scholarly journals Despite egg-adaptive mutations, the 2012-13 H3N2 influenza vaccine induced comparable antibody titers to the intended strain

2017 ◽  
Author(s):  
Sarah Cobey ◽  
Kaela Parkhouse ◽  
Benjamin S. Chambers ◽  
Hildegund C. Ertl ◽  
Kenneth E. Schmader ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Protective Immunity ◽  
Adaptive Mutations ◽  
Before And After ◽  
Antibody Titers ◽  
H3n2 Influenza ◽  
Subtype A ◽  
Protection Against Infection ◽  
Actual Vaccine

AbstractBackgroundInfluenza vaccination aims to prevent infection by influenza virus and reduce associated morbidity and mortality; however, vaccine effectiveness (VE) can be modest, especially for subtype A/H3N2. Failure to achieve consistently high VE has been attributed both to mismatches between the vaccine and circulating influenza strains and to the vaccine's elicitation of protective immunity in only a subset of the population. The low H3N2 VE in 2012-13 was attributed to egg-adaptive mutations that created antigenic mismatch between the intended (A/Victoria/361/2011) and actual vaccine strain (IVR-165).MethodsWe investigate the basis of the low VE in 2012-2013 by evaluating whether vaccinated and unvaccinated individuals were infected by different viral strains and assessing the serologic responses to A/Victoria/361/2011 and the IVR-165 vaccine strain in an adult cohort before and after vaccination.ResultsWe found no significant genetic differences between the strains that infected vaccinated and unvaccinated individuals. Vaccination increased titers to A/Victoria/361/2011 as much as to IVR-165. These results are consistent with the hypothesis that vaccination served merely to boost preexisting cross-reactive immune responses, which provided limited protection against infection with the circulating influenza strains.ConclusionsIn contrast to suggestive analyses based on ferret antisera, low H3N2 VE in 2012-13 does not appear to be due to the failure of the egg-adapted strain to induce a response to the intended vaccine strain. Instead, low VE might have been caused by the emergence of anti-genically novel influenza strains and low vaccine immunogenicity in a subset of the population.

scholarly journals Correlates of Immune Protection following Cutaneous Immunization with an Attenuated Burkholderia pseudomallei Vaccine

2013 ◽  
Vol 81 (12) ◽  
pp. 4626-4634 ◽  
Author(s):  
Ediane B. Silva ◽  
Andrew Goodyear ◽  
Marjorie D. Sutherland ◽  
Nicole L. Podnecky ◽  
Mercedes Gonzalez-Juarrero ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Protective Immunity ◽  
Burkholderia Pseudomallei ◽  
Partial Protection ◽  
Content Type ◽  
Humoral Immune ◽  
Humoral Immune Responses ◽  
Immune Correlates ◽  
Draining Lymph Nodes

ABSTRACTInfections with the Gram-negative bacteriumBurkholderia pseudomallei(melioidosis) are associated with high mortality, and there is currently no approved vaccine to prevent the development of melioidosis in humans. Infected patients also do not develop protective immunity to reinfection, and some individuals will develop chronic, subclinical infections withB. pseudomallei. At present, our understanding of what constitutes effective protective immunity againstB. pseudomalleiinfection remains incomplete. Therefore, we conducted a study to elucidate immune correlates of vaccine-induced protective immunity against acuteB. pseudomalleiinfection. BALB/c and C57BL/6 mice were immunized subcutaneously with a highly attenuated, Select Agent-excludedpurMdeletion mutant ofB. pseudomallei(strain Bp82) and then subjected to intranasal challenge with virulentB. pseudomalleistrain 1026b. Immunization with Bp82 generated significant protection from challenge withB. pseudomallei, and protection was associated with a significant reduction in bacterial burden in lungs, liver, and spleen of immunized mice. Humoral immunity was critically important for vaccine-induced protection, as mice lacking B cells were not protected by immunization and serum from Bp82-vaccinated mice could transfer partial protection to nonvaccinated animals. In contrast, vaccine-induced protective immunity was found to be independent of both CD4 and CD8 T cells. Tracking studies demonstrated uptake of the Bp82 vaccine strain predominately by neutrophils in vaccine-draining lymph nodes and by smaller numbers of dendritic cells (DC) and monocytes. We concluded that protection following cutaneous immunization with a live attenuatedBurkholderiavaccine strain was dependent primarily on generation of effective humoral immune responses.

