Safety and immunogenicity of IMVAMUNE smallpox vaccine using different strategies for a post event scenario

Introduction

Reintroduction of Variola major as an agent of bioterrorism remains a concern. A shortened dosing schedule of Bavarian Nordic's (BN) IMVAMUNE^® (modified vaccinia Ankara vaccine against smallpox) was compared to the currently recommended 0- and 28-day schedule for non-inferiority by evaluating the magnitude and kinetics of the immune responses.

Methods

Subjects were assigned to receive IMVAMUNE or placebo administered subcutaneously on Days 0 and 7, Days 0 and 28, or Day 0. Blood was collected for antibody and cell-mediated immune assays. Subjects were followed for safety for 12 months after last vaccination.

Results

The primary endpoint of this study was the geometric mean antibody titers (GMT) at 14 days post last vaccination. Of 208 subjects enrolled, 191 received vaccine (Group: 0 + 7, Group: 0 + 28 and Group: 0) and 17 received placebo. Moderate/severe systemic reactogenicity after any vaccination were reported by 31.1%, 25.4%, and 28.6% of the subjects for Group: 0 + 7, Group: 0 + 28, and Group: 0, respectively (Chi-square test, P = 0.77). Based on BN's Plaque Reduction Assay GMTs, Group: 0 + 7 was non-inferior to Group: 0 + 28 at Day 4, 180, and 365 after the second vaccination. On Day 14, Group: 0 + 7 and Group: 0 + 28 GMT were 10.8 (CI: 9.0, 12.9) and 30.2 (CI: 22.1, 41.1), respectively. Based on BN's Enzyme-linked immunosorbent assay, the proportion of subjects with positive titers for Group: 0 + 28 was significantly greater than that for Group: 0 + 7 after second vaccination at Days 4 and 180. By Day 14 after the second dose, the IFN-γ enzyme-linked immunosorbent spot (ELISPOT) responses were similar for Group: 0 + 28 and Group: 0 + 7.

Conclusion

Overall, a standard dose of IMVAMUNE (0.5 mL of 1 x 10⁸ TCID/mL) administered subcutaneously was safe and well tolerated. A second dose of IMVAMUNE at Day 28 compared to Day 7 provided greater antibody responses and the maximal number of responders. By Day 14 after the second dose, IFN-γ ELISPOT responses were similar for Group: 0 + 28 and Group: 0 + 7.     

Safety and immunogenicity of three different formulations of an adjuvanted varicella-zoster virus subunit candidate vaccine in older adults: A phase II,randomized, controlled study

Background

This study investigated the safety and immunogenicity of different formulations and schedules of a candidate subunit herpes zoster vaccine containing varicella-zoster virus glycoprotein E (gE) with or without the adjuvant system AS01_B.

Methods

In this phase II, single-blind, randomized, controlled study, adults aged ≥60 years (N = 714) received one dose of 100 μg gE/AS01_B, two doses, two months apart, of 25, 50, or 100 μg gE/AS01_B, or two doses of unadjuvanted 100 μg gE/saline. Frequencies of CD4⁺ T cells expressing ≥2 activation markers following induction with gE were measured by intracellular cytokine staining and serum anti-gE antibody concentrations by ELISA.

Results

Frequencies of gE-specific CD4⁺ T cells were >3-fold higher after two doses of all gE/AS01_B formulations than after one dose of 100 μg gE/AS01_B or two doses of 100 μg gE/saline. Frequencies were comparable after two doses of 25, 50, or 100 μg gE/AS01_B. Serum anti-gE antibody concentrations were comparable after two doses of 50 or 100 μg gE/AS01_B and higher than in the other groups. Immune responses persisted for at least 36 months. Reactogenicities of all gE/AS01_B formulations were similar but greater than with gE/saline.

Conclusions

The three formulations of gE/AS01_B were immunogenic and well tolerated in adults aged ≥60 years. Two vaccinations with gE/AS01_B induced higher immune responses than one and the dose of gE impacted humoral but not cellular immune responses (NCT00434577).     

