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Poultry Science Jun 2023An immunization experiment was conducted in specific pathogen-free chickens with the inactivated Newcastle disease virus (NDV) vaccine encapsulated in the...
An immunization experiment was conducted in specific pathogen-free chickens with the inactivated Newcastle disease virus (NDV) vaccine encapsulated in the poly-(lactic-co-glycolic) acid (PLGA) nanoparticles (NP) to evaluate its immunogenicity and protective efficacy. The NDV vaccine was prepared by inactivating one virulent Indian strain of NDV belonging to Genotype VII by using beta-propiolactone. PLGA nanoparticles encapsulating inactivated NDV were prepared by the solvent evaporation method. Scanning electron microscopy and zeta sizer analysis revealed that the (PLGA+NDV) NP were spherical, with an average size of 300 nm, having a zeta potential of -6 mV. The encapsulation efficiency and loading efficiency were 72% and 2.4%, respectively. On immunization trial in chicken, the (PLGA+NDV) NP induced significantly (P < 0.0001) higher levels of HI and IgY antibodies with the peak HI titer of 2 and higher expression of IL-4 mRNA. The consistency of higher antibody levels suggests slow and pulsatile release of the antigens from the (PLGA+NDV) NP. The nano-NDV vaccine also induced cell mediated immunity with higher expression of IFN-γ indicating strong Th1 mediated immune responses in contrast to the commercial oil adjuvanted inactivated NDV vaccine. Further, the (PLGA+NDV) NP afforded 100% protection against the virulent NDV challenge. Our results suggested that PLGA NP have adjuvant potential on induction of humoral as well as Th1 biased cell mediated immune responses and also enhanced protective efficacy of the inactivated NDV vaccine. This study provides an insight for development of PLGA NP based inactivated NDV vaccine using the same genotype circulating in the field as well as for other avian diseases at exigencies.
Topics: Animals; Newcastle disease virus; Newcastle Disease; Chickens; Vaccines, Inactivated; Glycols; Adjuvants, Immunologic; Immunity, Cellular; Nanoparticles; Viral Vaccines
PubMed: 37116285
DOI: 10.1016/j.psj.2023.102679 -
Emerging Microbes & Infections Dec 2021The unprecedented in recent history global COVID-19 pandemic urged the implementation of all existing vaccine platforms to ensure the availability of the vaccines...
The unprecedented in recent history global COVID-19 pandemic urged the implementation of all existing vaccine platforms to ensure the availability of the vaccines against COVID-19 to every country in the world. Despite the multitude of high-quality papers describing clinical trials of different vaccine products, basic detailed data on general toxicity, reproductive toxicity, immunogenicity, protective efficacy and durability of immune response in animal models are scarce. Here, we developed a β-propiolactone-inactivated whole virion vaccine CoviVac and assessed its safety, protective efficacy, immunogenicity and stability of the immune response in rodents and non-human primates. The vaccine showed no signs of acute/chronic, reproductive, embryo- and fetotoxicity, or teratogenic effects, as well as no allergenic properties in studied animal species. The vaccine induced stable and robust humoral immune response both in form of specific anti-SARS-CoV-2 IgG and NAbs in mice, Syrian hamsters, and common marmosets. The NAb levels did not decrease significantly over the course of one year. The course of two immunizations protected Syrian hamsters from severe pneumonia upon intranasal challenge with the live virus. Robustness of the vaccine manufacturing process was demonstrated as well. These data encouraged further evaluation of CoviVac in clinical trials.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; COVID-19; COVID-19 Vaccines; Callithrix; Cricetinae; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Guinea Pigs; Humans; Immunity, Humoral; Immunogenicity, Vaccine; Immunoglobulin G; Male; Mesocricetus; Mice; Mice, Inbred BALB C; Rats; Rats, Wistar; SARS-CoV-2; Time Factors; Vaccines, Inactivated
PubMed: 34427172
DOI: 10.1080/22221751.2021.1971569 -
IScience Feb 2023Vaccines have relieved the public health burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and globally inactivated vaccines are most widely used....
