Matrix M Adjuvanted H5N1 Vaccine Elicits Broadly Neutralizing Antibodies and Neuraminidase Inhibiting Antibodies in Humans That Correlate With In Vivo Protection

The highly pathogenic avian influenza H5N1 viruses constantly evolve and give rise to novel variants that have caused widespread zoonotic outbreaks and sporadic human infections. Therefore, vaccines capable of eliciting broadly protective antibody responses are desired and under development. We here investigated the magnitude, kinetics and protective efficacy of the multi-faceted humoral immunity induced by vaccination in healthy adult volunteers with a Matrix M adjuvanted virosomal H5N1 vaccine. Vaccinees were given escalating doses of adjuvanted vaccine (1.5μg, 7.5μg, or 30μg), or a non-adjuvanted vaccine (30μg). An evaluation of sera from vaccinees against pseudotyped viruses covering all (sub)clades isolated from human H5N1 infections demonstrated that the adjuvanted vaccines (7.5μg and 30μg) could elicit rapid and robust increases of broadly cross-neutralizing antibodies against all clades. In addition, the adjuvanted vaccines also induced multifaceted antibody responses including hemagglutinin stalk domain specific, neuraminidase inhibiting, and antibody-dependent cellular cytotoxicity inducing antibodies. The lower adjuvanted dose (1.5µg) showed delayed kinetics, whilst the non-adjuvanted vaccine induced overall lower levels of antibody responses. Importantly, we demonstrate that human sera post vaccination with the adjuvanted (30μg) vaccine provided full protection against a lethal homologous virus challenge in mice. Of note, when combining our data from mice and humans we identified the neutralizing and neuraminidase inhibiting antibody titers as correlates of in vivo protection.

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Self-Assembling Nanovaccine Enhances Protective Efficacy Against CSFV in Pigs

Frontiers in Immunology ◽

10.3389/fimmu.2021.689187 ◽

2021 ◽

Vol 12 ◽

Author(s):

Ze-Hui Liu ◽

Hui-Ling Xu ◽

Guang-Wei Han ◽

Li-Na Tao ◽

Ying Lu ◽

...

Keyword(s):

Cellular Immunity ◽

Neutralizing Antibodies ◽

Protective Efficacy ◽

Genetically Engineered ◽

Swine Industry ◽

Antigen Uptake ◽

Virus Challenge ◽

Humoral And Cellular Immunity ◽

Self Assembling

Classical swine fever virus (CSFV) is a highly contagious pathogen, which pose continuous threat to the swine industry. Though most attenuated vaccines are effective, they fail to serologically distinguish between infected and vaccinated animals, hindering CSFV eradication. Beneficially, nanoparticles (NPs)-based vaccines resemble natural viruses in size and antigen structure, and offer an alternative tool to circumvent these limitations. Using self-assembling NPs as multimerization platforms provides a safe and immunogenic tool against infectious diseases. This study presented a novel strategy to display CSFV E2 glycoprotein on the surface of genetically engineered self-assembling NPs. Eukaryotic E2-fused protein (SP-E2-mi3) could self-assemble into uniform NPs as indicated in transmission electron microscope (TEM) and dynamic light scattering (DLS). SP-E2-mi3 NPs showed high stability at room temperature. This NP-based immunization resulted in enhanced antigen uptake and up-regulated production of immunostimulatory cytokines in antigen presenting cells (APCs). Moreover, the protective efficacy of SP-E2-mi3 NPs was evaluated in pigs. SP-E2-mi3 NPs significantly improved both humoral and cellular immunity, especially as indicated by the elevated CSFV-specific IFN-γ cellular immunity and >10-fold neutralizing antibodies as compared to monomeric E2. These observations were consistent to in vivo protection against CSFV lethal virus challenge in prime-boost immunization schedule. Further results revealed single dose of 10 μg of SP-E2-mi3 NPs provided considerable clinical protection against lethal virus challenge. In conclusion, these findings demonstrated that this NP-based technology has potential to enhance the potency of subunit vaccine, paving ways for nanovaccine development.

