Alum-adjuvanted Vaccine Research Articles

Zika Virus Envelope Domain III Recombinant Protein Delivered With Saponin-Based Nanoadjuvant From Quillaja brasiliensis Enhances Anti-Zika Immune Responses, Including Neutralizing Antibodies and Splenocyte Proliferation.

Nanoadjuvants that combine immunostimulatory properties and delivery systems reportedly bestow major improvements on the efficacy of recombinant, protein-based vaccines. Among these, self-assembled micellar formulations named ISCOMs (immune stimulating complexes) show a great ability to trigger powerful immunological responses against infectious pathogens. Here, a nanoadjuvant preparation, based on saponins from Quillaja brasiliensis, was evaluated together with an experimental Zika virus (ZIKV) vaccine (IQB80-zEDIII) and compared to an equivalent vaccine with alum as the standard adjuvant. The preparations were administered to mice in two doses (on days zero and 14) and immune responses were evaluated on day 28 post-priming. Serum levels of anti-Zika virus IgG, IgG1, IgG2b, IgG2c, IgG3 were significantly increased by the nanoadjuvant vaccine, compared to the mice that received the alum-adjuvanted vaccine or the unadjuvanted vaccine. In addition, a robust production of neutralizing antibodies and in vitro splenocyte proliferative responses were observed in mice immunized with IQB80-zEDIII nanoformulated vaccine. Therefore, the IQB80-zEDIII recombinant preparation seems to be a suitable candidate vaccine for ZIKV. Overall, this study identified saponin-based delivery systems as an adequate adjuvant for recombinant ZIKV vaccines and has important implications for recombinant protein-based vaccine formulations against other flaviviruses and possibly enveloped viruses.

Evaluation Of Using Different Adjuvants Used For Preparation Of Staphylococcus Aureus Mastitis Vaccine On The Immune Response

Staphylococcus aureus (S. aureus) was the most prevalent bacteria recorded from clinical and subclinical mastitis. The main objective of the present work is to prepare and evaluate the effectiveness of locally prepared inactivated S. aureus vaccine using different adjuvants Montanide ISA-206, Montanide ISA-70 and alum hydroxide gel for detection of cellular and humeral immune responses. Seventy dairy heifers in the last trimester of gestation divided into (5) groups. Twenty pregnant cows in three groups (G1, G2, and G3) were inoculated intramuscularly with the prepared vaccines four weeks prior to calving then a booster dose at two weeks pre-expected calving. The animals in remaining groups (G4 and G5) were considered as control and safety test respectively. Serum samples from vaccinated and non-vaccinated cows were collected at the 1st and 2nd immunization then at 0, 1, 2, 3 months and (7, 10, 14) days post calving and vaccination and evaluated immunologically using ELISA and Lymphocyte transformation assay, respectively. The results revealed that a progressive increase of immune response in the vaccinated groups (G1 and G2) than that of the third and control groups. These results could be indicated the safety and effectiveness of the Montanide ISA-206, ISA-70 vaccines than alum adjuvant vaccine that reduce the incidence and severity of clinical cases of mastitis. Hence, further studies should be done to elucidate the possibility of field application.