Vaccines have relieved the public health burden of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and globally inactivated vaccines are most widely used. However, poor vaccination accessibility and waning immunity maintain the pandemic, driving emergence of variants. We developed an inactivated SARS-CoV-2 (I-SARS-CoV-2) vaccine based on a viral isolate with the Spike mutation D614G, produced in Vero cells in a scalable bioreactor, inactivated with β-propiolactone, purified by membrane-based steric exclusion chromatography, and adjuvanted with MF59-like adjuvant AddaVax. I-SARS-CoV-2 and a derived split vaccine induced persisting neutralizing antibodies in mice; moreover, lyophilized antigen was immunogenic. Following homologous challenge, I-SARS-CoV-2 immunized hamsters were protected against disease and lung pathology. In contrast with reports for widely used vaccines, hamster plasma similarly neutralized the homologous and the Delta (B.1.617.2) variant viruses, whereas the Omicron (B.1.1.529) variant was neutralized less efficiently. Applied bioprocessing approaches offer advantages regarding scalability and production, potentially benefitting worldwide vaccine coverage.
PubMed: 36644321
DOI: 10.1016/j.isci.2023.105949 -
Development of an Antigen Detection Kit Capable of Discriminating the Omicron Mutants of SARS-CoV-2.Vaccines Jan 2023Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the world, caused millions of deaths and a severe illness which poses a serious threat to...
INTRODUCTION
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread around the world, caused millions of deaths and a severe illness which poses a serious threat to human health.
OBJECTIVE
To develop an antigen detection kit that can identify Omicron novel coronavirus mutants.
METHODS
BALB/c mice were immunized with the nucleocapsid protein of SARS-CoV-2 Omicron mutant treated with β-propiolactone. After fusion of myeloma cells with immune cells, Elisa was used to screen the cell lines capable of producing monoclonal antibodies. The detection kit was prepared by colloidal gold immunochromatography. Finally, the sensitivity, specificity and anti-interference of the kit were evaluated by simulating positive samples.
RESULTS
The sensitivity of the SARS-CoV-2 antigen detection kit can reach 62.5 TCID/mL, and it has good inclusiveness for different SARS-CoV-2 strains. The kit had no cross-reaction with common respiratory pathogens, and its sensitivity was still not affected under the action of different concentrations of interferences, indicating that it had good specificity and stability.
CONCLUSION
In this study, monoclonal antibodies with high specificity to the N protein of the Omicron mutant strain were obtained by monoclonal antibody screening technology. Colloidal gold immunochromatography technology was used to prepare an antigen detection kit with high sensitivity to detect and identify the mutant Omicron strain.
PubMed: 36851181
DOI: 10.3390/vaccines11020303 -
Journal of Virological Methods Jan 2021Coronavirus disease 2019 (COVID-19) pandemic caused by infection with severe acute respiratory syndrome - coronavirus-2 (SARS-CoV-2) continues to affect many countries...
BACKGROUND
Coronavirus disease 2019 (COVID-19) pandemic caused by infection with severe acute respiratory syndrome - coronavirus-2 (SARS-CoV-2) continues to affect many countries and large populations. Serologic assays for antibody detection aid patient diagnosis and seroepidemiologic investigations.
METHODS
An indirect IgG ELISA was developed indigenously using β-propiolactone (BPL) inactivated SARS-CoV-2. This assay was used for screening 200 healthy donor sera collected prior to COVID-19 emergence (2017-2019), 185 serum/plasma samples of confirmed COVID-19 patients (n = 137) and 57 samples of viral RNA positive asymptomatic contacts (n = 51). The IgG response was studied in relation to duration and severity of illness.
RESULTS
The ELISA demonstrated 97 % specificity and IgG detection in >50 %, 80 %, 93.8 % and 100 % of the patients respectively during the first, second, third and fourth week of illness. IgG detection rate was higher in patients with severe disease (SD, 90.9 %) than those with mild disease (MD, 68.8 %) during the second week of illness (P = 0.027). IgG seropositivity among asymptomatic contacts was 64.7 %. IgG ELISA absorbance values were higher in SD than MD patients during the first 2 weeks of illness (P < 0.05). No significant difference was observed between the absorbance values of asymptomatic subjects and MD patients (P = 0.94).
CONCLUSION
The BPL inactivated virus-based ELISA could detect IgG antibodies early and in a significant proportion of COVID-19 patients suggesting its potential utility as a supplement to the currently used viral RNA detection tests in patient diagnosis and contact screening algorithms.
Topics: Antibodies, Viral; COVID-19; COVID-19 Serological Testing; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin G; Propiolactone; SARS-CoV-2; Sensitivity and Specificity; Seroepidemiologic Studies; Virus Inactivation
PubMed: 33126149
DOI: 10.1016/j.jviromet.2020.113996 -
Pathogens (Basel, Switzerland) May 2021The development of a safe and effective vaccine to protect against COVID-19 is a global priority due to the current high SARS-CoV-2 infection rate. Currently, there are...
