Development of the Inactivated QazCovid-in Vaccine: Protective Efficacy of the Vaccine in Syrian Hamsters

In March 2020, the first cases of the human coronavirus disease COVID-19 were registered in Kazakhstan. We isolated the SARS-CoV-2 virus from clinical materials from some of these patients. Subsequently, a whole virion inactivated candidate vaccine, QazCovid-in, was developed based on this virus. To develop the vaccine, a virus grown in Vero cell culture was used, which was inactivated with formaldehyde, purified, concentrated, sterilized by filtration, and then adsorbed on aluminum hydroxide gel particles. The formula virus and adjuvant in buffer saline solution were used as the vaccine. The safety and protective effectiveness of the developed vaccine were studied in Syrian hamsters. The results of the studies showed the absolute safety of the candidate vaccine in the Syrian hamsters. When studying the protective effectiveness, the developed vaccine with an immunizing dose of 5 μg/dose specific antigen protected animals from a wild homologous virus at a dose of 104.5 TCID50/mL. The candidate vaccine induced the formation of virus-neutralizing antibodies in vaccinated hamsters at titers of 3.3 ± 1.45 log2 to 7.25 ± 0.78 log2, and these antibodies were retained for 6 months (observation period) for the indicated titers. No viral replication was detected in vaccinated hamsters, protected against the development of acute pneumonia, and ensured 100% survival of the animals. Further, no replicative virus was isolated from the lungs of vaccinated animals. However, a virulent virus was isolated from the lungs of unvaccinated animals at relatively high titers, reaching 4.5 ± 0.7 log TCID50/mL. After challenge infection, 100% of unvaccinated hamsters showed clinical symptoms (stress state, passivity, tousled coat, decreased body temperature, and body weight, and the development of acute pneumonia), with 25 ± 5% dying. These findings pave the way for testing the candidate vaccine in clinical human trials.

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Development Of The Inactivated QazCovid-In Vaccine: Protective Efficacy Of The Vaccine In Syrian Hamsters

10.1101/2021.07.13.452175 ◽

2021 ◽

Author(s):

Kuandyk Zhugunissov ◽

Kunsulu Zakarya ◽

Berik Khairullin ◽

Mukhit Orynbayev ◽

Yergali Abduraimov ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Protective Efficacy ◽

Specific Antigen ◽

Clinical Signs ◽

The Body ◽

Candidate Vaccine ◽

Syrian Hamsters ◽

Acute Pneumonia ◽

Virulent Virus ◽

Protective Effectiveness

In March 2020, the first cases of human coronavirus infection COVID-19 were registered in Kazakhstan. We isolated the SARS-CoV-2 virus from the clinical material from the patients. Subsequently, a whole virion inactivated candidate vaccine, QazCovid-in, was developed based on this virus. To obtain the vaccine, a virus grown in Vero cell culture was used, which was inactivated with formaldehyde, purified, concentrated, sterilized by filtration, and then sorbed on aluminum hydroxide gel particles. The formula virus and adjuvant in buffer saline solution was used as a vaccine. The safety and protective effectiveness of the developed vaccine was studied on Syrian hamsters. The results of the studies showed the absolute safety of the candidate vaccine on the Syrian hamsters. When studying the protective effectiveness, the developed vaccine with an immunizing dose of 5 mcg/dose of a specific antigen protected animals from wild virus at a dose of 104.5 TCID50/ml. The candidate vaccine formed virus-neutralizing antibodies in vaccinated hamsters in titers from 3.3 ± 1.45 log2 to 7.25 ± 0.78 log2, which were retained for 6 months (observation period) in the indicated titers. The candidate vaccine suppressed the replication of the wild virus in the body of vaccinated hamsters, protected against the development of acute pneumonia and ensured 100% survival of the animals. At the same time, no replicative virus was isolated from the lungs of vaccinated animals. At the same time, a virulent virus was isolated from the lungs of unvaccinated animals in relatively high titers, reaching 4.5 ± 0.7 lg TCID50/ml. After challenge infection, 100% of unvaccinated hamsters became ill with clinical signs (stress state, passivity, tousled coat, decreased body temperature and body weight, and the development of acute pneumonia), of which 25 ± 5% were fatal. The findings paved the way for testing the candidate vaccine in humans in clinical trials.