1057. CpG-adjuvanted Hepatitis B vaccination improves seroprotection rates in Veterans with HIV

BackgroundHepatitis B virus (HBV) remains a global health issue, leading to complications including cirrhosis and hepatocellular carcinoma. Individuals co-infected with Human Immunodeficiency Virus (HIV) and HBV have increased liver-related morbidity and mortality compared to those with HBV mono-infection. Vaccination can effectively prevent HBV infection, but certain critical populations including people living with HIV (PLWH) are less likely to achieve seroprotection (antibody to hepatitis B surface antigen (HBsAb) titer ≥ 10 IU/mL) after vaccination; seroprotection rates (SPR) in PLWH range from 34 to 88% in clinical trials, with improved SPR in those with immunologic reconstitution and viral suppression. With improved immunologic status, SPR have dramatically improved in our Veteran Infectious Disease clinic population. However, a subset of patients remain HBV vaccine nonresponders despite re-vaccination attempts, perhaps due to intrinsic immunologic anergy. We hypothesized that Veterans with HIV who were nonresponders to prior HBV vaccines may respond to a more immunogenic vaccine. Heplisav-B is a 2-dose series, with improved SPR in other classically difficult to vaccinate groups (including the elderly and those with diabetes), but has not yet been studied in individuals with HIV.MethodsHBV vaccine nonresponders who had previously been vaccinated and boosted with median 3 and up to 8 doses of alum-adjuvanted HBV vaccines were re-vaccinated with Heplisav-B. HBsAb titers were assessed at days 0, 30, and 60 to follow vaccine responses.ResultsParticipants had a median age of 65 (range 44 to 83) and were virologically suppressed on antiretroviral therapy. Enrollment and vaccination was interrupted by the COVID-10 pandemic, but 8 of 10 (80%) enrolled participants had seroprotective titers at day 60, with 6 having titers > 1000 IU/mL. Of the 8 additional participants who had available serologies after the first dose, all were seroprotected, and 3 had titers > 1000 IU/mL.16 of 18 (89%) participants achieved seroprotection with Heplisav-B.ConclusionHeplisav-B is immunogenic in persons with HIV and should be a reasonable option for HBV vaccination of PLWH who are previous nonresponders.Disclosures Shyam Kottilil, MD PhD, Arbutus Pharmaceuticals (Grant/Research Support)Gilead Sciences (Grant/Research Support)Merck Inc (Grant/Research Support, Advisor or Review Panel member)

The Potency of an Anti-MERS Coronavirus Subunit Vaccine Depends on a Unique Combinatorial Adjuvant Formulation.

Vaccination is one of the most successful strategies to prevent human infectious diseases. Combinatorial adjuvants have gained increasing interest as they can stimulate multiple immune pathways and enhance the vaccine efficacy of subunit vaccines. We investigated the adjuvanticity of Aluminum (alum) in combination with rASP-1, a protein adjuvant, using the Middle East respiratory syndrome coronavirus MERS-CoV receptor-binding-domain (RBD) vaccine antigen. A highly enhanced anti-MERS-CoV neutralizing antibody response was induced when mice were immunized with rASP-1 and the alum-adjuvanted RBD vaccine in two separate injection sites as compared to mice immunized with RBD + rASP-1 + alum formulated into a single inoculum. The antibodies produced also significantly inhibited the binding of RBD to its cell-associated receptor. Moreover, immunization with rASP-1 co-administered with the alum-adjuvanted RBD vaccine in separate sites resulted in an enhanced frequency of TfH and GC B cells within the draining lymph nodes, both of which were positively associated with the titers of the neutralizing antibody response related to anti-MERS-CoV protective immunity. Our findings not only indicate that this unique combinatorial adjuvanted RBD vaccine regimen improved the immunogenicity of RBD, but also point to the importance of utilizing combinatorial adjuvants for the induction of synergistic protective immune responses.

A novel electrophoretic immunoblot as antigen desorption and quantification method for alum-adjuvanted veterinary rabies vaccines

Rabies vaccines for domestic animals are adjuvanted with aluminum salts. A particular challenge for in-vitro batch potency tests with these products is the fact that the antigens are firmly adsorbed to the aluminum salt matrix and thus are not easily available for antigen quantification. In the current manuscript we describe a versatile technique to quantify antigens in aluminum adsorbed vaccine formulations. A combined electrophoretic desorption and blotting method is presented that transfers the antigens to a nitrocellulose membrane followed by an immunoblot quantification of the transferred rabies antigens. For the immunoblot a rabies G-protein specific, monoclonal antibody is used that by itself has neutralizing activity. This ensures that only relevant antigens are quantified. By comparing end products with non-adjuvanted in-process material it can be demonstrated that the antigens are quantitatively desorbed from the adjuvant matrix. Resuts of the new antigen quantification method were compared with the outcome of the serological batch potency test as described in the European Pharmacopoeia. It is demonstrated that the new antigen quantification method reveals relevant differences between experimental vaccine batches formulated with increasing antigen loads. This proves the broad detection range of the method. In general, the results show that this highly versatile technique can serve as an important component of a comprehensive consistency test strategy and may be applied in a modified form to any alum-adjuvanted vaccine.

