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Voprosy Virusologii Sep 2020The only currently available live vaccine against yellow fever (YF) based on chicken embryos infected with an attenuated 17D strain of the YF virus is one of the most...
INTRODUCTION
The only currently available live vaccine against yellow fever (YF) based on chicken embryos infected with an attenuated 17D strain of the YF virus is one of the most effective vaccine preparations. However, the live vaccine is associated with "viscerotropic syndrome" (approximately 0.4 cases per 100 000 vaccinated). Therefore, the development and introduction of highly purified inactivated vaccine against YF is intended to ensure the maximum safety of vaccination against one of the most common human viral diseases.Goals and objectives. Development and evaluation of immunogenicity of the cultural inactivated vaccine against YF at the laboratory model level.
MATERIAL AND METHODS
Adaptation of 17D strain of YF virus to Vero cell culture, cultivation, removal of cellular DNA, inactivation with β-propiolactone, concentration, chromatographic purification, determination of protein and antigen of YF virus, assessment of immunogenicity in mice in parallel with commercial live vaccine.
RESULTS AND DISCUSSION
Immunogenicity: the determination of specific antibodies of class G (IgG) and virus neutralizing antibodies in the sera of immunized mice showed high level of antibodies exceeding that of immunized with commercial live vaccine. The optimal dose of antigen in the vaccine (total protein) was 50 μg/ml (5 μg/0.1 ml -dose and volume per 1 vaccination of mice). Thus, the laboratory version of cultural inactivated vaccine against YF is as effective (and even superior) as the commercial live vaccine.
CONCLUSION
Laboratory version of cultural inactivated vaccine against YF, which is not inferior in immunogenicity (in animal model) to commercial live vaccine, has been developed.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Antigens, Viral; Chlorocebus aethiops; Female; Humans; Mice; Vaccines, Attenuated; Vero Cells; Yellow Fever; Yellow Fever Vaccine; Yellow fever virus
PubMed: 33533224
DOI: 10.36233/0507-4088-2020-65-4-212-217 -
Vaccines Jan 2021Tilapia lake virus (TiLV) is a newly emerging pathogen responsible for high mortality and economic losses in the global tilapia industry. Currently, no antiviral therapy...
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 10, 10, and 10 50% tissue culture infectious dose (TCID)/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.
PubMed: 33503930
DOI: 10.3390/vaccines9020086 -
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 -
Viral Immunology Mar 2021Avian influenza viruses (AIVs) infect a wide range of hosts, including humans and many avian species. Efforts have been made to control this pathogen in chickens using...
Avian influenza viruses (AIVs) infect a wide range of hosts, including humans and many avian species. Efforts have been made to control this pathogen in chickens using vaccination programs, but that has been met with varying degrees of success. Therefore, identification of more efficacious vaccination strategies is warranted. This study was undertaken to investigate the potential effects of probiotics on the immunogenicity of a beta-propiolactone-whole inactivated virus (WIV) vaccine of H9N2 subtype adjuvanted with the Toll-like receptor-21 ligand, CpG oligodeoxynucleotides 2007 (CpG). Eighty-four 1-day-old White Leghorn layers were allocated into six groups. Two out of six groups received a mixture of probiotic spp. (PROB) biweekly from days 1 35 of age. Chickens were intramuscularly vaccinated with WIV either alone or adjuvanted with AddaVax™ (WIV+Add) or CpG (WIV+CpG), and one group received saline (phosphate-buffered saline). Primary and secondary vaccinations occurred at days 14 and 28 of age, respectively. The results revealed that the group that received probiotics and was vaccinated with CpG-adjuvanted WIV H9N2 vaccine had higher hemagglutination inhibition titers than the other treatment groups at days 14 and 21 postprimary vaccination. Probiotics did not induce higher IgM or IgY titers in chickens receiving the WIV vaccine only. Concerning their effect on cell-mediated immune responses, probiotics enhanced interferon-gamma (IFN-γ) gene expression and significantly increased secretion of IFN-γ protein by splenocytes in chickens vaccinated with CpG-adjuvanted WIV H9N2. Together, these findings suggest the use of probiotics to enhance the immunogenicity of CpG-adjuvanted WIV H9N2 vaccines. Additional studies are required to better understand the specific interactions between probiotics and the gut microbiota and different types of cells of the gastrointestinal tract to decipher the underlying mechanisms of how probiotics modulate immune responses to vaccines.
