and age, method of contraception or time from vaccination to antibody measurement. These data suggest that obesity-associated factors interfere with vaccine immunogenicity and possible efficacy.

Conformational and thermal stability improvements for the large-scale production of yeast-derived rabbit hemorrhagic disease virus-like particles as multipurpose vaccine

Recombinant virus-like particles (VLP) antigenically similar to rabbit hemorrhagic disease virus (RHDV) were recently expressed at high levels inside Pichia pastoris cells. Based on the potential of RHDV VLP as platform for diverse vaccination purposes we undertook the design, development and scale-up of a production process. Conformational and stability issues were addressed to improve process control and optimization. Analyses on the structure, morphology and antigenicity of these multimers were carried out at different pH values during cell disruption and purification by size-exclusion chromatography. Process steps and environmental stresses in which aggregation or conformational instability can be detected were included. These analyses revealed higher stability and recoveries of properly assembled high-purity capsids at acidic and neutral pH in phosphate buffer. The use of stabilizers during long-term storage in solution showed that sucrose, sorbitol, trehalose and glycerol acted as useful aggregation-reducing agents. The VLP emulsified in an oil-based adjuvant were subjected to accelerated thermal stress treatments. None to slight variations were detected in the stability of formulations and in the structure of recovered capsids. A comprehensive analysis on scale-up strategies was accomplished and a nine steps large-scale production process was established. VLP produced after chromatographic separation protected rabbits against a lethal challenge. The minimum protective dose was identified. Stabilized particles were ultimately assayed as carriers of a foreign viral epitope from another pathogen affecting a larger animal species. For that purpose, a linear protective B-cell epitope from Classical Swine Fever Virus (CSFV) E2 envelope protein was chemically coupled to RHDV VLP. Conjugates were able to present the E2 peptide fragment for immune recognition and significantly enhanced the peptide-specific antibody response in vaccinated pigs. Overall these results allowed establishing improved conditions regarding conformational stability and recovery of these multimers for their production at large-scale and potential use on different animal species or humans.

Effect of GM-CSF in combination with hepatitis B vaccine on revacination of healthy adult non-responders

OBJECTIVE

To assess the immune effects and safety of using GM-CSF with the yeast-recombinant hepatitis B virus (HBV) vaccine for the re-vaccination of healthy adults who did not respond to a previous vaccination.

METHODS

Study participants included 1784 healthy adults and 100 individuals diagnosed as non-responders. These healthy non-responders were randomly assigned to one of the three treatment groups: Group A (34 individuals) was given 150 microg of granulocyte-macrophage colony stimulating factor (GM-CSF) the first day, then 20 microg of the vaccine; Group B (33 individuals) was given 40 microg of the vaccine only; and, group C (33 individuals) was injected with 20 microg of vaccine each time. All participants were injected three times, at time of study enrollment and one and six months later. Anti-HB surface antigen (HBs) antibody titers were tested before treatment and at one (T1), two (T2) and eight (T8) months post-first injection.

RESULTS

At T1, the rate of anti-HBs antibody(+) in groups A, B and C was 26.47%, 48.48% and 18.18%, respectively (p = .027). At T8, the seropositive rate of group A (64.71%) and group B (75.76%) was significantly higher than in group C (39.39%) (p = .011); the geometric mean of the antibody titer for groups A and B was higher than for group C (p = .0173). All three treatments were safe and well-tolerated.

CONCLUSIONS

Augmentation of the vaccine dose and co-administration of GM-CSF and the standard vaccine dose are effective for HBV vaccine non-responders. In fact, changing the vaccine dose had a better seropositive response than injecting the vaccine in combination with GM-CSF.

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

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

Sexual dimorphism of humoral immunity with human vaccines

It has been contended that limited data exist on sex-difference in immune response with vaccines in humans. However, a comprehensive search of the literature retrieved 97 studies with 14 vaccines influenza (7 studies), hepatitis A (15 studies), hepatitis B (50 studies), pnuemococcal polysaccaride (4 studies), diphtheria (4 studies), rubella (3 studies), measles (2 studies), yellow fever (3 studies), meningococcal A (1 study), meningococcal C (1 study), tetanus (1 study), brucella (1 study), Venezuelan equine encephalitis (1 study) and rabies (4 studies), with sex-difference in humoral (antibody) response. These differences are associated with sex-difference in the clinical efficacy of influenza, hepatitis A, hepatitis B, pneumococcal polysaccharide and diphtheria vaccines and significant adverse reactions with rubella, measles and yellow fever vaccines. The genesis of these differences is uncertain but not entirely related to gonadal hormones (differences are seen in pre-pubertal and post-menopausal subjects not on hormone replacement therapy) or female sex (males had greater serological response for pneumococcal, diphtheria, yellow fever, Venezuelan equine encephalitis and in some studies with rabies vaccine. As sex-difference in humoral immune response was seen with most vaccines which cover the spectrum of mechanisms by which infectious agents cause disease (mucosal replication, viral viraemia, bacterial bacteraemia, toxin production and neuronal invasion), it is mandatory that vaccine trialists recruit a representative sample of females and males to be able to assess sex-differences which may have clinical implications.