Immunogenicity of a Purified Inactivated Zika Virus Vaccine Candidate in Humans is Diminished by Priming with a Yellow Fever or Japanese Encephalitis Virus Vaccine: Elucidating Immunologic Interference between Flavivirus Vaccines

Abstract In response to the 2016 Zika virus (ZIKV) outbreak, we developed a purified, formalin-inactivated, Alum-adjuvanted ZIKV vaccine (ZPIV) candidate that was protective in animal models and advanced to human testing in four phase 1 clinical trials. We have previously reported the interim analysis of three trials. Here we present the final analysis of a phase 1, placebo controlled, double-blind trial of ZPIV. Seventy-five flavivirus-naïve adults—divided into three groups of 25—were randomly assigned to receive three 5μg doses of ZPIV or placebo at days 1, 29 and 196. Group 1 only received ZPIV, while Groups 2 and 3 first received either licensed Japanese encephalitis (IXIARO®) or yellow fever (YF-VAX®) vaccine two-months prior to receiving ZPIV. Immune responses were assessed by a live-virus microneutralization assay. ZPIV was well tolerated across groups. Group 1 exhibited neutralizing antibody (nAb) geometric mean titers (GMT) of 101 and 511 after the 2nd and 3rd doses. GMTs in Groups 2 and 3 were significantly lower at 11.8 and 6.6 after two doses, and 174 and 79 after the 3rd dose. There were no differences in binding antibody titers or in antibody affinity maturation across groups. These data suggest that flavivirus vaccine priming of B cells directed antibodies toward non-neutralizing epitopes and that decline in ZIKV nAb titers did not reflect overall decrements in B cell responses. Other studies have shown prior dengue virus infection boosts subsequent ZIKV responses. These results indicate the interplay of flavivirus immunity is contextual and likely specific to the mode and timing of antigen presentation. More studies are needed to investigate these factors, so as to optimize the rational use of vaccines against co-endemic flaviviruses.

The SENIEUR protocol and the efficacy of hepatitis B vaccination in healthy elderly persons by age, gender, and vaccine route

BackgroundReduced response to hepatitis B vaccines is associated with aging, confounding and comorbid conditions, as well as inadvertent subcutaneous (SC) inoculation. We hypothesized that the antibody and T cell-mediated immune responses (T-CMI) of elderly adults to a vaccine intended for intramuscular (IM) administration would be attenuated when deposited into SC fat, independent of confounding conditions.ResultsFifty-two healthy, community dwelling elderly adults (65–82 years), seronegative for HBV, were enrolled in the SENIEUR protocol as a strictly healthy population. These seniors were randomized to receive a licensed alum-adjuvanted recombinant HBV vaccine either SC or IM, with the inoculum site verified by imaging. The response rates, defined as hepatitis B surface antibodies (HBsAb) ≥10 IU/L, were significantly lower in the elderly than in young adults, a group of 12, healthy, 21–34-year-old volunteers. Moreover, elderly participants who received the vaccine IM were significantly more likely to be responders than those immunized SC (54% versus 16%, p = 0.008). The low seroconversion rate in the IM group progressively declined with increasing age, and responders had significantly lower HBsAb titers and limited isotype responses. Moreover, T-CMI (proliferation and cytokine production) were significantly reduced in both percentage of responders and intensity of the response for both Th1 and Th2 subsets in the elderly.ConclusionsOur data demonstrate the blunted immunogenicity of SC inoculation as measured by peak titers and response rates. Further, the qualitative and quantitative deficits in B- and T-CMI responses to primary alum adjuvanted protein antigens persisted even in strictly healthy elderly populations with verified IM placement compared to younger populations.Clinical trial registrationClinicalTrials.gov, NCT04162223. Registered 14 November 2019. Retrospectively registered.