scholarly journals Identification of Surrogates and Correlates of Protection in Protective Immunity againstMycobacterium bovisInfection Induced in Neonatal Calves by Vaccination withM. bovisBCG Pasteur andM. bovisBCG Danish

2011 ◽  
Vol 18 (3) ◽  
pp. 373-379 ◽  
Author(s):  
J. C. Hope ◽  
M. L. Thom ◽  
M. McAulay ◽  
E. Mead ◽  
H. M. Vordermeier ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Immune Responses ◽  
Protective Immunity ◽  
Protective Efficacy ◽  
Significant Degree ◽  
Degree Of Protection ◽  
Correlates Of Protection ◽  
Ifn Γ ◽  
Neonatal Calves ◽  
Protection Against Infection

ABSTRACTVaccination of neonatal calves withMycobacterium bovisbacillus Calmette-Guérin (BCG) induces a significant degree of protection against infection with virulentM. bovis, the causative agent of bovine tuberculosis (bTB). We compared two strains of BCG, Pasteur and Danish, in order to confirm that the current European human vaccine strain (BCG Danish) induced protective immunity in calves, and we assessed immune responses to determine correlates of protection that could assist future vaccine evaluation in cattle. Both vaccine strains induced antigen (purified protein derivate [PPD])-specific gamma interferon (IFN-γ) in whole-blood cultures. These responses were not significantly different for BCG Pasteur and BCG Danish and peaked at week 2 to 4 postvaccination. Vaccination with either BCG Danish or BCG Pasteur induced significant protection against bTB, with reductions in both lesion score and bacteriological burden evident in both groups of vaccinated calves compared with nonvaccinated control calves. Measurement of IFN-γ-expressing T lymphocytes postvaccination and postchallenge revealed both correlates and surrogates of protective efficacy. The frequency of central memory T lymphocytes present at 12 weeks postvaccination (at the time ofM. bovischallenge) correlated significantly with protection. Conversely, the number of IFN-γ-expressing effector T cells present afterM. bovischallenge was correlated with disease. These results demonstrate that vaccination of neonatal calves with either BCG Pasteur or BCG Danish induces protective immune responses against TB. In addition, we show that measurement of antigen-specific T lymphocyte populations may provide a reliable means for identifying protective vaccine candidates.

scholarly journals 33. Intranasal M2SR (M2-deficient Single Replication) Live H3N2 Influenza Investigational Vaccine Induces Serum HAI & Broad Immune Responses in High Proportion of Adults

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S40-S41
Author(s):  
Joseph Eiden ◽  
Ruth Ellis ◽  
Carlos Fierro ◽  
Howard Schwartz ◽  
Mark Adams ◽  
...  
Keyword(s):  
Immune Responses ◽  
Geometric Mean ◽  
Surrogate Marker ◽  
Secretory Iga ◽  
Human Influenza ◽  
Dose Escalation Study ◽  
Challenge Study ◽  
Antibody Titers ◽  
Protection Against Infection ◽  
Dose Levels

Abstract Background A single intranasal (IN) dose of 108 TCID50 M2SR protected a responder subset of adults against infection and disease in a prior human influenza challenge study (EudraCT number: 2017-004971-30). Higher dose levels of M2SR were assessed in this phase 1b study to enhance immune responses and further increase protection levels in adults. Methods A double-blind, randomized, placebo-controlled dose escalation study (NCT03999554) was conducted at 4 US study sites with two different H3N2 M2SR vaccines that contained HA & NA from either A/Brisbane/10/2007 or A/Singapore/INFIMH-16–0019/2016. Serosusceptible 18–49 year old subjects (n = 206) received 2 IN doses of either saline or 1 of 3 different dose levels of vaccine (108 – 109 TCID50), administered 28 days apart. Results Study vaccination was well-tolerated at all dose levels. A single 109 dose of A/Singapore/2016 M2SR generated significantly increased serum HAI responses compared to the 108 dose of A/Brisbane/10/2007 M2SR that had provided protection against infection & illness in an earlier human influenza challenge study (Fig. 1). HAI titers ≥40 were achieved in 0%, 23% & 58% of subjects after the first dose of placebo, 108 or 109 M2SR, respectively (p< 0.003). Increases also were stimulated in serum microneutralization titers (MNT) to drifted strains of H3N2 (Fig 2) & in serum NAI (Fig 3) and mucosal sIgA (Fig 4) titers. Further increases in serum and mucosal immune response were noted after a 2nd IN vaccination. Proportion of subjects with seroprotective HAI titers after vaccination Proportion of subjects with increased microneutralization titers against drifted H3N2 viruses after vaccination Geometric mean fold rise in serum neuraminidase inhibition antibody titers after vaccination Conclusion An earlier clinical trial with a 108 dose of M2SR provided protection against infection and illness upon challenge with a highly drifted strain of H3N2. Protection correlated with vaccine induced serum MNT responses. In the current study, a single, 109 dose of M2SR significantly increased serum MNT, HAI & NAI titers as well as mucosal immune responses among greater proportions of study subjects. Since HAI, alone, is a well-accepted surrogate marker for vaccine protection against influenza, these broader enhancements indicate the potential for M2SR to protect against both matched and drifted strains of influenza in a high proportion of adults and strongly support clinical assessment in younger and older age groups as well as development of multivalent M2SR. Geometric mean fold rise in nasal mucosal secretory IgA antibody titers after vaccination Disclosures Joseph Eiden, MD, PhD, FluGen (Consultant) Ruth Ellis, MD, FluGen (Consultant) Roger Aitchison, ScM, FluGen (Consultant) Renee Herber, BS, FluGen (Employee) Pamuk Bilsel, PhD, FluGen (Employee)