The development of a safe and effective vaccine to protect against COVID-19 is a global priority due to the current high SARS-CoV-2 infection rate. Currently, there are over 160 SARS-CoV-2 vaccine candidates at the clinical or pre-clinical stages of development. Of these, there are only three whole-virus vaccine candidates produced using β-propiolactone or formalin inactivation. Here, we prepared a whole-virus SARS-CoV-2 vaccine (SARS-CoV-2 PsIV) using a novel psoralen inactivation method and evaluated its immunogenicity in mice using two different adjuvants, alum and Advax-2. We compared the immunogenicity of SARS-CoV-2 PsIV against SARS-CoV-2 DNA vaccines expressing either full-length or truncated spike proteins. We also compared the psoralen-inactivated vaccine against a DNA prime, psoralen-inactivated vaccine boost regimen. After two doses, the psoralen-inactivated vaccine, when administered with alum or Advax-2 adjuvants, generated a dose-dependent neutralizing antibody responses in mice. Overall, the pattern of cytokine ELISPOT responses to antigen-stimulation observed in this study indicates that SARS-CoV-2 PsIV with the alum adjuvant promotes a Th2-type response, while SARS-CoV-2 PsIV with the Advax-2 adjuvant promotes a Th1-type response.
PubMed: 34069575
DOI: 10.3390/pathogens10050626 -
Vaccines Mar 2023Vaccines are one of the efficient means available so far for preventing and controlling the infection rate of COVID-19. Several researchers have focused on the whole...
Vaccines are one of the efficient means available so far for preventing and controlling the infection rate of COVID-19. Several researchers have focused on the whole virus's (SARS-CoV-2) inactivated vaccines which are economically efficient to produce. In Pakistan, multiple variants of SARS-CoV-2 have been reported since the start of the pandemic in February 2020. Due to the continuous evolution of the virus and economic recessions, the present study was designed to develop an indigenous inactivated SARS-CoV-2 vaccine that might help not only to prevent the COVID-19 in Pakistan, it will also save the country's economic resources. The SARS-CoV-2 were isolated and characterized using the Vero-E6 cell culture system. The seed selection was carried out using cross-neutralization assay and phylogenetic analysis. The selected isolate of SARS-CoV-2 (hCoV-19/Pakistan/UHSPK3-UVAS268/2021) was inactivated using beta-propiolactone followed by vaccine formulation using Alum adjuvant, keeping the S protein concentration as 5 μg/dose. The vaccine efficacy was evaluated by in vivo immunogenicity testing in laboratory animals and in in vitro microneutralization test. The phylogenetic analysis revealed that all the SARS-CoV-2 isolates reported from Pakistan nested into different clades, representing multiple introductions of the virus into Pakistan. The antisera raised against various isolates from different waves in Pakistan showed a varied level of neutralization titers. However, the antisera produced against a variant (hCoV-19/Pakistan/UHSPK3-UVAS268/2021; fourth wave) efficiently neutralized (1:64-1:512) all the tested SARS-CoV-2 isolates. The inactivated whole virus vaccine of SARS-CoV-2 was safe and it also elicited a protective immune response in rabbits and rhesus macaques on the 35th-day post-vaccination. The activity of neutralizing antibodies of vaccinated animals was found at 1:256-1:1024 at 35 days post-vaccination, indicating the effectiveness of the double-dose regime of the indigenous SARS-CoV-2 vaccine.
PubMed: 36992191
DOI: 10.3390/vaccines11030607 -
Macromolecules Jun 2020We report here the synthesis of poly(4-ketovalerolactone) () via ring-opening transesterification polymerization (ROTEP) of the monomer 4-ketovalerolactone (, two steps...