Oral administration of an adenovirus vector encoding both an avian influenza A hemagglutinin and a TLR3 ligand induces antigen specific granzyme B and IFN-γ T cell responses in humans

Purpose

To test the safety and immunogenicity of an orally delivered avian influenza vaccine. The vaccine has a non-replicating adenovirus type 5 vector backbone which expresses hemagglutinin from avian influenza and a TLR3 ligand as an adjuvant.

Methods

Forty-two subjects were randomized into 3 groups dosed with either 1 × 10¹⁰, 1 × 10⁹, or 1 × 10⁸ IU of the vaccine administered in capsules. Twelve subjects were vaccinated with identical capsules containing placebo. A portion of the 1 × 10⁹ dose group were immunized a second time 4 weeks after the first immunization. The safety of the vaccine was assessed by measuring the frequency and severity of adverse events in placebo versus vaccine treated subjects. IFN-γ and granzyme B ELISpot assays were used to assess immunogenicity.

Results

The vaccine had a positive safety profile with no treatment emergent adverse events reported above grade 1, and with an adverse event frequency in the treated groups no greater than placebo. Antigen specific cytotoxic and IFN-γ responses were induced in a dose dependent manner and cytotoxic responses were boosted after a second vaccination.

Conclusion

This first in man clinical trial demonstrates that an orally delivered adenovirus vectored vaccine can induce immune responses to antigen with a favorable safety profile. Clinical Trial Registration number: NCT01335347.     

The immunological effects of oral polio vaccine provided with BCG vaccine at birth: A randomised trial

Background

Vaccines may have non-specific effects. An observational study from Guinea-Bissau suggested that oral polio vaccine at birth (OPV0) provided with Bacillus Calmette–Guérin (BCG) vaccine was associated with down-regulation of the immune response to BCG vaccine 6 weeks later. Based on the previous finding, we wanted to test our a priori hypothesis that OPV would dampen the immune response to BCG, and secondarily to test immune responses to other antigens.

Methods

The study was conducted at the Bandim Health Project in Guinea-Bissau in 2009–2010. Infants were randomised to OPV0 + BCG versus BCG alone at birth, and subsequently randomised to have a blood sample taken at 2, 4 or 6 weeks post-randomisation. Excreted levels of cytokines (IL-2, IL-5, IL-10, TNF-α and IFN-γ) were measured from whole blood in vitro stimulations with a panel of recall vaccine antigens (BCG, PPD, OPV), mitogen (PHA) or innate agonists (LPS, Pam3cys, PolyI:C). Additionally, we measured the local reaction to BCG, white blood cell distribution, C-reactive protein (CRP) and retinol-binding protein (RBP). Cytokine production was analysed as the prevalence ratios of responders above the median.

Results

Blood samples from 430 infants (209 OPV0 + BCG; 221 BCG alone) were analysed. There were no strong differences in effects 2, 4 and 6 weeks post-randomisation and subsequent analyses were performed on the pooled data. As hypothesised, receiving OPV0 + BCG versus BCG alone was associated with significantly lower prevalence of IFN-γ responses to PPD (prevalence ratio (PR): 0.84 (0.72–0.98)) and reduced IL-5 to PPD (PR: 0.78 (0.64–0.96)). No effects were observed for CPR, RBP, white blood cell distribution, or BCG scar prevalence.

Conclusion

The results corroborate that OPV attenuates the immune response to co-administered BCG at birth.     

Counseling and provision of long-acting reversible contraception in the US: National survey of nurse practitioners

Objective

Nurse practitioners (NPs) provide frontline care in women's health, including contraception, an essential preventive service. Their importance for contraceptive care will grow, with healthcare reforms focused on affordable primary care. This study assessed practice and training needs to prepare NPs to offer high-efficacy contraceptives — intrauterine devices (IUDs) and implants.

Method

A US nationally representative sample of nurse practitioners in primary care and women's health was surveyed in 2009 (response rate 69%, n = 586) to assess clinician knowledge and practices, guided by the CDC US Medical Eligibility Criteria for Contraceptive Use.