scholarly journals In Vitro and In Vivo Analyses of Constitutive and In Vivo-Induced Promoters in Attenuated Vaccine and Vector Strains ofVibrio cholerae

2000 ◽  
Vol 68 (3) ◽  
pp. 1171-1175 ◽  
Author(s):  
Manohar John ◽  
Thomas I. Crean ◽  
Stephen B. Calderwood ◽  
Edward T. Ryan
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Antigen Expression ◽  
Live Attenuated Vaccine ◽  
Attenuated Vaccine ◽  
In Vivo Expression ◽  
Antibody Titers ◽  
Heterologous Antigens

ABSTRACT The optimal promoter for in vivo expression of heterologous antigens by live, attenuated vaccine vector strains of Vibrio cholerae is unclear; in vitro analyses of promoter activity may not accurately predict expression of antigens in vivo. We therefore introduced plasmids expressing the B subunit of cholera toxin (CtxB) under the control of a number of promoters into V. choleraevaccine strain Peru2. We evaluated the tac promoter, which is constitutively expressed in V. cholerae, as well as the in vivo-induced V. cholerae heat shock htpGpromoter and the in vivo-induced V. cholerae iron-regulatedirgA promoter. The functionality of all promoters was confirmed in vitro. In vitro antigenic expression was highest in vaccine strains expressing CtxB under the control of thetac promoter (2 to 5 μg/ml/unit of optical density at 600 nm [OD600]) and, under low-iron conditions, in strains containing the irgA promoter (5 μg/ml/OD600). We orally inoculated mice with the various vaccine strains and used anti-CtxB immune responses as a marker for in vivo expression of CtxB. The vaccine strain expressing CtxB under the control of thetac promoter elicited the most prominent specific anti-CtxB responses in vivo (serum immunoglobulin G [IgG], P≤ 0.05; serum IgA, P ≤ 0.05; stool IgA,P ≤ 0.05; bile IgA, P ≤ 0.05), despite the finding that the tac and irgApromoters expressed equivalent amounts of CtxB in vitro. Vibriocidal antibody titers were equivalent in all groups of animals. Our results indicate that in vitro assessment of antigen expression by vaccine and vector strains of V. cholerae may correlate poorly with immune responses in vivo and that of the promoters examined, thetac promoter may be best suited for expression from plasmids of at least certain heterologous antigens in such strains.

scholarly journals Paulownia tomentosa flower polysaccharide as an effective immunopotentiator to enhance immune responses for Newcastle disease vaccine in mice

2021 ◽  
Vol 33 (4) ◽  
pp. 11-20
Author(s):  
Xiaolan Chen ◽  
Junjie Jin ◽  
Fuxing Hao ◽  
Haifeng Yang ◽  
Hongxiang Sun ◽  
...  
Keyword(s):  
Immune Responses ◽  
Newcastle Disease ◽  
Interleukin 10 ◽  
Interferon Γ ◽  
Immunomodulatory Activity ◽  
Paulownia Tomentosa ◽  
Before And After ◽  
Antibody Titers ◽  
Spleen Lymphocytes ◽  
Ig G