A novel TLR7 agonist as adjuvant to stimulate high quality HBsAg-specific immune responses in an HBV mouse model

BackgroundThe global burden of hepatitis B virus (HBV) infection in terms of morbidity and mortality is immense. Novel treatments that can induce a protective immune response are urgently needed to effectively control the HBV epidemic and eventually eradicate chronic HBV infection.MethodsWe designed and evaluated an HBV therapeutic vaccine consisting of a novel Toll-like receptor 7 (TLR7) agonist T7-EA, an Alum adjuvant and a recombinant HBsAg protein. We used RNA-seq, ELISA and hTLR7/8 reporting assays to characterize T7-EA in vitro and real-time PCR to evaluate the tissue-retention characteristics in vivo. To evaluate the adjuvant potential, we administrated T7-EA intraperitoneally in a formulation with an Alum adjuvant and HBsAg in normal and HBV mice, then, we evaluated the HBsAg-specific immune responses by ELISA and Elispot assays.ResultsT7-EA acted as an hTLR7-specific agonist and induced a similar gene expression pattern as an unmodified TLR7 ligand when Raw 264.7 cells were exposed to T7-EA; however, T7-EA was more potent than the unmodified TLR7 ligand. In vivo studies showed that T7-EA had tissue-retaining activity with stimulating local cytokine and chemokine expression for up to 7 days. T7-EA could induce Th1-type immune responses, as evidenced by an increased HBsAg-specific IgG2a titer and a T-cell response in normal mice compared to mice received traditional Alum-adjuvant HBV vaccine. Importantly, T7-EA could break immune tolerance and induce persistent HBsAg-specific antibody and T-cell responses in an HBV mouse model.ConclusionsT7-EA might be a candidate adjuvant in a prophylactic and therapeutic HBV vaccine.

Recombinant PBP2a of methicillin-resistant S. aureus formulation in Alum and Montanide ISA266 adjuvants induced cellular and humoral immune responses with protection in Balb/C mice

Staphylococcus aureus is an important cause of both hospital and community acquired infections worldwide. S.aureus can develop multidrug resistance; thus, immunotherapy can be a rational alternative. High level β-lactam resistance of S. aureus has been attributed to the penicillin binding protein 2a (PBP2a). In this study, we assessed the immunogenicity and protectivity of PBP2a formulated in Montanide ISA266 and Alum adjuvants.Recombinant PBP2a with a molecular weight of approximately 13 kDa was expressed and purified by nickel-nitrilotriacetic acid (NI-NTA) affinity chromatography and characterized by SDS-PAGE and Western blot.To investigate the immunogenicity and protective effects of recombinant protein, 20 μg of r-PBP2a in various formulations were subcutaneously injected in different groups. Two booster vaccinations were carried out in two-week intervals and blood samples were collected two weeks after each injection. To determine the type of induced immune response, sera and splenocytes were analyzed by ELISA for total IgG and isotypes (IgG1 and IgG2a) and cytokine secretion (IFN-γ, IL-4, IL-17 and TNF-α), respectively. Three weeks following the last immunization, experimental mice were challenged with 5 × 108 CFU of bacteria intraperitoneally and mortality rate and bacterial load were assessed.Interestingly, analysis of humoral immune responses revealed that administration of r-PBP2a with Montanide ISA266 significantly increased specific IgG responses and also IgG1 isotype compared to alum-adjuvanted vaccine group. Also, r-PBP2a formulation with alum and MontanideISA266 adjuvants raised IFN-γ, IL-4, IL-17 cytokines secretion, and protectivity following experimental challenge.The results of the present study provide evidences for immunogenicity and protectivity of PBP2a protein as a vaccine candidate.

Adjuvant effect of TLR7 agonist adsorbed on aluminum hydroxide (AS37): A phase I randomized, dose escalation study of an AS37-adjuvanted meningococcal C conjugated vaccine

An adjuvant system (AS37) has been developed containing a synthetic toll-like receptor agonist (TLR7a). We conducted a phase I randomized, observer-blind, dose-escalation study to assess the safety and immunogenicity of an investigational AS37-adjuvanted meningococcus C (MenC) conjugate vaccine in healthy adults (NCT02639351). A control group received a licensed MenC conjugate alum-adjuvanted vaccine. Eighty participants were randomized to receive one dose of control or investigational vaccine containing AS37 (TLR7a dose 12.5, 25, 50, 100 μg). All vaccines were well tolerated, apart from in the TLR7a 100 μg dose group, which had three reports (18.8%) of severe systemic adverse events. Four weeks after vaccination, human complement serum bactericidal assay seroresponse rates against MenC were 56–81% in all groups, and ELISA seroresponses were ≥81% for all AS37-adjuvanted vaccine groups (100% in 50 and 100 μg dose groups) and 88% in the control group. Antibody responses were maintained at six months after vaccination.