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Cell Culture-Derived Tilapia Lake Virus-Inactivated Vaccine Containing Montanide Adjuvant Provides High Protection against Viral Challenge for Tilapia

Vaccines ◽

10.3390/vaccines9020086 ◽

2021 ◽

Vol 9 (2) ◽

pp. 86

Author(s):

Weiwei Zeng ◽

Yingying Wang ◽

Huzi Hu ◽

Qing Wang ◽

Sven M. Bergmann ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Protective Efficacy ◽

Interferon Γ ◽

Economic Losses ◽

Mrna Levels ◽

Infectious Dose ◽

Booster Immunization ◽

Virus Challenge ◽

High Level ◽

Factor Α

Tilapia lake virus (TiLV) is a newly emerging pathogen responsible for high mortality and economic losses in the global tilapia industry. Currently, no antiviral therapy or vaccines are available for the control of this disease. The goal of the present study was to evaluate the immunological effects and protective efficacy of formaldehyde- and β-propiolactone-inactivated vaccines against TiLV in the presence and absence of the Montanide IMS 1312 VG adjuvant in tilapia. We found that β-propiolactone inactivation of viral particles generated a vaccine with a higher protection efficacy against virus challenge than did formaldehyde. The relative percent survivals of vaccinated fish at doses of 108, 107, and 106 50% tissue culture infectious dose (TCID50)/mL were 42.9%, 28.5%, and 14.3% in the absence of the adjuvant and 85.7%, 64.3%, and 32.1% in its presence, respectively. The vaccine generated specific IgM and neutralizing antibodies against TiLV at 3 weeks following immunization that were significantly increased after a second booster immunization. The steady state mRNA levels of the genes tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interferon γ (IFN-γ), cluster of differentiation 4 (CD4), major histocompatibility complex (MHC)-Ia, and MHC-II were all increased and indicated successful immune stimulation against TiLV. The vaccine also significantly lowered the viral loads and resulted in significant increases in survival, indicating that the vaccine may also inhibit viral proliferation as well as stimulate a protective antibody response. The β-propiolactone-inactivated TiLV vaccine coupled with the adjuvant Montanide IMS 1312 VG and booster immunizations can provide a high level of protection from virus challenge in tilapia.

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Probing neutralizing-antibody responses against emerging measles viruses (MVs): immune selection of MV by H protein-specific antibodies?

Journal of General Virology ◽

10.1099/vir.0.80467-0 ◽

2005 ◽

Vol 86 (2) ◽

pp. 365-374 ◽

Cited By ~ 37

Author(s):

Sabine Santibanez ◽

Stefan Niewiesk ◽

Alla Heider ◽

Jürgen Schneider-Schaulies ◽

Guy A. M. Berbers ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Measles Virus ◽

Protein A ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Neutralizing Capacity ◽

Human Sera ◽

H Protein ◽

Neutralizing Epitopes ◽

Selection Of

Measles virus (MV) infection and vaccination induce long-lasting immunity and neutralizing-antibody responses that are directed against the MV haemagglutinin (H) and the fusion (F) protein. A new MV genotype, D7, emerged recently in western Germany and rapidly replaced the long-term endemically circulating genotypes C2 and D6. Analysis of the H gene of C2, D6, D7 and vaccine viruses revealed uniform sequences for each genotype. Interestingly, a consistent exchange of seven distinct amino acids in the D7 H was observed when compared with residues shared between C2, D6 and vaccine viruses, and one exchange (D416→N) in the D7 H was associated with an additional N-linked glycosylation. In contrast, the F gene is highly conserved between MVs of these genotypes. To test whether the D7 H protein escapes from antibody responses that were raised against earlier circulating or vaccine viruses, the neutralizing capacity of mAbs recognizing seven distinct domains on the H of an Edmonston-related MV was compared. The mAbs revealed a selective and complete loss of two neutralizing epitopes on the D7 H when compared with C2, D6 and vaccine viruses. To assess whether these alterations of the D7 H affect the neutralizing capacity of polyclonal B-cell responses, genotype-specific antisera were produced in cotton rats. However, no significant genotype-dependent difference was found. Likewise, human sera obtained from vaccinees (n=7) and convalescents (n=6) did not distinguish between the MV genotypes. Although the hypothesis of selection of D7 viruses by pre-existing neutralizing antibodies is compatible with the differing pattern of neutralizing epitopes on the H protein, it was not confirmed by the results of MV neutralization with polyclonal sera.