To investigate the immunomodulatory activity and explore the mechanism of Paulownia tomentosa flower polysaccharides (PTFP). PTFP was orally administrated to mice for seven successive days before and after Newcastle disease vaccination. The results demonstrated that compared with the vaccine control (VC) group, PTFP enhanced the inhibition of hemagglutination assay antibody titers, promoted the antigen-specific immunoglobulin (Ig)G, IgG1, IgG2a, and IgG2b antibodies responses, enhanced proliferation of spleen T and B lymphocytes, increased the secretions of interferon-γ and interleukin-10 cytokines of spleen lymphocytes, and promoted the activation of natural killer cells. Therefore, PTFP, as an effective immunopotentiator, could induce a mixed T-helper (Th)1 and Th2 immune responses and an innate immune response.

scholarly journals What Constitutes Protective Immunity Following Yellow Fever Vaccination?

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 671
Author(s):  
Jolynne Mokaya ◽  
Derick Kimathi ◽  
Teresa Lambe ◽  
George M. Warimwe
Keyword(s):  
Immune Responses ◽  
Yellow Fever ◽  
Protective Immunity ◽  
Effective Vaccine ◽  
Published Data ◽  
Cell Mediated Immunity ◽  
Dosing Regimens ◽  
Antibody Titers ◽  
Tropical Areas ◽  
Yellow Fever Vaccination

Yellow fever (YF) remains a threat to global health, with an increasing number of major outbreaks in the tropical areas of the world over the recent past. In light of this, the Eliminate Yellow Fever Epidemics Strategy was established with the aim of protecting one billion people at risk of YF through vaccination by the year 2026. The current YF vaccine gives excellent protection, but its use is limited by shortages in supply due to the difficulties in producing the vaccine. There are good grounds for believing that alternative fractional dosing regimens can produce strong protection and overcome the problem of supply shortages as less vaccine is required per person. However, immune responses to these vaccination approaches are yet to be fully understood. In addition, published data on immune responses following YF vaccination have mostly quantified neutralising antibody titers. However, vaccine-induced antibodies can confer immunity through other antibody effector functions beyond neutralisation, and an effective vaccine is also likely to induce strong and persistent memory T cell responses. This review highlights the gaps in knowledge in the characterisation of YF vaccine-induced protective immunity in the absence or presence of neutralising antibodies. The assessment of biophysical antibody characteristics and cell-mediated immunity following YF vaccination could help provide a comprehensive landscape of YF vaccine-induced immunity and a better understanding of correlates of protective immunity.

Oral Immune Activation by Disgust and Disease-Related Pictures

2015 ◽  
Vol 29 (3) ◽  
pp. 119-129 ◽  
Author(s):  
Richard J. Stevenson ◽  
Deborah Hodgson ◽  
Megan J. Oaten ◽  
Luba Sominsky ◽  
Mehmet Mahmut ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Innate Immune Response ◽  
Negative Control ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Immune Markers ◽  
Before And After ◽  
Secondary Analyses ◽  
Image Set

Abstract. Both disgust and disease-related images appear able to induce an innate immune response but it is unclear whether these effects are independent or rely upon a common shared factor (e.g., disgust or disease-related cognitions). In this study we directly compared these two inductions using specifically generated sets of images. One set was disease-related but evoked little disgust, while the other set was disgust evoking but with less disease-relatedness. These two image sets were then compared to a third set, a negative control condition. Using a wholly within-subject design, participants viewed one image set per week, and provided saliva samples, before and after each viewing occasion, which were later analyzed for innate immune markers. We found that both the disease related and disgust images, relative to the negative control images, were not able to generate an innate immune response. However, secondary analyses revealed innate immune responses in participants with greater propensity to feel disgust following exposure to disease-related and disgusting images. These findings suggest that disgust images relatively free of disease-related themes, and disease-related images relatively free of disgust may be suboptimal cues for generating an innate immune response. Not only may this explain why disgust propensity mediates these effects, it may also imply a common pathway.

