scholarly journals Effect of the Route of Administration of the Vaccinia Virus Strain LIVP to Mice on Its Virulence and Immunogenicity

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 795
Author(s):  
Sergei N. Shchelkunov ◽  
Stanislav N. Yakubitskiy ◽  
Alexander A. Sergeev ◽  
Alexei S. Kabanov ◽  
Tatiana V. Bauer ◽  
...  

The mass smallpox vaccination campaign has played a crucial role in smallpox eradication. Various strains of the vaccinia virus (VACV) were used as a live smallpox vaccine in different countries, their origin being unknown in most cases. The VACV strains differ in terms of pathogenicity exhibited upon inoculation of laboratory animals and reactogenicity exhibited upon vaccination of humans. Therefore, each generated strain or clonal variant of VACV needs to be thoroughly studied in in vivo systems. The clonal variant 14 of LIVP strain (LIVP-14) was the study object in this work. A comparative analysis of the virulence and immunogenicity of LIVP-14 inoculated intranasally (i.n.), intradermally (i.d.), or subcutaneously (s.c.) to BALB/c mice at doses of 108, 107, and 106 pfu was carried out. Adult mice exhibited the highest sensitivity to the i.n. administered LIVP-14 strain, although the infection was not lethal. The i.n. inoculated LIVP-14 replicated efficiently in the lungs. Furthermore, this virus was accumulated in the brain at relatively high concentrations. Significantly lower levels of LIVP-14 were detected in the liver, kidneys, and spleen of experimental animals. No clinical manifestations of the disease were observed after i.d. or s.c. injection of LIVP-14 to mice. After s.c. inoculation, the virus was detected only at the injection site, while it could disseminate to the liver and lungs when delivered via i.d. administration. A comparative analysis of the production of virus-specific antibodies by ELISA and PRNT revealed that the highest level of antibodies was induced in i.n. inoculated mice; a lower level of antibodies was observed after i.d. administration of the virus and the lowest level after s.c. injection. Even at the lowest studied dose (106 pfu), i.n. or i.d. administered LIVP-14 completely protected mice against infection with the cowpox virus at the lethal dose. Our findings imply that, according to the ratio between such characteristics as pathogenicity/immunogenicity/protectivity, i.d. injection is the optimal method of inoculation with the VACV LIVP-14 strain to ensure the safe formation of immune defense after vaccination against orthopoxviral infections.

Author(s):  
E. K. Rakhmatullin ◽  
O. D. Sklyarov

Preclinical study of the drugs toxicity was analysed it allows predicting the safety of veterinary drugs in laboratory animals. The fundamental normative instruments in the field of preclinical study of drugs for veterinary medicine and animal husbandry are Order of the Ministry of Agriculture of the Russian Federation dated 06.03.2018 N 101 and GOST 33044-2014 Principles of Good Laboratory Practice. An important indicator of the preclinical study of the veterinary drugs is the determination (calculation) of median lethal dose value (lethal dose for half of the animals tested) or concentration (LD50 or LC50). Existing methods for determining this indicator make it possible at the initial study stage to determine the degree and class the drug of toxicity. Studying the symptoms of intoxication in the analysis of pharmacological substances one obtains significant information about the nature of the action of the future drug. The clinical manifestations of intoxication with damage to various organ systems are presented. As criteria for assessing the toxic effects of veterinary drugs it is recommended to determine LD50, cumulation coefficient, latitude index of therapeutic effects, dose level of toxic effects in the experiment which allows predicting the nature and degree of toxic effects of the drug even at the stage of preclinical veterinary drugs study.


Author(s):  
S. Shchelkunov ◽  
A. Sergeev ◽  
A. Kabanov ◽  
S. Yakubitskyi ◽  
T. Bauer ◽  
...  