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Protective efficacy of a SARS-CoV-2 DNA vaccine in wild-type and immunosuppressed Syrian hamsters

npj Vaccines ◽

10.1038/s41541-020-00279-z ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Rebecca L. Brocato ◽

Steven A. Kwilas ◽

Robert K. Kim ◽

Xiankun Zeng ◽

Lucia M. Principe ◽

...

Keyword(s):

Dna Vaccine ◽

Neutralizing Antibodies ◽

Protective Efficacy ◽

Phase 1 ◽

Severe Disease ◽

Disease Model ◽

Wild Type ◽

Jet Injection ◽

Syrian Hamsters ◽

Dna Targeting

AbstractA worldwide effort to counter the COVID-19 pandemic has resulted in hundreds of candidate vaccines moving through various stages of research and development, including several vaccines in phase 1, 2 and 3 clinical trials. A relatively small number of these vaccines have been evaluated in SARS-CoV-2 disease models, and fewer in a severe disease model. Here, a SARS-CoV-2 DNA targeting the spike protein and delivered by jet injection, nCoV-S(JET), elicited neutralizing antibodies in hamsters and was protective in both wild-type and transiently immunosuppressed hamster models. This study highlights the DNA vaccine, nCoV-S(JET), we developed has a great potential to move to next stage of preclinical studies, and it also demonstrates that the transiently-immunosuppressed Syrian hamsters, which recapitulate severe and prolonged COVID-19 disease, can be used for preclinical evaluation of the protective efficacy of spike-based COVID-19 vaccines.

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Protective efficacy of a SARS-CoV-2 DNA Vaccine in wild-type and immunosuppressed Syrian hamsters

10.1101/2020.11.10.376905 ◽

2020 ◽

Author(s):

Rebecca L. Brocato ◽

Steven A. Kwilas ◽

Robert K. Kim ◽

Xiankun Zeng ◽

Lucia M. Principe ◽

...

Keyword(s):

Dna Vaccine ◽

Neutralizing Antibodies ◽

Protective Efficacy ◽

Phase 1 ◽

Severe Disease ◽

Disease Model ◽

Wild Type ◽

Jet Injection ◽

Syrian Hamsters ◽

Dna Targeting

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

Frontiers in Immunology ◽

10.3389/fimmu.2021.747774 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fan Zhou ◽

Lena Hansen ◽

Gabriel Pedersen ◽

Gunnveig Grødeland ◽

Rebecca Cox

Keyword(s):

Neutralizing Antibodies ◽

Protective Efficacy ◽

Antibody Responses ◽

Virus Challenge ◽

Adjuvanted Vaccine ◽

Domain Specific ◽

Homologous Virus ◽

Human Sera ◽

H5n1 Vaccine

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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Neutralizing Antibodies Elicited by a Novel Detoxified Pneumolysin Derivative, PlyD1, Provide Protection against Both Pneumococcal Infection and Lung Injury

Infection and Immunity ◽

10.1128/iai.06348-11 ◽

2012 ◽

Vol 80 (6) ◽

pp. 2212-2220 ◽

Cited By ~ 38

Author(s):

Danielle Salha ◽

Jason Szeto ◽

Lisa Myers ◽

Carol Claus ◽

Anthony Sheung ◽

...

Keyword(s):

Lung Injury ◽

Neutralizing Antibodies ◽

Pneumococcal Pneumonia ◽

Protective Efficacy ◽

Pneumococcal Infection ◽

Polyclonal Antiserum ◽

Candidate Vaccine ◽

Vaccine Antigen ◽

Lung Lesions

ABSTRACTStreptococcus pneumoniaepneumolysin (PLY) is a virulence factor that causes toxic effects contributing to pneumococcal pneumonia. To date, deriving a PLY candidate vaccine with the appropriate detoxification and immune profile has been challenging. A pneumolysin protein that is appropriately detoxified and that retains its immunogenicity is a desirable vaccine candidate. In this study, we assessed the protective efficacy of our novel PlyD1 detoxified PLY variant and investigated its underlying mechanism of protection. Results have shown that PlyD1 immunization protected mice against lethal intranasal (i.n.) challenge with pneumococci and lung injury mediated by PLY challenge. Protection was associated with PlyD1-specific IgG titers andin vitroneutralization titers. Pretreatment of PLY with PlyD1-specific rat polyclonal antiserum prior to i.n. delivery of toxin reduced PLY-mediated lung lesions, interleukin-6 (IL-6) production, and neutrophil infiltration into lungs, indicating that protection from lung lesions induced by PLY is antibody mediated. Preincubation of PLY with a neutralizing monoclonal PLY antibody also specifically reduced the cytotoxic effects of PLY after i.n. inoculation in comparison to nonneutralizing monoclonal antibodies. These results indicate that the induction of neutralizing antibodies against PLY can contribute to protection against bacterial pneumonia by preventing the development of PLY-induced lung lesions and inflammation. Our detoxified PlyD1 antigen elicits such PLY neutralizing antibodies, thus serving as a candidate vaccine antigen for the prevention of pneumococcal pneumonia.