Results

Two-thirds of women's health NPs (66%) were trained in IUD insertions, compared to 12% of primary care NPs. Contraceptive counseling that routinely included IUDs was low overall (43%). Nurse practitioners used overly restrictive patient eligibility criteria, inconsistent with CDC guidelines. Insertion training (aOR = 2.4, 95%CI: 1.10 5.33) and knowledge of patient eligibility (aOR = 2.9, 95%CI: 1.91 4.32) were associated with IUD provision. Contraceptive implant provision was low: 42% of NPs in women's health and 10% in primary care. Half of NPs desired training in these methods.

Conclusion

Nurse practitioners have an increasingly important position in addressing high unintended pregnancy in the US, but require specific training in long-acting reversible contraceptives.     

Comparison of antibody and cell-mediated immune responses of foals and adult horses after vaccination with live Mycobacterium bovis BCG

Background

Equine neonates have reduced humoral and cell-mediated immune responses compared to adult horses after administration of killed vaccines. As a basis for this study, we hypothesized that newborn foals can mount strong immune responses after vaccination with live Mycobacterium bovis BCG.

Methods

Healthy 4-day-old foals (n = 7), 4-month-old foals (n = 7) and adult horses (n = 6) were vaccinated once with live M. bovis BCG. Age-matched animals (n = 5 per group) were used as unvaccinated controls. Relative vaccine-specific immunoglobulin concentrations and whole blood mRNA expression of IFN-γ, IL-4, and IL-10 were measured prior to and 2, 4, 6, and 8 weeks after vaccination. Eight weeks after vaccination, delayed type hypersensitivity (DTH) responses were assessed by measuring the increase in double skin thickness after intradermal injection of purified protein derivative.

Results

Both groups of foals and adult horses responded with a significant increase in vaccine-specific total IgG, IgGa, IgGc, IgG(T), and IgM concentrations. In contrast, only adult horses mounted significant IgGb responses. Vaccine-specific concentrations of total IgG and IgGa were significantly higher in adult horses than in 4-day-old foals whereas IgGc responses were significantly higher in 4-day-old foals than in the other two age groups. Adult horses had significantly higher basal IFN-γ and IL-4 mRNA expression than both groups of foals but vaccination with M. bovis BCG did not significantly increase expression of these cytokines, regardless of age group. Immunized horses had significantly higher DTH responses than age-matched unvaccinated controls. DTH responses were significantly greater in both groups of vaccinated foals than in vaccinated adult horses.

Conclusion

Despite a naïve immune system, newborn foals have the ability to mount robust antibody and cell-mediated immune responses to M. bovis BCG.     

Comparing the safety and immunogenicity of a candidate TB vaccine MVA85A administered by intramuscular and intradermal delivery

Background

New vaccines to prevent tuberculosis are urgently needed. MVA85A is a novel viral vector TB vaccine candidate designed to boost BCG-induced immunity when delivered intradermally. To date, intramuscular delivery has not been evaluated. Skin and muscle have distinct anatomical and immunological properties which could impact upon vaccine-mediated cellular immunity.

Methods

We conducted a randomised phase I trial comparing the safety and immunogenicity of 1 × 10⁸ pfu MVA85A delivered intramuscularly or intradermally to 24 healthy BCG-vaccinated adults.

Results

Intramuscular and intradermal MVA85A were well tolerated. Intradermally-vaccinated subjects experienced significantly more local adverse events than intramuscularly-vaccinated subjects, with no difference in systemic adverse events. Both routes generated strong and sustained Ag85A-specific IFNγ T cell responses and induced multifunctional CD4+ T cells. The frequencies of CD4+ T cells expressing chemokine receptors CCR4, CCR6, CCR7 and CXCR3 induced by vaccination was similar between routes.

Conclusions

In this phase I trial the intramuscular delivery of MVA85A was well tolerated and induced strong, durable cellular immune responses in healthy BCG vaccinated adults, comparable to intradermal delivery. These findings are important for TB vaccine development and are of relevance to HIV, malaria, influenza and other intracellular pathogens for which T cell-inducing MVA-based vaccine platforms are being evaluated.     