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Field surveys in Croatia and North Macedonia reveal two novel phleboviruses circulating in sandflies

Journal of General Virology ◽

10.1099/jgv.0.001674 ◽

2021 ◽

Vol 102 (11) ◽

Author(s):

Nazli Ayhan ◽

Bulent Alten ◽

Vladimir Ivovic ◽

Aleksandar Cvetkovikj ◽

Jovana Stefanovska ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Experimental Studies ◽

Published Data ◽

Human Pathogens ◽

New Members ◽

The Balkans ◽

True Diversity ◽

Human Sera

Sandfly-borne phleboviruses are distributed widely throughout the Mediterranean Basin, presenting a threat to public health in areas where they circulate. However, the true diversity and distribution of pathogenic and apathogenic sandfly-borne phleboviruses remains a key issue to be studied. In the Balkans, most published data rely on serology-based studies although virus isolation has occasionally been reported. Here, we report the discovery of two novel sandfly-borne phleboviruses, provisionally named Zaba virus (ZABAV) and Bregalaka virus (BREV), which were isolated in Croatia and North Macedonia, respectively. This constitutes the first isolation of phleboviruses in both countries. Genetic analysis based on complete coding sequences indicated that ZABAV and BREV are distinct from each other and belong to the genus Phlebovirus, family Phenuiviridae. Phylogenetic and amino acid modelling of viral polymerase shows that ZABAV and BREV are new members of the Salehabad phlebovirus species and the Adana phlebovirus species, respectively. Moreover, sequence-based vector identification suggests that ZABAV is mainly transmitted by Phlebotomus neglectus and BREV is mainly transmitted by Phlebotomus perfiliewi. BREV neutralizing antibodies were detected in 3.3% of human sera with rates up to 16.7% in certain districts, demonstrating that BREV frequently infects humans in North Macedonia. In vitro viral growth kinetics experiments demonstrated viral replication of both viruses in mammalian and mosquito cells. In vivo experimental studies in mice suggest that ZABAV and BREV exhibit characteristics making them possible human pathogens.

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Differential Antigen Requirements for Protection against Systemic and Intranasal Vaccinia Virus Challenges in Mice

Journal of Virology ◽

10.1128/jvi.00353-08 ◽

2008 ◽

Vol 82 (14) ◽

pp. 6829-6837 ◽

Cited By ~ 24

Author(s):

David R. Kaufman ◽

Jaap Goudsmit ◽

Lennart Holterman ◽

Bonnie A. Ewald ◽

Matthew Denholtz ◽

...

Keyword(s):

Vaccinia Virus ◽

Neutralizing Antibodies ◽

Protective Immunity ◽

Recombinant Adenovirus ◽

Protective Efficacy ◽

Postexposure Prophylaxis ◽

Virus Challenge ◽

Protective Antigens ◽

A Subunit ◽

Potential Strategy

ABSTRACT The development of a subunit vaccine for smallpox represents a potential strategy to avoid the safety concerns associated with replication-competent vaccinia virus. Preclinical studies to date with subunit smallpox vaccine candidates, however, have been limited by incomplete information regarding protective antigens and the requirement for multiple boost immunizations to afford protective immunity. Here we explore the protective efficacy of replication-incompetent, recombinant adenovirus serotype 35 (rAd35) vectors expressing the vaccinia virus intracellular mature virion (IMV) antigens A27L and L1R and extracellular enveloped virion (EEV) antigens A33R and B5R in a murine vaccinia virus challenge model. A single immunization with the rAd35-L1R vector effectively protected mice against a lethal systemic vaccinia virus challenge. The rAd35-L1R vector also proved more efficacious than the combination of four rAd35 vectors expressing A27L, L1R, A33R, and B5R. Moreover, serum containing L1R-specific neutralizing antibodies afforded postexposure prophylaxis after systemic vaccinia virus infection. In contrast, the combination of rAd35-L1R and rAd35-B5R vectors was required to protect mice against a lethal intranasal vaccinia virus challenge, suggesting that both IMV- and EEV-specific immune responses are important following intranasal infection. Taken together, these data demonstrate that different protective antigens are required based on the route of vaccinia virus challenge. These studies also suggest that rAd vectors warrant further assessment as candidate subunit smallpox vaccines.

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Development of Safe and Non-Self-Immunogenic Mucosal Adjuvant by Recombinant Fusion of Cholera Toxin A1 Subunit with Protein Transduction Domain

Journal of Immunology Research ◽

10.1155/2018/9830701 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Byoung-Shik Shim ◽

In Su Cheon ◽

Eugene Lee ◽

Sung-Moo Park ◽

Youngjoo Choi ◽

...