Vaccinia virus had played a key role in the global smallpox eradication. However, in case of mass vaccination with various vaccinia virus strains severe side effects were revealed sometimes ending up with lethal outcomes, especially in immunocompromised humans. Hence, the World Health Organization recommended to cancel smallpox vaccination after declaring in 1980 about smallpox eradication. Over last 40 years, human population virtually lost immunity not only against smallpox, but also against other zoonotic orthopoxvirus infections, such as monkeypox, cowpox, buffalopox, and camel pox. All of them pose an represent increasing threat to human health and heighten a risk of emerging highly contagious viruses due to natural evolution of previous zoonotic orthopoxviruses. In order to prevent development of small outbreaks into spreading epidemics and, thus, to decrease a risk of emergence due to natural evolution of highly pathogenic for humans orthopoxviruses, efforts should be applied to develop safe new generation live vaccines based on vaccinia virus with target virulence genes inactivation. These strains should be examined in laboratory animal models inoculated via different routes. Currently, vaccinia virus often becomes attenuated to create live recombinant vaccines due to inserting target DNA sequences into the virus virulence genes resulting in their inactivation. Vaccinia virus strain LIVP used in the Russian Federation as smallpox vaccine as well as derivative attenuated variant LIVP-GFP created by using genetic engineering methods with inactivating its thymidine kinase gene were examined.Such viruses were intracerebrally inoculated into suckling mice at doses of 101 or 102 PFU/animal for neurovirulence assessment. Adult mice were infected intranasally, subcutaneously or intradermally at doses of 107 or 108 PFU/animal and clinical manifestations were analyzed for 14 days. On 28 day after the onset, blood serum samples were collected from individual mice to measure virus specific antibody level by using ELISA. It was shown that recombinant vaccinia virus strain LIVP-GFP displayed markedly lowered neurovirulence and pathogenicity for mice as compared to parental LIVP. Finally, intradermal route turned out to demonstrate the most safe and effective profile for immunization with both examined vaccinia virus strains.


Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1780
Author(s):  
Onur Kaynarcalidan ◽  
Sara Moreno Mascaraque ◽  
Ingo Drexler

Various vaccinia virus (VACV) strains were applied during the smallpox vaccination campaign to eradicate the variola virus worldwide. After the eradication of smallpox, VACV gained popularity as a viral vector thanks to increasing innovations in genetic engineering and vaccine technology. Some VACV strains have been extensively used to develop vaccine candidates against various diseases. Modified vaccinia virus Ankara (MVA) is a VACV vaccine strain that offers several advantages for the development of recombinant vaccine candidates. In addition to various host-restriction genes, MVA lacks several immunomodulatory genes of which some have proven to be quite efficient in skewing the immune response in an unfavorable way to control infection in the host. Studies to manipulate these genes aim to optimize the immunogenicity and safety of MVA-based viral vector vaccine candidates. Here we summarize the history and further work with VACV as a vaccine and present in detail the genetic manipulations within the MVA genome to improve its immunogenicity and safety as a viral vector vaccine.


mSphere ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Christina L. Hutson ◽  
Ashley V. Kondas ◽  
Mathew R. Mauldin ◽  
Jeffrey B. Doty ◽  
Irma M. Grossi ◽  
...  

ABSTRACT Smallpox, caused by Variola virus (VARV), was eradicated in 1980; however, VARV bioterrorist threats still exist, necessitating readily available therapeutics. Current preparedness activities recognize the importance of oral antivirals and recommend therapeutics with different mechanisms of action. Monkeypox virus (MPXV) is closely related to VARV, causing a highly similar clinical human disease, and can be used as a surrogate for smallpox antiviral testing. The prairie dog MPXV model has been characterized and used to study the efficacy of antipoxvirus therapeutics, including recently approved TPOXX (tecovirimat). Brincidofovir (BCV; CMX001) has shown antiviral activity against double-stranded DNA viruses, including poxviruses. To determine the exposure of BCV following oral administration to prairie dogs, a pharmacokinetics (PK) study was performed. Analysis of BCV plasma concentrations indicated variability, conceivably due to the outbred nature of the animals. To determine BCV efficacy in the MPXV prairie dog model, groups of animals were intranasally challenged with 9 × 105 plaque-forming units (PFU; 90% lethal dose [LD90]) of MPXV on inoculation day 0 (ID0). Animals were divided into groups based on the first day of BCV treatment relative to inoculation day (ID–1, ID0, or ID1). A trend in efficacy was noted dependent upon treatment initiation (57% on ID–1, 43% on ID0, and 29% on ID1) but was lower than demonstrated in other animal models. Analysis of the PK data indicated that BCV plasma exposure (maximum concentration [Cmax]) and the time of the last quantifiable concentration (AUClast) were lower than in other animal models administered the same doses, indicating that suboptimal BCV exposure may explain the lower protective effect on survival. IMPORTANCE Preparedness activities against highly transmissible viruses with high mortality rates have been highlighted during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Smallpox, caused by variola virus (VARV) infection, is highly transmissible, with an estimated 30% mortality. Through an intensive vaccination campaign, smallpox was declared eradicated in 1980, and routine smallpox vaccination of individuals ceased. Today's current population has little/no immunity against VARV. If smallpox were to reemerge, the worldwide results would be devastating. Recent FDA approval of one smallpox antiviral (tecovirimat) was a successful step in biothreat preparedness; however, orthopoxviruses can become resistant to treatment, suggesting the need for multiple therapeutics. Our paper details the efficacy of the investigational smallpox drug brincidofovir in a monkeypox virus (MPXV) animal model. Since brincidofovir has not been tested in vivo against smallpox, studies with the related virus MPXV are critical in understanding whether it would be protective in the event of a smallpox outbreak.