Identification of novel immunoreactive proteins of Streptococcus zooepidemicus with potential as vaccine components

Background

Streptococcus zooepidemicus is an important opportunistic pathogen of the equine respiratory and reproductive tracts. A normal tonsillar and mucosal commensal, it becomes invasive under conditions of stress such as virus infection, weaning, high temperature, prolonged transportation and failure of uterine involution. The aim of this study was to evaluate the vaccine potential of several surface exposed and secreted proteins of a novel mucoid clone of SzNC78 (ST-307) from an epizootic of equine respiratory disease.

Methods

An expression gene library of SzNC78 was probed with a pool of convalescent equine sera from a clonal epizootic of respiratory disease. Eleven proteins were selected and purified based on putative function, surface expression or secretion and possible importance as virulence factors. Three additional proteins (AhpC, GAPDH and enolase) were also included based on their putative virulence function. Groups of ICR mice were vaccinated subcutaneously with each recombinant antigen and QuilA and later challenged with SzNC78.

Results

SzM protected 100% mice (P < 0.01), followed by SzP and HylC which protected 90% mice (P = 0.01). MAP, SzMAC and ScpC each protected 63% (P < 0.05) mice. No control mouse survived challenge. SzM, MAP and ScpC in combination protected mice against a 10 fold higher dosage of SzNC78 than each antigen given separately. Protection against heterologous challenge (SzW60) was conferred by combinations of HylC + ScpC (60%; P = 0.05), followed by HylC + MAP (50%; P = 0.06) and ScpC + MAP (40%; P = 0.1). Serum antibody responses of horses recently recovered from Sz respiratory infection were highest against ScpC, MAP and SzP. A combination of SKC and Sz115 stimulated no protection against challenge with SzW60.

Conclusion

A subset of Sz proteins reactive with convalescent equine antibody have potential as components of experimental vaccines to aid in prevention of opportunistic Sz infections.     

The effect of timing of maternal tetanus,diphtheria, and acellular pertussis (Tdap) immunization during pregnancy on newborn pertussis antibody levels – A prospective study

Background

The Centers for Disease Control and Prevention recommend Tdap immunization during pregnancy, preferably at 27–36 weeks.

Aim

To ascertain whether there is a preferential period of maternal Tdap immunization during pregnancy that provides the highest concentration of pertussis-specific antibodies to the newborn.

Methods

This prospective study measured pertussis-specific antibodies in paired maternal-cord sera of women immunized with Tdap after the 20th week of their pregnancy (n = 61).

Results

The geometric mean concentrations (GMCs) of Immunoglobulin G (IgG) to pertussis toxin (PT) were higher in the newborns’ cord sera when women were immunized at 27–30⁺⁶ weeks (n = 21) compared with 31–36 weeks (n = 30) and >36 weeks (n = 7), 46.04 international units/milliliter (IU/mL) (95% CI, 24.29–87.30) vs. 8.69 IU/mL (95% CI, 3.66–20.63) and 21.12 IU/mL (95% CI, 7.93–56.22), p < 0.02, respectively. The umbilical cord GMCs of IgG to filamentous hemagglutinin (FHA) were higher in the newborns’ cord sera when women were immunized at 27–30⁺⁶ weeks compared with 31–36 weeks and >36 weeks, 225.86 IU/mL (95% CI, 182.34–279.76) vs. 178.31 IU/mL (95% CI, 134.59–237.03) and 138.03 IU/mL (95% CI, 97.61–195.16), p < 0.02, respectively.

Conclusions

Immunization of pregnant women with Tdap between 27–30⁺⁶ weeks was associated with the highest umbilical cord GMCs of IgG to PT and FHA compared with immunization beyond 31 weeks gestation. Further research should be conducted to reaffirm these finding in order to promote an optimal pertussis controlling policy.     

Delaying BCG vaccination from birth to 10 weeks of age may result in an enhanced memory CD4 T cell response

Background

In most tuberculosis (TB) endemic countries, bacillus Calmette–Guérin (BCG) is usually given around birth to prevent severe TB in infants. The neonatal immune system is immature. Our hypothesis was that delaying BCG vaccination from birth to 10 weeks of age would enhance the vaccine-induced immune response.