Evaluation of inactivated vaccine against fowl cholera developed from local isolates of Pasteurella multocida in Ethiopia

Fowl cholera caused by Pasteurella multocida is among the serious infectious diseases of poultry in Ethiopia. This study was conducted to develop a vaccine from local strains of P. multocida and evaluate its performance. Inactivated vaccine was prepared following the OIE standards in three adjuvant formulations (oil, alum and gel). The performance of the different formulations was evaluated at different dose rates (0.5 and 1 mL) and routes (subcutaneous, SC and interamuscular, IM) in vaccination-challenge experiment in a total of 160 (six weeks old) chicken. The vaccinated groups showed significantly higher (P<0.05) mean antibody titer at day 21 (1365.49±376.97) and day 35 (1707±193.95) post-vaccination compared to the mean value at day 0 (200.01±4.91) and that of the unvaccinated group (196.72±10.51.147). The highest antibody titer obtained was for group vaccinated with 0.5 mL of alum-adjuvanted vaccine given IM (2472.96±603.47). The differences in antibody titer among vaccinated groups with respect to types of adjuvant and dose rates were insignificant. All vaccine formulations provided significant protection with survival rates ranging from 80 to 100% with alum-adjuvanted vaccine given IM being superior both in protective efficacy (100%) and in the absence of clinical signs post-challenge indicating its potential application in the control of fowl cholera. Key words: Cholera, Pasteurella multocida, vaccines, poultry, Ethiopia.

An adult gerbil model for evaluating potential coxsackievirus A16 vaccine candidates

A suitable animal model of CVA16 infection is crucial in order to understand its pathogenesis and to help develop antiviral vaccines or screen therapeutic drugs. The neonatal mouse model has a short sensitivity period to CA16 infection, which is a major limitation. In this study, we demonstrate that adult (60-day-old) gerbils are susceptible to CVA16 infection at high doses (108.0 TCID50). A clinical isolate strain of CVA16 was inoculated intraperitoneally into adult gerbils, which subsequently developed significant clinical symptoms, including hind limb weakness, paralysis of one or both hind limbs, tremors, and eventual death from neurological disorders. Real-time RT-PCR revealed that viral loads in the spinal cord and brainstem were higher than those in other organs/tissues. Histopathological changes, such as neuronal degeneration, neuronal loss, and neuronophagia, were observed in the spinal cord, brainstem, and heart muscle, along with necrotizing myositis. Gerbils receiving both prime and boost immunizations of alum adjuvant inactivated vaccine exhibited no clinical signs of disease or mortality following challenge by CVA16, whereas 80% of control animals showed obvious clinical signs, including slowness, paralysis of one or both hind limbs, and eventual death, suggesting that the CVA16 vaccine can fully protect gerbils against CVA16 challenge. These results demonstrate that an adult gerbil model provides us with a useful tool for studying the pathogenesis and evaluating antiviral reagents of CVA16 infection. The development of this animal model would also be conducive to screening promising CVA16 vaccine candidates as well as further vaccination evaluation.

2287. Recently Approved HEPLISAV-B(R) [Hepatitis B Vaccine (Recombinant), Adjuvanted] Shows a Higher Proportion of Subjects Achieving Seroprotection With a More Consistent Immune Response Compared With Engerix-B(R) [Hepatitis B Vaccine (Recombinant)] in Three Comparative Trials