We report here the synthesis of poly(4-ketovalerolactone) () via ring-opening transesterification polymerization (ROTEP) of the monomer 4-ketovalerolactone (, two steps from levulinic acid). The polymerization of proceeds to high equilibrium monomer conversion (up to 96% in the melt) to give the semicrystalline polyketoester with low dispersity. displays glass transition temperatures of 7 °C and two melting temperatures at 132 and 148 °C. This polyester can be chemically recycled through hydrolytic degradation. Under aqueous neutral or acidic conditions, the dominating pathway for polyester hydrolysis is through backbiting from the chain end. Under basic conditions, mid-chain cleavage, accelerated by the ketone carbonyl group in the backbone, promotes the hydrolysis of nearby backbone ester bonds. The final hydrolysis product is 5-hydroxylevulinic acid, the ring opened hydrolysis product of . was also observed to degrade under the action of a Brønsted acid to a bis-spirocyclic dilactone natural product altaicadispirolactone, which is a dimer of . This constitutes a rare example of a one-step synthesis of a secondary metabolite of non-trivial structure in which a polymer was the starting material and the sole source of matter. Analogous ROTEP of the isomeric 4-membered lactone 4-acetyl-β-propiolactone () was also explored, although this chemistry was not as well-behaved as the to polymerization.
PubMed: 33767514
DOI: 10.1021/acs.macromol.0c00787 -
Animals : An Open Access Journal From... Apr 2023This article describes the preparation of an inactivated vaccine from an attenuated strain of camelpox. The attenuated camelpox virus (CMLV) was grown in lamb kidney...
This article describes the preparation of an inactivated vaccine from an attenuated strain of camelpox. The attenuated camelpox virus (CMLV) was grown in lamb kidney cells and in Vero cells. CMLV was accumulated to a significantly higher ( ≤ 0.05) titer in lamb kidney cells (7.75 ± 0.08 log TCID/) than in Vero cells (4.00 ± 0.14 log TCID/). During virus inactivation, a concentration of 0.05% beta-propiolactone (BPL) completely inactivated the virus in 6 h at a temperature of 22 ± 1 °C, while a concentration of 0.2% formaldehyde inactivated the virus in 8 h. However, a viral antigen inactivated by BPL was used for vaccine preparation. The inactivated viral antigen was adsorbed with aluminum hydroxide gel, and as a result, an inactivated candidate vaccine was prepared. While the safety of the candidate vaccine was tested in camels and white mice, the protective efficacy of the vaccine was tested only in camels. In the safety evaluation of the inactivated vaccine, the vaccine was not observed to cause any adverse effects in mice and camels. During the immunogenicity study in camels, antibody formation started (0.2 ± 0.16 log2) at Day 21 post-vaccination (PV), and the antibody titer peaked (1.33 ± 0.21 log2) at Day 60 PV and decreased at Day 90 PV (0.50 ± 0.22 log2). Furthermore, no antibodies were detected in vaccinated camels from Days 180 to 365 PV. Camels that received vaccination and were subsequently exposed to wild-type virus evinced a healthy state despite lacking antibodies. In contrast, unvaccinated camels exhibited susceptibility to camelpox upon challenge.
PubMed: 37174551
DOI: 10.3390/ani13091513 -
International Journal of Infectious... Mar 2021We evaluated molecular-based point-of-care influenza virus detection systems in a laboratory prior to a field evaluation of on-site specimen testing.
BACKGROUND
We evaluated molecular-based point-of-care influenza virus detection systems in a laboratory prior to a field evaluation of on-site specimen testing.
METHODS
The performance characteristics of 1) insulated isothermal polymerase chain reaction (PCR) on a POCKIT™ device and 2) real-time reverse transcription-PCR (rRT-PCR) on a MyGo Mini™ device were evaluated using human clinical specimens, beta-propiolactone-inactivated influenza viruses, and RNA controls. The rRT-PCR carried out on a CXF-96™ real-time detection system was used as a gold standard for comparison.
RESULTS
Both systems demonstrated 100% sensitivity and specificity and test results were in 100% agreement with the gold standard. POCKIT™ only correctly identified influenza A (M gene) in clinical specimens due to the unavailability of typing and subtyping reagents for human influenza viruses, while MyGo Mini™ had either a one log higher or the same sensitivity in detecting influenza viruses in clinical specimens compared to the gold standard. For inactivated viruses and/or viral RNA, the analytic sensitivity of POCKIT™ was shown to be comparable to, or more sensitive, than the gold standard. The analytic sensitivity of MyGo Mini™ had mixed results depending on the types and subtypes of influenza viruses.
CONCLUSIONS
The performance of the two systems in a laboratory is promising and supports further evaluation in field settings.
Topics: Early Diagnosis; Humans; Influenza, Human; Laboratories; Laos; Orthomyxoviridae; Point-of-Care Systems; RNA, Viral; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 33359952
DOI: 10.1016/j.ijid.2020.12.059