Methods

In a randomized clinical trial, BCG was administered intradermally either at birth (n = 25) or at 10 weeks of age (n = 21). Ten weeks after vaccination, and at 1 year of age, vaccine-specific CD4 and CD8 T cell responses were measured with a whole blood intracellular cytokine assay.

Results

Infants who received delayed BCG vaccination demonstrated higher frequencies of BCG-specific CD4 T cells, particularly polyfunctional T cells co-expressing IFN-γ, TNF-α and IL-2, and most strikingly at 1 year of age.

Conclusions

Delaying BCG vaccination from birth to 10 weeks of age enhances the quantitative and qualitative BCG-specific T cell response, when measured at 1 year of age.     

A recombinant adenovirus expressing immunodominant TB antigens can significantly enhance BCG-induced human immunity

Background

Despite the availability of Bacille Calmette Guérin (BCG) vaccines, Mycobacterium tuberculosis currently infects billions of people and millions die annually from tuberculosis (TB) disease. New TB vaccines are urgently needed.

Methods

We studied the ability of AERAS-402, a recombinant, replication-deficient adenovirus type 35 expressing the protective M. tuberculosis antigens Ag85A, Ag85B, and TB10.4, to boost BCG immunity in an area of low TB endemicity.

Results

In volunteers primed with BCG 3 or 6 months prior to AERAS-402 boosting, significant CD4⁺ and CD8⁺ T cell responses were induced. Ag85-specific responses were more strongly boosted than TB10.4-specific responses. Frequencies of TB-specific CD8⁺ T cells reached > 50 fold higher than pre-AERAS boosting levels, remarkably higher than reported in any previous human TB vaccine trial. Multiparameter flow cytometric assays demonstrated that AERAS-402-boosted CD4⁺ and CD8⁺ T cells were multifunctional, producing multiple cytokines and other immune effector molecules. Furthermore, boosted T cells displayed lymphoproliferative capacity, and tetramer analyses confirmed that antigen-specific CD8⁺ T cells were induced. BCG and AERAS-402 vaccinations given 3 and 6 months apart appeared equivalent.

Conclusions

Our results indicate that AERAS-402 is a promising TB vaccine candidate that can significantly enhance both CD4⁺ and CD8⁺ TB-specific T cell responses after BCG priming.ClinicalTrials.gov Identifier: NCT01378312.     

Oral vaccination against HPV E7 for treatment of cervical intraepithelial neoplasia grade 3 (CIN3) elicits E7-specific mucosal immunity in the cervix of CIN3 patients

Background

Cervical intraepithelial neoplasia grade 3 (CIN3) is a mucosal precancerous lesion caused by high-risk human papillomavirus (HPV). Induction of immunological clearance of CIN3 by targeting HPV antigens is a promising strategy for CIN3 therapy. No successful HPV therapeutic vaccine has been developed.

Methods

We evaluated the safety and clinical efficacy of an attenuated Lactobacillus casei expressing modified full-length HPV16 E7 protein in patients with HPV16-associated CIN3. Ten patients were vaccinated orally during dose optimization studies (1, 2, 4, or 6 capsules/day) at weeks 1, 2, 4, and 8 (Step 1). Seven additional participants were only tested using the optimized vaccine formulation (Step 2), giving a total of 10 patients who received optimized vaccination. Cervical lymphocytes (CxLs) and peripheral blood mononuclear cells (PBMCs) were collected and E7 specific interferon-γ-producing cells were counted (E7 cell-mediated immune responses: E7-CMI) by ELISPOT assay. All patients were re-evaluated 9 weeks after initial vaccine exposure using cytology and biopsy to assess pathological efficacy.