BackgroundHEPLISAV-B® [hepatitis B vaccine (recombinant), adjuvanted] uses a cytidine phospho-guanosine (CpG) oligonucleotide or “1018,” a Toll-like receptor 9 agonist, as an adjuvant. Engerix-B® [hepatitis B vaccine (recombinant)], as well as other hepatitis B vaccines, use alum. HEPLISAV-B, a 2-dose vaccine given at Weeks 0 and 4, was recently approved for use in adults ≥18 years for the prevention of hepatitis B. Approval of HEPLISAV-B was based on three pivotal phase 3 noninferiority trials, comparing it with Engerix-B, a 3-dose vaccine given at Day 0, Day 30, and 6 months. Immunogenicity and safety results for these trials, HBV-10, HBV-16 and HBV-23, have been published previously; the safety of HEPLISAV-B was generally similar to Engerix-B.MethodsThe 3 randomized trials were observer-blinded and collectively included subjects aged 18–70 years. Immunogenicity analysis based on antibody against hepatitis B surface antigen (anti-HBs) levels were based on the per-protocol analysis. Presented here are reverse cumulative frequency plots of anti-HBs serum concentrations for the 3 trials.ResultsAcross the trials, reverse cumulative frequency plots of anti-HBs concentrations showed a higher proportion (>90%) of HEPLISAV-B subjects developed a seroprotective antibody level (anti-HBs levels ≥10 mIU/mL) compared with Engerix-B subjects (80% to ~90%). A higher proportion of HEPLISAV-B subjects had anti-HBs levels between 10 mIU/mL and 1,000 mIU/mL. While a higher proportion of Engerix-B subjects had anti-HBs levels >1,000 mIU/mL, a significantly higher proportion of Engerix-B subjects did not develop seroprotective antibody levels. The response curves indicate a more consistent immune response with a higher percentage of subjects achieving seroprotection with less variability for HEPLISAV-B compared with Engerix-B, which showed a more variable response and fewer subjects achieving seroprotection.ConclusionHEPLISAV-B, using a CpG adjuvant, results in a higher percentage of persons achieving seroprotection and produces a more uniform and consistent induction of protective antibody levels than Engerix-B, an alum-adjuvanted vaccine. Disclosures R. N. Hyer, Dynavax Technologies Corporation: Employee and Shareholder, Salary and Stock options. R. Janssen, Dynavax Technologies Corporation: Employee and Shareholder, Salary and Stock options.

Affinity Maturation Is Impaired by Natural Killer Cell Suppression of Germinal Centers

SUMMARYSomatic hypermutation of immunoglobulin sequences in germinal center (GC) reactions must be optimized to elicit high-affinity, protective antibodies after vaccination. We expose natural killer (NK) cells as robust negative regulators of somatic hypermutation in antigen-reactive B cells. NK cells restrict follicular helper T cell (TFH) and GC B cell frequencies and titers of antigen-specific immunoglobulin after administration of alum-adjuvanted hapten-protein conjugate vaccines. This inhibition is perforin dependent, suggesting that NK cells kill one or more cells critical for GC development. In the presence of perforin-competent NK cells, antigen-specific GC B cells acquire fewer mutations, including less frequent generation of non-synonymous substitu-tions and mutations associated with increased antibody affinity. Thus, NK cells limit the magnitude of GC reactions and thereby restrain vaccine elicitation of high-affinity antibodies. Circumventing this activity of NK cells during vaccination has strong potential to enhance humoral immunity and facilitate vaccine-elicited prevention of disease.

Feline Injection Site Sarcomas: Data from Switzerland 2009–2014

Feline injection site sarcomas (FISS) were first described in the early 1990s. Despite extensive research, the pathogenesis of these tumours has not been elucidated conclusively. Their appearance and the marked increase in their incidence has been mainly connected to the injection of vaccines,and it is assumed that a chronic inflammatory reaction at the injection site triggers subsequent malignant transformation. The role of alum-based adjuvants has been discussed, but is controversial. The present study of the Swiss Feline Cancer Registry (SFCR) with data from 2009 to 2014 revealed a marked decrease of the incidence of fibrosarcomas compared with the previous observation period. Notably, this drop occurred after a non-adjuvanted feline leukaemia virus vaccine was introduced in Switzerland in 2007. This observation, together with the previous findings of the SFCR, further supports the notion that alum-adjuvanted vaccines are involved in the genesis of FISS and that non-adjuvanted vaccines might be safer for cats.

Pasteurella multocida inactivated with ferric chloride and adjuvanted with bacterial DNA is a potent and efficacious vaccine in Balb/c mice.