Topics: Animals; Antibodies, Viral; Chickens; Influenza A Virus, H9N2 Subtype; Influenza Vaccines; Influenza in Birds; Lactobacillus; Poultry Diseases; Probiotics; Vaccines, Inactivated
PubMed: 33236974
DOI: 10.1089/vim.2020.0209 -
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 -
Journal of Virological Methods Jan 2021Zika virus (ZIKV) infection remains a public health concern necessitating demand for long-term virus production for diagnostic assays and R&D activities. Inactivated...
Zika virus (ZIKV) infection remains a public health concern necessitating demand for long-term virus production for diagnostic assays and R&D activities. Inactivated virus constitutes an important component of the Trioplex rRT-PCR assay and serological IgM assay (MAC-ELISA). The aim of our study is to establish standard methods of ZIKV inactivation while maintaining antigenicity and RNA integrity. We tested viral supernatants by four different inactivation methods: 1. Heat inactivation at 56 °C and 60 °C; 2. Gamma-Irradiation; 3. Chemical inactivation by Beta-propiolactone (BPL) and 4. Fast-acting commercial disinfecting agents. Effectivity was measured by cytopathic effect (CPE) and plaque assay. RNA stability and antigenicity were measured by RT-PCR and MAC-ELISA, respectively. Results: Heat inactivation: Low titer samples, incubated at 56 °C for 2 h, showed neither CPE or plaques compared to high titer supernatants that required 2.5 h. Inactivation occurred at 60 °C for 60 min with all virus titers. Gamma irradiation: Samples irradiated at ≥3 Mrad for low virus concentrations and ≥5Mrad for high virus titer completely inactivated virus. Chemical Inactivation: Neither CPE nor plaques were observed with ≥0.045 % BPL inactivation of ZIKV. Disinfectant: Treatment of viral supernatants with Micro-Chem Plus™, inactivated virus in 2 min, whereas, Ethanol (70 %) and STERIS Coverage® Spray TB inactivated the virus in 5 min.
Topics: Disinfection; Humans; Indicators and Reagents; Virus Inactivation; Zika Virus; Zika Virus Infection
PubMed: 33098957
DOI: 10.1016/j.jviromet.2020.114004 -
Virology Journal Oct 2020Transmissible gastroenteritis virus (TGEV) causes enteric infection in piglets, characterized by vomiting, severe diarrhea and dehydration, and the mortality in suckling...
BACKGROUND
Transmissible gastroenteritis virus (TGEV) causes enteric infection in piglets, characterized by vomiting, severe diarrhea and dehydration, and the mortality in suckling piglets is often high up to 100%. Vaccination is an effective measure to control the disease caused by TGEV.
METHODS
In this study, cell-cultured TGEV HN-2012 strain was inactivated by formaldehyde (FA), β-propiolactone (BPL) or binaryethylenimine (BEI), respectively. Then the inactivated TGEV vaccine was prepared with freund's adjuvant, and the immunization effects were evaluated in mice. The TGEV-specific IgG level was detected by ELISA. The positive rates of CD4, CD8, CD4IFN-γ, CD4IL-4 T lymphocytes were detected by flow cytometry assay. Lymphocyte proliferation assay and gross pathology and histopathology examination were also performed to assess the three different inactivating reagents in formulating TGEV vaccine.
RESULTS
The results showed that the TGEV-specific IgG level in FA group (n = 17) was earlier and stronger, while the BEI group produced much longer-term IgG level. The lymphocyte proliferation test demonstrated that the BEI group had a stronger ability to induce spleen lymphocyte proliferation. The positive rates of CD4 and CD8 T lymphocyte subsets of peripheral blood lymphocyte in BEI group was higher than that in FA group and BPL groups by flow cytometry assay. The positive rate of CD4IFN-γ T lymphocyte subset was the highest in the BPL group, and the positive rate of CD4IL-4 T lymphocyte subset was the highest in the FA group. There were no obvious pathological changes in the vaccinated mice and the control group after the macroscopic and histopathological examination.
CONCLUSIONS
These results indicated that all the three experimental groups could induce cellular and humoral immunity, and the FA group had the best humoral immunity effect, while the BEI group showed its excellent cellular immunity effect.
Topics: Animals; Antibodies, Viral; Female; Gastroenteritis, Transmissible, of Swine; Immunity, Cellular; Immunity, Humoral; Immunoglobulin G; Indicators and Reagents; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Swine; T-Lymphocytes; Transmissible gastroenteritis virus; Vaccines, Inactivated; Viral Vaccines; Virus Inactivation
PubMed: 33097081
DOI: 10.1186/s12985-020-01433-8 -
Structure (London, England : 1993) Nov 2020The ongoing global pandemic of coronavirus disease 2019 (COVID-19) resulted from the outbreak of SARS-CoV-2 in December 2019. Currently, multiple efforts are being made...