Results

No patient experienced an adverse event. E7-CMI in both CxLs and PBMCs was negligible at baseline. All patients using 4–6 capsules/day showed increased E7-CMI in CxLs, whereas patients using 1–2 capsules/day did not. No patient demonstrated an increase in E7-CMI in their PBMCs. In comparison between patients of cohorts, E7-CMI at week 9 (9 wk) in patients on 4 capsules/day was significantly higher than those in patients on 1, 2, or 6 capsules/day. Most patients (70%) taking the optimized dose experienced a pathological down-grade to CIN2 at week 9 of treatment. E7-CMI in CxLs correlated directly with the pathological down-grade.

Conclusions

Oral administration of an E7-expressing Lactobacillus-based vaccine can elicit E7-specific mucosal immunity in the uterine cervical lesions. We are the first to report a correlation between mucosal E7-CMI in the cervix and clinical response after immunotherapy in human mucosal neoplasia.     

Safety and immunogenicity of the recombinant BCG vaccine VPM1002 in a phase 1 open-label randomized clinical trial

Background

Current vaccination using Mycobacterium bovis bacillus Calmette-Guérin (BCG), fails to prevent pulmonary tuberculosis (TB). New vaccination strategies are essential for reducing the global incidence of TB. We assessed the safety and immunogenicity of VPM1002, a recombinant BCG vaccine candidate. EudraCT (2007-002789-37) and ClinicalTrials.gov (NCT00749034).

Methods

Healthy volunteers were enrolled in a phase 1 open-label, dose escalation randomized clinical trial, and received one intradermal dose of VPM1002 (Mycobacterium bovis BCG ΔureC::hly Hm^R) or BCG. Immunogenicity was assessed by interferon-gamma (IFN-γ) production, cellular immune response markers by flow cytometry and serum antibodies against mycobacterial antigens.

Results

Eighty volunteers were randomized into two groups according to previous BCG vaccination and mycobacterial exposure (BCG-naïve, n = 40 and BCG-immune, n = 40). In each group, 30 individuals were vaccinated with VPM1002 (randomized to three escalating doses) and 10 with BCG. VPM1002 was safe and stimulated IFN-γ-producing and multifunctional T cells, as well as antibody-producing B cells in BCG-naïve and BCG-immune individuals.

Conclusions

VPM1002 was safe and immunogenic for B-cell and T-cell responses and hence will be brought forward through the clinical trial pipeline.     

Tests de dépistage rapides du VIH dans des consultations de dépistage anonyme et gratuit aux Antilles

Objective

Late screening for HIV is frequent in people living in the French West Indies. Rapid tests (RT) create new opportunities to improve screening for HIV. We evaluated the feasibility and acceptability of RT among users of free and anonymous screening consultations in Fort-de-France and Saint-Martin.

Methods

After confirming its reliability on more than 20,000 samples, a RT (Determine HIV-1 + 2^®) was offered on site to all testers in addition to the classic tests.

Results

From October 2007 to May 2008, 373 RT were performed, four were confirmed positive. Results of RT were returned to 99.4% of testers versus 89.4% of persons who underwent additional classic tests. The rate for unclaimed classic tests results was higher for the latter than for persons who had only RT: 22.2% versus 10.6%.

Conclusions

Results show that RT improves the proportion of people who are informed of their results. Nevertheless, efforts must be made to persuade patients to come back for results of the standard tests to be informed of a potential sexually transmitted infection or an acute HIV infection.     

Human vaginal histology in long-term users of the injectable contraceptive depot-medroxyprogesterone acetate

Objectives

Apparently, depot-medroxyprogesterone acetate (DMPA) increases a woman's risk of acquiring HIV. The objective of this study was to test whether the vaginal mucosal thickness and Langerhans cell counts were significantly different in long-term DMPA users compared with women users of an intrauterine device (IUD) who had never used DMPA.

Study design

Cross-sectional study. Twenty-three DMPA users were matched with 23 nonusers controlled for age, body mass index (BMI; kg/m²), and duration of contraceptive use. Four groups of women were evaluated according to the duration of DMPA use: > 1, < 5; ≥ 5, < 10; ≥ 10, < 15 or ≥ 15 years. Estradiol (E₂) levels were compared between the two groups. Histologic sections of vaginal mucosal biopsies were evaluated to measure the mean epithelial thickness and S100 immunostained sections were used to count the number of Langerhans cells/mm.