Keyword(s):

Cholera Toxin ◽

Cytotoxic T Lymphocyte ◽

Antibody Responses ◽

Mucosal Vaccine ◽

Protein Transduction ◽

Protein Transduction Domain ◽

Igg Antibody ◽

Mucosal Adjuvant ◽

Virus Challenge

Potential use of cholera toxin (CT) as a mucosal vaccine adjuvant has been documented in a variety of animal models. However, native CT is highly toxic to be used as a mucosal adjuvant in humans. Here, we demonstrate a new approach to generate a mucosal adjuvant by replacing the B subunit of CT with HIV-1 Tat protein transduction domain (PTD), which efficiently delivers fusion proteins into the cell cytoplasm by unspecific binding to cell surface. We compared the adjuvanticity and toxicity of Tat PTD-CTA1-Tat PTD (TCTA1T) with those of CT. Our results indicate that intranasal (i.n.) delivery of ovalbumin (OVA) with TCTA1T significantly augments the OVA-specific systemic and mucosal antibody responses to levels comparable to those seen with CT adjuvant. Moreover,in vivocytotoxic T lymphocyte activity elicited by TCTA1T was significantly higher than that elicited by a mutant TCTA1T (TmCTA1T) lacking ADP-ribosyltransferase function. In addition, coadministration of influenza M2 protein with TCTA1T conferred near complete protection against lethal influenza virus challenge. Importantly, TCTA1T, in contrast to CT, did not induce serum IgG antibody responses to itself and was shown to be nontoxic. These results suggest that TCTA1T may be a safe and effective adjuvant when given by mucosal routes.

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Single dose rVSVΔG-JUNVGP vaccine protects guinea pigs against lethal Junin virus challenge

npj Vaccines ◽

10.1038/s41541-021-00361-0 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Teresa E. Sorvillo ◽

Robert W. Cross ◽

Dylan M. Johnson ◽

Natalie S. Dobias ◽

Karla A. Fenton ◽

...

Keyword(s):

Guinea Pigs ◽

Neutralizing Antibodies ◽

Virus Disease ◽

Protective Efficacy ◽

The United States ◽

High Avidity ◽

Igg Antibody ◽

Junin Virus ◽

Virus Challenge ◽

Junín Virus

AbstractJunin virus (JUNV) is a pathogen of biodefense importance due to its potential for aerosol transmission and mortality rates reaching 30%. Currently, there are no JUNV vaccines licensed by the United States Food and Drug Administration (FDA) for at-risk individuals. A vaccine based on recombinant vesicular stomatitis virus (rVSV) has been effectively used to prevent Ebola virus disease in humans. Here, we evaluated the protective efficacy of a rVSV expressing the JUNV glycoprotein (rVSVΔG-JUNVGP) in a guinea pig model of lethal JUNV disease. Two groups of guinea pigs, one prime and one prime-boost, were vaccinated with rVSVΔG-JUNVGP; six control animals remained unvaccinated. Survival for prime and prime-boost vaccinated animals was 100% while the challenge virus was uniformly lethal in all control animals. Animals in both vaccine groups developed robust, high avidity IgG antibody titers post-vaccination as well as detectable neutralizing antibodies while control animals failed to develop detectable antibody responses. This study demonstrates for the first time that rVSV expressing the JUNV GP fully protects guinea pigs from lethal JUNV challenge with a single injection vaccine.

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Optimization of Non-Coding Regions Improves Protective Efficacy of an mRNA SARS-CoV-2 Vaccine in Nonhuman Primates

10.1101/2021.08.13.456316 ◽

2021 ◽

Author(s):

Makda Gebre ◽

Susanne Rauch ◽

Nicole Roth ◽

Jingyou Yu ◽

Abishek Chandrashekar ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Nonhuman Primates ◽

Protective Efficacy ◽

Neutralizing Antibody ◽

Antigen Expression ◽

Antibody Responses ◽

Partial Protection ◽

Viral Loads ◽

Coding Regions ◽

Cell Responses

The CVnCoV (CureVac) mRNA vaccine for SARS-CoV-2 has recently been evaluated in a phase 2b/3 efficacy trial in humans. CV2CoV is a second-generation mRNA vaccine with optimized non-coding regions and enhanced antigen expression. Here we report a head-to-head study of the immunogenicity and protective efficacy of CVnCoV and CV2CoV in nonhuman primates. We immunized 18 cynomolgus macaques with two doses of 12 ug of lipid nanoparticle formulated CVnCoV, CV2CoV, or sham (N=6/group). CV2CoV induced substantially higher binding and neutralizing antibodies, memory B cell responses, and T cell responses as compared with CVnCoV. CV2CoV also induced more potent neutralizing antibody responses against SARS-CoV-2 variants, including B.1.351 (beta), B.1.617.2 (delta), and C.37 (lambda). While CVnCoV provided partial protection against SARS-CoV-2 challenge, CV2CoV afforded robust protection with markedly lower viral loads in the upper and lower respiratory tract. Antibody responses correlated with protective efficacy. These data demonstrate that optimization of non-coding regions can greatly improve the immunogenicity and protective efficacy of an mRNA SARS-CoV-2 vaccine in nonhuman primates.