The ongoing global pandemic of coronavirus disease 2019 (COVID-19) resulted from the outbreak of SARS-CoV-2 in December 2019. Currently, multiple efforts are being made to rapidly develop vaccines and treatments to fight COVID-19. Current vaccine candidates use inactivated SARS-CoV-2 viruses; therefore, it is important to understand the architecture of inactivated SARS-CoV-2. We have genetically and structurally characterized β-propiolactone-inactivated viruses from a propagated and purified clinical strain of SARS-CoV-2. We observed that the virus particles are roughly spherical or moderately pleiomorphic. Although a small fraction of prefusion spikes are found, most spikes appear nail shaped, thus resembling a postfusion state, where the S1 protein of the spike has disassociated from S2. Cryoelectron tomography and subtomogram averaging of these spikes yielded a density map that closely matches the overall structure of the SARS-CoV postfusion spike and its corresponding glycosylation site. Our findings have major implications for SARS-CoV-2 vaccine design, especially those using inactivated viruses.
Topics: Animals; Betacoronavirus; COVID-19 Vaccines; Chlorocebus aethiops; Coronavirus Infections; Cryoelectron Microscopy; Disinfectants; Electron Microscope Tomography; Humans; Propiolactone; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Vaccines, Inactivated; Vero Cells; Viral Vaccines; Virion
PubMed: 33058760
DOI: 10.1016/j.str.2020.10.001 -
Journal of the American Society For... Nov 2020Synthetic polymers occupy a unique place in the field of ion mobility mass spectrometry (IMS-MS). Indeed, due to their intrinsic dispersity, they have the asset to offer...
Synthetic polymers occupy a unique place in the field of ion mobility mass spectrometry (IMS-MS). Indeed, due to their intrinsic dispersity, they have the asset to offer a broad range of homologous ions with different lengths that can be detected in several charge states. In addition, the gas-phase structure of polymer ions mostly depends on their ability to screen the adducted charges. Several works dealing with linear, cyclic, and star-shaped polymers have already shown that the gas-phase structure of polymer ions heavily relies on the polymer architecture, i.e., the primary structure. In the present work, we move a step further by evaluating whether a relationship exists between the primary and secondary structures of synthetic homo and copolymers. The IMS-MS experiments will be further complemented by MD simulations. To highlight the effectiveness of IMS separation, we selected isomeric homo and copolymers made of lactide (LA) and propiolactone (PL) units. In this way, the mass analysis becomes useless since isomeric comonomer sequences can coexist for any given chain length. An UPLC method was implemented in the workflow to successfully separate all PL-LA comonomer sequences before infusion in the IMS-MS instrument. The analysis of doubly charged copolymers showed that the comonomer sequence has an impact on the IMS response. However, this only holds for copolymer ions with precise sizes and charge states, and this is therefore not a rule of thumb.
PubMed: 33044069
DOI: 10.1021/jasms.0c00352 -
Archives of Medical Research Jan 2021The Coronavirus disease 2019 (COVID-19) pandemic has spread to almost all nooks and corners of the world. There are numerous potential approaches to pharmacologically... (Review)
Review
The Coronavirus disease 2019 (COVID-19) pandemic has spread to almost all nooks and corners of the world. There are numerous potential approaches to pharmacologically fight COVID-19: small-molecule drugs, interferon therapies, vaccines, oligonucleotides, peptides, and monoclonal antibodies. Medications are being developed to target the spike, membrane, nucleocapsid or envelope proteins. The spike protein is also a critical target for vaccine development. Immunoinformatic approaches are being used for the identification of B cell and cytotoxic T lymphocyte (CTL) epitopes in the SARS-CoV-2 spike protein. Different vaccine vectors are also being developed. Chemical and physical methods such as formaldehyde, UV light or β-propiolactone are being deployed for the preparation of inactivated virus vaccine. Currently, there are many vaccines undergoing clinical trials. Even though mRNA and DNA vaccines are being designed and moved into clinical trials, these types of vaccines are yet to be approved by regulatory bodies for human use. This review focuses on the drugs and vaccines being developed against the COVID-19.
Topics: COVID-19; COVID-19 Vaccines; Drug Development; Epitopes, T-Lymphocyte; Humans; SARS-CoV-2; Spike Glycoprotein, Coronavirus
PubMed: 32950264
DOI: 10.1016/j.arcmed.2020.09.010