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Protective Efficacy Induced by Recombinant Clostridium difficile Toxin Fragments

Infection and Immunity ◽

10.1128/iai.01341-12 ◽

2013 ◽

Vol 81 (8) ◽

pp. 2851-2860 ◽

Cited By ~ 30

Author(s):

Rosanna Leuzzi ◽

Janice Spencer ◽

Anthony Buckley ◽

Cecilia Brettoni ◽

Manuele Martinelli ◽

...

Keyword(s):

Clostridium Difficile ◽

Neutralizing Antibodies ◽

Clinical Symptoms ◽

Protective Efficacy ◽

Toxin Production ◽

Gut Contents ◽

Hamster Model ◽

Content Type ◽

High Concentrations ◽

Recombinant Polypeptides

ABSTRACTClostridium difficileis a spore-forming bacterium that can reside in animals and humans.C. difficileinfection causes a variety of clinical symptoms, ranging from diarrhea to fulminant colitis. Disease is mediated by TcdA and TcdB, two large enterotoxins released byC. difficileduring colonization of the gut. In this study, we evaluated the ability of recombinant toxin fragments to induce neutralizing antibodies in mice. The protective efficacies of the most promising candidates were then evaluated in a hamster model of disease. While limited protection was observed with some combinations, coadministration of a cell binding domain fragment of TcdA (TcdA-B1) and the glucosyltransferase moiety of TcdB (TcdB-GT) induced systemic IgGs which neutralized both toxins and protected vaccinated animals from death following challenge with two strains ofC. difficile. Further characterization revealed that despite high concentrations of toxin in the gut lumens of vaccinated animals during the acute phase of the disease, pathological damage was minimized. Assessment of gut contents revealed the presence of TcdA and TcdB antibodies, suggesting that systemic vaccination with this pair of recombinant polypeptides can limit the disease caused by toxin production duringC. difficileinfection.

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Development of a Viral-Like Particle Candidate Vaccine Against Novel Variant Infectious Bursal Disease Virus

Vaccines ◽

10.3390/vaccines9020142 ◽

2021 ◽

Vol 9 (2) ◽

pp. 142

Author(s):

Yulong Wang ◽

Nan Jiang ◽

Linjin Fan ◽

Li Gao ◽

Kai Li ◽

...

Keyword(s):

Disease Virus ◽

Infectious Bursal Disease Virus ◽

Protective Efficacy ◽

Expression System ◽

Size Exclusion ◽

Candidate Vaccine ◽

Infectious Bursal Disease ◽

Immune Protection ◽

Bursal Disease ◽

Novel Variant

Infectious bursal disease (IBD), an immunosuppressive disease of young chickens, is caused by infectious bursal disease virus (IBDV). Novel variant IBDV (nVarIBDV), a virus that can evade immune protection against very virulent IBDV (vvIBDV), is becoming a threat to the poultry industry. Therefore, nVarIBDV-specific vaccine is much needed for nVarIBDV control. In this study, the VP2 protein of SHG19 (a representative strain of nVarIBDV) was successfully expressed using an Escherichia coli expression system and further purified via ammonium sulfate precipitation and size-exclusion chromatography. The purified protein SHG19-VP2-466 could self-assemble into 25-nm virus-like particle (VLP). Subsequently, the immunogenicity and protective effect of the SHG19-VLP vaccine were evaluated using animal experiments, which indicated that the SHG19-VLP vaccine elicited neutralization antibodies and provided 100% protection against the nVarIBDV. Furthermore, the protective efficacy of the SHG19-VLP vaccine against the vvIBDV was evaluated. Although the SHG19-VLP vaccine induced a comparatively lower vvIBDV-specific neutralization antibody titer, it provided good protection against the lethal vvIBDV. In summary, the SHG19-VLP candidate vaccine could provide complete immune protection against the homologous nVarIBDV as well as the heterologous vvIBDV. This study is of significance to the comprehensive prevention and control of the recent atypical IBD epidemic.