Results

Mean (± S.D.) E₂ levels were significantly lower in DMPA users (39.4±26.6 pg/mL) compared with nonusers (102.6±60.3 pg/mL) despite similar ages (42.3±7.4 and 42.4±7.4 years, respectively). Mean (± S.D.) vaginal thickness was 232.6±108.1 and 229.7±112.9 in DMPA users and nonusers, respectively. There were no differences in vaginal thickness or Langerhans cell count/mm between users and nonusers even after controlling for DMPA duration of use.

Conclusions

Vaginal epithelial thinning or Langerhans cell count was not different between long-term DMPA users and copper-IUD users who had never used DMPA.

Implications

No differences were found in vaginal epithelial thickness or in Langerhans cell count between long-term users of the injectable contraceptive DMPA and nonusers.     

Immune response after one or two doses of pandemic influenza A (H1N1) monovalent,AS03-adjuvanted vaccine in HIV infected adults

Introduction

Continued research is needed to evaluate and improve the immunogenicity of influenza vaccines in HIV infected patients. We aimed to determine the antibody responses after one or two doses of the AS03-adjuvanted pandemic influenza A (H1N1) vaccine in HIV infected patients.

Method

Following the influenza season 2009/2010, 219 HIV infected patients were included and divided into three groups depending on whether they received none (n = 60), one (n = 31) or two (n = 128) doses of pandemic influenza A (H1N1) vaccine. At inclusion, antibody titers for all patients were analyzed and compared to pre-pandemic antibody titers analyzed from serum samples in a local storage facility.

Results

4–9 months after a single immunization, we found a seroprotection rate of 77.4% and seroconversion rate of 67.7%. After two immunizations the rates increased significantly to seroprotection rate of 97.7% and seroconversion rate of 86.7%.

Conclusion

A single dose of AS03-adjuvanted pandemic influenza A (H1N1) vaccine created an adequate immune response in HIV infected patients lasting as long as 4–9 months. Two doses improved the immunogenicity further.     

High expression of MAGE-A4 and MHC class I antigens in tumor cells and induction of MAGE-A4 immune responses are prognostic markers of CHP-MAGE-A4 cancer vaccine

Purpose

We conducted a cancer vaccine clinical trial with MAGE-A4 protein. Safety, clinical response, and antigen-specific immune responses were analyzed and the prognostic factors by vaccination were investigated.

Experimental design

Twenty patients with advanced esophageal, stomach or lung cancer were administered MAGE-A4 vaccine containing 300 μg protein subcutaneously once every 2 weeks in six doses. Primary endpoints of this study were safety and MAGE-A4 immune responses.

Results

The vaccine was well tolerated. Fifteen of 20 patients completed one cycle of vaccination and two patients showed SD. A MAGE-A4-specific humoral immune response was observed in four patients who had high expression of MAGE-A4 and MHC class I on tumor cells. These four patients showed significantly longer overall survival than patients without an antibody response after vaccination (p = 0.009). Patients with tumor cells expressing high MAGE-A4 or MHC class I antigen showed significantly longer overall survival than those with low expression. Induction of CD4 and CD8T cell responses was observed in three and six patients, respectively, and patients with induction of MAGE-A4-specific IFNγ-producing CD8T cells, but not CD4T cells, lived longer than those without induction.

Conclusions

The CHP-MAGE-A4 vaccine was safe. Expression of MAGE-A4 and MHC class I in tumor tissue and the induction of a MAGE-A4-specific immune response after vaccination would be feasible prognostic markers for patients vaccinated with MAGE-A4.     

Decreased immune response to pneumococcal conjugate vaccine after 23-valent pneumococcal polysaccharide vaccine in children

Background

Pneumococcal polysaccharide vaccine (PPV) is used in children at high risk of IPD. PPV is generally not considered to induce immunologic memory, whereas pneumococcal conjugate vaccines (PCVs) elicit protective antibody responses in infants and induce immunologic memory. Little is known about the characteristics of immune responses to PCV in children who previously received PCV and PPV in series.