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Vaccination with SARS-CoV-2 variants of concern protects mice from challenge with wild-type virus

PLoS Biology ◽

10.1371/journal.pbio.3001384 ◽

2021 ◽

Vol 19 (12) ◽

pp. e3001384

Author(s):

Fatima Amanat ◽

Shirin Strohmeier ◽

Philip Meade ◽

Nicholas Dambrauskas ◽

Barbara Mühlemann ◽

...

Keyword(s):

Mouse Model ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Wild Type Virus ◽

Type Virus ◽

Wild Type ◽

Fold Reduction ◽

Reactive Antibody

Vaccines against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been highly efficient in protecting against Coronavirus Disease 2019 (COVID-19). However, the emergence of viral variants that are more transmissible and, in some cases, escape from neutralizing antibody responses has raised concerns. Here, we evaluated recombinant protein spike antigens derived from wild-type SARS-CoV-2 and from variants B.1.1.7, B.1.351, and P.1 for their immunogenicity and protective effect in vivo against challenge with wild-type SARS-CoV-2 in the mouse model. All proteins induced high neutralizing antibodies against the respective viruses but also induced high cross-neutralizing antibody responses. The decline in neutralizing titers between variants was moderate, with B.1.1.7-vaccinated animals having a maximum fold reduction of 4.8 against B.1.351 virus. P.1 induced the most cross-reactive antibody responses but was also the least immunogenic in terms of homologous neutralization titers. However, all antigens protected from challenge with wild-type SARS-CoV-2 in a mouse model.

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Selection of a Rare Neutralization-Resistant Variant following Passive Transfer of Convalescent Immune Plasma in Equine Infectious Anemia Virus-Challenged SCID Horses

Journal of Virology ◽

10.1128/jvi.00218-10 ◽

2010 ◽

Vol 84 (13) ◽

pp. 6536-6548 ◽

Cited By ~ 14

Author(s):

Sandra D. Taylor ◽

Steven R. Leib ◽

Susan Carpenter ◽

Robert H. Mealey

Keyword(s):

Neutralizing Antibodies ◽

Equine Infectious Anemia Virus ◽

Severe Combined Immunodeficiency ◽

Febrile Episode ◽

Clinical Disease ◽

Resistant Variant ◽

Homologous Virus ◽

Equine Infectious Anemia ◽

Anemia Virus

ABSTRACT Vaccines preventing HIV-1 infection will likely elicit antibodies that neutralize diverse strains. However, the capacity for lentiviruses to escape broadly neutralizing antibodies (NAbs) is not completely understood, nor is it known whether NAbs alone can control heterologous infection. Here, we determined that convalescent immune plasma from a horse persistently infected with equine infectious anemia virus (EIAV) neutralized homologous virus and several envelope variants containing heterologous principal neutralizing domains (PND). Plasma was infused into young horses (foals) affected with severe combined immunodeficiency (SCID), followed by challenge with a homologous EIAV stock. Treated SCID foals were protected against clinical disease, with complete prevention of infection occurring in one foal. In three SCID foals, a novel neutralization-resistant variant arose that was found to preexist at a low frequency in the challenge inoculum. In contrast, SCID foals infused with nonimmune plasma developed acute disease associated with high levels of the predominant challenge virus. Following transfer to an immunocompetent horse, the neutralization-resistant variant induced a single febrile episode and was subsequently controlled in the absence of type-specific NAb. Long-term control was associated with the presence of cytotoxic T lymphocytes (CTL). Our results demonstrate that immune plasma with neutralizing activity against heterologous PND variants can prevent lentivirus infection and clinical disease in the complete absence of T cells. Importantly, however, rare neutralization-resistant envelope variants can replicate in vivo under relatively broad selection pressure, highlighting the need for protective lentivirus vaccines to elicit NAb responses with increased breadth and potency and/or CTL that target conserved epitopes.

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