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Concentrations of canine prostate specific esterase, CPSE, at baseline are associated with the relative size of the prostate at three-year follow-up

BMC Veterinary Research ◽

10.1186/s12917-021-02874-1 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Bodil S. Holst ◽

Sofia Carlin ◽

Virginie Fouriez-Lablée ◽

Sofia Hanås ◽

Sofie Ödling ◽

...

Keyword(s):

Clinical Symptoms ◽

Specific Antigen ◽

Relative Size ◽

Clinical Signs ◽

Serum Concentrations ◽

Prostatic Disease ◽

Follow Up Study ◽

Prostate Size ◽

Prostate Growth

Abstract Background Enlargement of the prostate is associated with prostatic diseases in dogs, and an estimation of prostatic size is a central part in the diagnostic workup. Ultrasonography is often the method of choice, but biomarkers constitute an alternative. Canine prostate specific esterase (CPSE) shares many characteristics with human prostate specific antigen (PSA) and is related to prostate size. In men with clinical symptoms of prostatic disease, PSA concentrations are related to prostate growth. The aims of the present follow-up study were to evaluate if the concentration of CPSE is associated with future growth of the prostate, and if analysis of a panel of 16 steroids gives further information on prostatic growth. Owners of dogs included in a previous study were 3 years later contacted for a follow-up study that included an interview and a clinical examination. The prostate was examined by ultrasonography. Serum concentrations of CPSE were measured, as was a panel of steroids. Results Of the 79 dogs included at baseline, owners of 77 dogs (97%) were reached for an interview, and 22 were available for a follow-up examination. Six of the 79 dogs had clinical signs of prostatic disease at baseline, and eight of the remaining 73 dogs (11%) developed clinical signs between baseline and follow-up, information was lacking for two dogs. Development of clinical signs was significantly more common in dogs with a relative prostate size of ≥2.5 at baseline (n = 20) than in dogs with smaller prostates (n = 51). Serum concentrations of CPSE at baseline were not associated with the change in prostatic size between baseline and follow-up. Serum concentrations of CPSE at baseline and at follow-up were positively associated with the relative prostatic size (Srel) at follow-up. Concentrations of corticosterone (P = 0.024), and the class corticosteroids (P = 0.0035) were positively associated with the difference in Srel between baseline and follow-up. Conclusions The results support the use of CPSE for estimating present and future prostatic size in dogs ≥4 years, and the clinical usefulness of prostatic size for predicting development of clinical signs of prostatic disease in the dog. The association between corticosteroids and prostate growth warrants further investigation.

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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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Structural and molecular basis for foot-and-mouth disease virus neutralization by two potent protective antibodies

10.1101/2020.12.31.424923 ◽

2021 ◽

Author(s):

Hu Dong ◽

Pan Liu ◽

Manyuan Bai ◽

Kang Wang ◽

Rui Feng ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Protective Efficacy ◽

Foot And Mouth Disease ◽

Therapeutic Benefit ◽

Mouth Disease ◽

Economic Losses ◽

Viral Particles ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Protective Antibodies

Outbreaks of Foot-and-mouth disease (FMD) caused by FMD virus result in significant economic losses. Vaccination is helpful, but the benefits are diminished with antigenic diversity within serotypes, instability of the immunogen and inability to confer protection for long durations. Here we have further dissected the mechanisms underpinning the protective efficacy of two previously reported neutralizing antibodies (NAbs), M8 and M170. The atomic details of the epitopes of M8 and M170 unveiled suggest that protection is conferred by disrupting the virus-receptor interactions. Consequently, administration of these NAbs conferred prophylactic and therapeutic benefit in guinea pigs, raising the possibility of administering NAbs before or during vaccination to confer immediate protection; well before the bolstering of the immune response by the vaccine. Differences in the residues and the conformation of elements making up the epitopes explain the differences in specificities of M8 and M170. An ability to bind 146S viral particles specifically, but not 12S degraded components, highlights a likely role for M170 in the quality control of vaccines.

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