Pasteurella multocida (P. multocida) is a principal pathogen of domestic animals and an opportunistic pathogen of humans. It is the causative agent of pneumonia and haemorrhagic septicaemia in cattle, sheep and goats, fowl cholera in chickens and progressive atrophic rhinitis in swine. In this study, we investigated the humoral and cellular immune responses and protective immunity conferred by an iron-inactivated vaccine with bacterial DNA (IIV+bDNA) as an adjuvant in mice. P. multocida was grown in BHI broth, inactivated with formalin and FeCl3 and adjuvanted with alum and bDNA. Mice were immunized with two whole-cell inactivated vaccine doses 2 weeks apart. The animals were challenged 4 weeks after booster immunization. Immunogens (vaccines and bDNA) posed no safety problems when mice were injected subcutaneously (s/c) with these preparations. The serum antibody titres were tested by ELISA. At 28 days post immunization, cell-mediated immunity responses were determined. The responses were measured by assay of IL-6 and IL-12 in lymphocyte spleen culture supernatants. ELISA results showed that the levels of antibodies in iron inactivated with bDNA adjuvant groups were higher than in the formalin inactivated with alum adjuvant vaccine group. The protection rate of IIV+bDNA adjuvant vaccine was superior to that of the other vaccines and it protected 100 % of the challenge group mice. Following immunization, bDNA promoted increased production of interleukins compared to the control groups. These studies indicate that bDNA is effective as an immune adjuvant, and along with stimulatory bDNA represent promising new humoral and cellular immune enhancers for vaccination applications. In addition, this vaccine is able to provide long-term protection against infection.

Intranasal immunization with an acellular pertussis vaccine containing a Th1/17 skewing adjuvant, BcfA, improves B. pertussis clearance from the mouse respiratory tract.

Abstract Bordetella pertussis is the causative agent of whooping cough, a resurging vaccine-preventable disease. This highly contagious disease is most severe in infants and young children. Current alum-adjuvanted acellular pertussis vaccines (aPV) prevent severe disease but do not prevent nasal carriage and subsequent person-to-person pathogen transmission. The Th1/2 skewed immune response induced by aPV is one potential explanation for this failure. We are testing the hypothesis that modification of current aPV by the addition of an adjuvant, BcfA, that skews immune responses towards the more protective Th1/17 phenotype will improve protection. We also hypothesize that changing the delivery route from intramuscular (i.m) to intranasal (i.n) administration will generate mucosal immunity and further improve protection. In the established mouse model of B. pertussis infection, we found that i.m. immunization of mice with an experimental aPV containing BcfA and alum as the adjuvants significantly reduced bacterial numbers in the lungs compared to an alum-adjuvanted vaccine alone. Further, i.n administration of the BcfA+alum containing vaccine provided better protection against colonization of the trachea and lungs than i.m. immunization. Alum-induced Th2 cytokine responses were reduced by addition of BcfA, and were further reduced by i.n. vaccine delivery. Thus, a revised aPV that includes BcfA, administered i.n, may improve protection against B. pertussis infection compared with current formulations and delivery method.

Allergic patients with and without allergen-specific immunotherapy mount protective immune responses to tick-borne encephalitis vaccination in absence of enhanced side effects or propagation of their Th2 bias

BackgroundAllergic diseases are caused by Th2-driven immune responses and their treatment with specific immunotherapy (SIT) leads to immunomodulation via IL10, TGF-ß and Th1/Tr1 shift. This phase IV, open-label clinical trial investigated whether allergies and SIT treatment influenced immune responses to routine vaccination. MethodsWe studied three groups: 49 allergic patients (allergic group), 21 allergic patients receiving maintenance doses of SIT (SIT group), and 49 non-allergic controls. All subjects received tick-borne encephalitis (TBE) booster vaccines and humoral and cellular immune responses were evaluated after one week, four weeks and six months. ResultsThe levels and kinetics of neutralizing TBE-specific antibodies, reflecting protection against TBE, were not significantly different in the three groups. The allergic group showed Th2 polarization pre-booster as indicated by increased TBE-specific IgG1 and elevated mitogen-induced IL5 production. Alum-adjuvanted TBE vaccine led to Th2 biased immune responses in the controls, but to no further enhancement of Th2 polarization in the allergic and SIT group. Furthermore, in the SIT group cellular parameters reflected the induction of immunomodulation due to increased Tregs, elevated baseline IL10 and lack of TBE-specific IL5. Importantly, these cellular regulatory responses did not limit the ability to mount sufficient TBE-specific antibodies after the booster. All groups tolerated the vaccine well with no exacerbation of allergic symptoms. ConclusionTBE booster vaccinations were immunogenic and safe in both the allergic and SIT group and contributed to balanced immune responses. Our data indicate that all allergic patients, even when undergoing SIT, should be vaccinated without hesitation and at regular intervals according to standard recommendations.ClinicalTrials.gov (NCT02511535).