SUBTYPE A/H7N9 INFLUENZA: PATHOGENICITY AND PREVENTIVE MEASURES

2013 ◽  
pp. 95-100
Author(s):  
Dinh Binh Tran
Keyword(s):  
H7n9 Virus ◽  
Disease Symptoms ◽  
The People ◽  
High Risk Disease ◽  
Before And After ◽  
H7n9 Infection ◽  
Risk Of Disease ◽  
Tract Infections ◽  
Subtype A ◽  
Avian Populations

H7N9 is a serotype of the species Influenzavirus A. H7 virus normally circulates amongst avian populations with some variants known to occasionally infect humans. A H7N9 virus was first reported to have infected humans in 2013. The people with H7N9 virus are respiratory tract infections leading to pneumonia and can be death. To cope with H7N9 virus should strengthen supervision, strengthening management and treatment, epidemiological investigation and observe who has been exposed to the fatal cases. To limit the risk of disease, WHO recommends that people should be clean, safe eating, wash the hands often, especially before and after eating, after using the toilet, after contact with animals, after contact with sick people, use a mask when in contact with human or environmental exposure to the high-risk disease. Symptoms of influenza H7N9 infection are fever and cough then switch to pneumonia. Therefore, if having the symptoms like this, and then have the cough and shortness of breath, chest pain that should be early come the health facilities to diagnose and treat.

scholarly journals Next generation methodology for updating HA vaccines against emerging human seasonal influenza A(H3N2) viruses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James D. Allen ◽  
Ted M. Ross
Keyword(s):  
Influenza Virus ◽  
Immune Responses ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Influenza Viruses ◽  
Next Generation ◽  
Virus Infections ◽  
Wild Type ◽  
Influenza Hemagglutinin ◽  
H3n2 Influenza

AbstractWhile vaccines remain the best tool for preventing influenza virus infections, they have demonstrated low to moderate effectiveness in recent years. Seasonal influenza vaccines typically consist of wild-type influenza A and B viruses that are limited in their ability to elicit protective immune responses against co-circulating influenza virus variant strains. Improved influenza virus vaccines need to elicit protective immune responses against multiple influenza virus drift variants within each season. Broadly reactive vaccine candidates potentially provide a solution to this problem, but their efficacy may begin to wane as influenza viruses naturally mutate through processes that mediates drift. Thus, it is necessary to develop a method that commercial vaccine manufacturers can use to update broadly reactive vaccine antigens to better protect against future and currently circulating viral variants. Building upon the COBRA technology, nine next-generation H3N2 influenza hemagglutinin (HA) vaccines were designed using a next generation algorithm and design methodology. These next-generation broadly reactive COBRA H3 HA vaccines were superior to wild-type HA vaccines at eliciting antibodies with high HAI activity against a panel of historical and co-circulating H3N2 influenza viruses isolated over the last 15 years, as well as the ability to neutralize future emerging H3N2 isolates.

scholarly journals TolC-Dependent Modulation of Host Cell Death by the Francisella tularensis Live Vaccine Strain

2014 ◽  
Vol 82 (5) ◽  
pp. 2068-2078 ◽  
Author(s):  
Christopher R. Doyle ◽  
Ji-An Pan ◽  
Patricio Mena ◽  
Wei-Xing Zong ◽  
David G. Thanassi
Keyword(s):  
Cell Death ◽  
Immune Responses ◽  
Host Cell ◽  
Francisella Tularensis ◽  
Vaccine Strain ◽  
Live Vaccine ◽  
Live Vaccine Strain ◽  
Type I ◽  
Content Type ◽  
Host Cell Death

ABSTRACTFrancisella tularensisis a facultative intracellular, Gram-negative pathogen and the causative agent of tularemia. We previously identified TolC as a virulence factor of theF. tularensislive vaccine strain (LVS) and demonstrated that a ΔtolCmutant exhibits increased cytotoxicity toward host cells and elicits increased proinflammatory responses compared to those of the wild-type (WT) strain. TolC is the outer membrane channel component used by the type I secretion pathway to export toxins and other bacterial virulence factors. Here, we show that the LVS delays activation of the intrinsic apoptotic pathway in a TolC-dependent manner, both during infection of primary macrophages and during organ colonization in mice. The TolC-dependent delay in host cell death is required forF. tularensisto preserve its intracellular replicative niche. We demonstrate that TolC-mediated inhibition of apoptosis is an active process and not due to defects in the structural integrity of the ΔtolCmutant. These findings support a model wherein the immunomodulatory capacity ofF. tularensisrelies, at least in part, on TolC-secreted effectors. Finally, mice vaccinated with the ΔtolCLVS are protected from lethal challenge and clear challenge doses faster than WT-vaccinated mice, demonstrating that the altered host responses to primary infection with the ΔtolCmutant led to altered adaptive immune responses. Taken together, our data demonstrate that TolC is required for temporal modulation of host cell death during infection byF. tularensisand highlight how shifts in the magnitude and timing of host innate immune responses may lead to dramatic changes in the outcome of infection.

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