Objective

To characterize immune responses to 13-valent pneumococcal CRM₁₉₇ conjugate vaccine (PCV13; serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) in children vaccinated in infancy with 9-valent pneumococcal–meningococcal C-CRM₁₉₇ conjugate combination vaccine (PCV9-MnCC), followed by a toddler dose of PCV9-MnCC or 23-valent pneumococcal polysaccharide vaccine (PPV23).

Methods

Children (n = 89) who received PCV9-MnCC in infancy and PPV23 or PCV9-MnCC at age 12 months in a previous (2002–2003) study were vaccinated at age 7.5 years with PCV13; groups PPV23/PCV13 (n = 50) and PCV9/PCV13 (n = 39). Immunoglobulin (Ig)G antibodies, avidity, and opsonophagocytic activity (OPA) were measured before and at 1 and 4 weeks postvaccination.

Results

One week postvaccination, IgG levels increased significantly for all serotypes in both groups, and >97% of vaccinees achieved IgG ≥0.35 μg/ml 4 weeks after PCV13 vaccination. The PCV9/PCV13 group had higher IgG responses compared with the PPV23/PCV13 group. The upper limits of the 95% confidence intervals of the PPV23/PCV13:PCV9/PCV13 IgG geometric mean concentration ratios were <1.0 for serotypes 1, 4, 5, 9V, 18C, and 23F at 1 week. OPA and avidity results supported these findings.

Conclusions

PPV23 vaccination of toddlers may compromise subsequent responses to pneumococcal conjugate vaccines. The clinical relevance of this finding is unclear.     

Associations between race,sex and immune response variations to rubella vaccination in two independent cohorts

Introduction

Immune response variations after vaccination are influenced by host genetic factors and demographic variables, such as race, ethnicity and sex. The latter have not been systematically studied in regard to live rubella vaccine, but are of interest for developing next generation vaccines for diverse populations, for predicting immune responses after vaccination, and for better understanding the variables that impact immune response.

Methods

We assessed associations between demographic variables, including race, ethnicity and sex, and rubella-specific neutralizing antibody levels and secreted cytokines (IFNγ, IL-6) in two independent cohorts (1994 subjects), using linear and linear mixed models approaches, and genetically defined racial and ethnic categorizations.

Results

Our replicated findings in two independent, large, racially diverse cohorts indicate that individuals of African descent have significantly higher rubella-specific neutralizing antibody levels compared to individuals of European descent and/or Hispanic ethnicity (p < 0.001).

Conclusion

Our study provides consistent evidence for racial/ethnic differences in humoral immune response following rubella vaccination.     

Microstructured liposome subunit vaccines reduce lung inflammation and bacterial load after Mycobacterium tuberculosis infection

Background

Tuberculosis is a disease affecting millions of people throughout the world. One of the main problems in controlling the disease is the low efficacy of the Bacillus Calmette–Guérin (BCG) vaccine in protecting young adults. The development of new vaccines that induce a long-lasting immune response or that stimulate the immunity induced by BCG may improve the control of tuberculosis.

Methods

The use of microstructured liposomes containing HspX, with or without MPL or CpG DNA adjuvants, as vaccines for tuberculosis was evaluated. The HspX-specific humoral and cellular immune responses to the different vaccine formulations were compared.

Results

All vaccines containing liposome microparticles and HspX were immunogenic. Vaccines formulated with CpG DNA and HspX induced the strongest humoral and cellular immune responses, mainly by inducing interferon-γ and tumor necrosis factor-α expression by both CD4⁺ and CD8⁺ T cells. HspX and MPL mainly induced CD8⁺ T-cell activation and specific humoral responses. When evaluated the protective efficacy of the formulations against Mycobacterium tuberculosis challenge, the microstructured liposome containing L-HspX and L-HspX-CPG DNA reduced both lung inflammatory lesions and the bacterial load.

Conclusion

We have thus demonstrated, for the first time, the use of microstructured liposomes as an adjuvant and delivery system for a vaccine formulation against tuberculosis.