Safety of a two-dose investigational hepatitis B vaccine, HBsAg-1018, using a toll-like receptor 9 agonist adjuvant in adults

BackgroundHepatitis B virus infection remains an important global public health problem. Approved alum-adjuvanted vaccines are well tolerated but require three doses and have reduced immunogenicity in adults. A two-dose vaccine containing hepatitis B surface antigen combined with a novel, Toll-like receptor 9 agonist adjuvant (HBsAg-1018 [HEPLISAV–B®]) has demonstrated significantly higher seroprotection rates than a three dose vaccine. MethodsA post hoc analysis compared the safety of HBsAg-1018 with HBsAg-Eng (Engerix-B®), in three randomized, observer-blinded, active-controlled, multi-center phase 3 trials in adults. HBsAg-1018 was administered intramuscularly at weeks 0 and 4 and placebo at week 24 and HBsAg-Eng at weeks 0, 4, and 24. ResultsPost-injection reactions, adverse events, medically attended adverse events, and new-onset immune-mediated adverse events were balanced between vaccine groups. Anti-nuclear antibodies, anti-double stranded DNA antibodies, anti-neutrophil cytoplasmic antibodies, and antiphospholipid antibodies were balanced between groups. A transient increase in anti-beta2 glycoprotein 1 IgM was observed in the HBsAg-1018 group but was not associated with a thrombotic event. Serious adverse events and deaths were generally balanced between groups. ConclusionHBsAg-1018 had a similar safety profile to HBsAg-Eng. With improved immunogenicity and fewer doses over a shorter time, HBsAg-1018 has the potential to provide improved seroprotection and a significant public health benefit to adults 18 years of age or older.

Immunogenicity of a two-dose investigational hepatitis B vaccine, HBsAg-1018, using a toll-like receptor 9 agonist adjuvant compared with a licensed hepatitis B vaccine in adults

BackgroundHepatitis B virus infection remains an important public health problem in the United States. Currently approved alum-adjuvanted vaccines require three doses and have reduced immunogenicity in adults, particularly in those who have diabetes mellitus, or are older, male, obese, or who smoke. MethodsPhase 3 observer–blinded, randomized (2:1 HBsAg-1018 [HEPLISAV-B™]:HBsAg-Eng [Engerix-B®]), active–controlled trial in adults 18–70 years of age. HBsAg-1018 was administered intramuscularly at weeks 0 and 4 and placebo at week 24 and HBsAg-Eng at weeks 0, 4, and 24. The primary immunogenicity endpoint assessed the noninferiority of the seroprotection rate at week 28 in participants with type 2 diabetes mellitus. Secondary endpoints included seroprotection rates in the total trial population and by age, sex, body mass index, and smoking status. ResultsAmong 8374 participants randomized, 961 participants in the per-protocol population had type 2 diabetes mellitus. In diabetes participants, the seroprotection rate in the HBsAg-1018 group at week 28 was 90.0%, compared with 65.1% in the HBsAg-Eng group, with a difference of 24.9% (95% CI: 19.3%, 30.7%), which met the prospectively-defined criteria for noninferiority and statistical significance. In the total study per-protocol population (N = 6826) and each pre-specified subpopulation, the seroprotection rate in the HBsAg-1018 group was statistically significantly higher than in the HBsAg-Eng group. ConclusionTwo doses of HBsAg-1018, administered over 4 weeks, induced significantly higher seroprotection rates than three doses of HBsAg-Eng, given over 24 weeks, in adults with factors known to reduce the immune response to hepatitis B vaccines as well as in those without those factors. With fewer doses in a shorter time, and greater immunogenicity, HBsAg-1018 has the potential to significantly improve protection against hepatitis B in adults at risk for hepatitis B infection.Trial Registration clinicaltrials.gov Identifier: NCT02117934.