2019 ◽  
Vol 16 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Mohammad Aminianfar ◽  
Siavash Parvardeh ◽  
Mohsen Soleimani

Background: Clostridium botulinum causes botulism, a serious paralytic illness that results from the ingestion of a botulinum toxin. Because silver nanoparticle products exhibit strong antimicrobial activity, applications for silver nanoparticles in healthcare have expanded. Therefore, the objective of the current study was to assess a therapeutic strategy for the treatment of botulism toxicity using silver nanoparticles. Methods: A preliminary test was conducted using doses that produce illness in laboratory animals to determine the absolute lethal dose (LD100) of botulinum toxin type A (BoNT/A) in mice. Next, the test animals were divided into six groups containing six mice each. Groups I, II and III were the negative control (botulinum toxin only), positive control-1 (nano-silver only) and positive control-2 (no treatment), respectively. The remaining groups were allocated to the toxin that was supplemented with three nano-silver treatments. Results: The mortality rates of mice caused by BoNT/A significantly reduced in the treatment groups with different doses and injection intervals of nano-silver when compared to the negative control group. BoNT/A toxicity induced by intraperitoneal injection of the toxin of Clostridium botulinum causes rapid death while when coupled with nano-osilver results in delayed death in mice. Conclusion: These results, while open to future improvement, represent a preliminary step towards the satisfactory control of BoNT/A with the use of silver nanoparticles for human protection against this bioterrorism threat. Further study in this area can elucidate the underlying mechanism for detoxifying BoNT/A by silver nanoparticles.


Lupus ◽  
2018 ◽  
Vol 27 (8) ◽  
pp. 1296-1302 ◽  
Author(s):  
J Tanwani ◽  
K Tselios ◽  
D D Gladman ◽  
J Su ◽  
M B Urowitz

Background Lupus myocarditis (LM) is reported in 3–9% of patients with systemic lupus erythematosus (SLE) but limited evidence exists regarding optimal treatment and prognosis. This study aims to describe LM in a defined lupus cohort as compared with the existing literature. Patients and methods Patients with LM were identified from the University of Toronto Lupus Clinic database. Diagnosis was based on clinical manifestations and electrocardiographic, imaging, and biochemical criteria. Demographic, clinical, diagnostic and therapeutic variables and outcomes were collected in a standardized data retrieval form. A literature review was performed to identify cohort studies reporting on LM treatment and outcome. A comparative analysis was conducted between our patients and the combined cohort of the existing studies. Results Thirty patients were diagnosed with LM (prevalence 1.6%) and compared with a cumulative cohort of 117 patients from five distinct studies. No significant differences were found regarding the age at diagnosis (32.6 ± 13.4 years) and SLE duration (2.5 years median). Concomitant lupus activity from other organ systems was observed in 97% of the patients. Chest pain was more frequently reported in our cohort whereas dyspnea was more prominent in the other studies. Diagnostic criteria were similar across studies. Therapeutic approach was comparable and consisted of glucocorticosteroids (96.6%) and immunosuppressives (70%). Mortality was approximately 20% whereas another 20% of the patients achieved partial and 60% complete recovery. Conclusions LM usually occurs early in the disease course and in the context of generalized lupus activity. Despite aggressive therapy, approximately 40% of the patients died or had residual heart damage.


2020 ◽  
Vol 92 (2) ◽  
pp. 43-47
Author(s):  
Yu. G. Sandler ◽  
K. G. Saliev ◽  
S. N. Backih ◽  
S. G. Khomeriki ◽  
T. Yu. Khaymenova ◽  
...  

Due to the absence of the pathognomonic diagnostic criteria and to the diversity of clinical, serological and morphological manifestations, the diagnostic of the autoimmune hepatitis (AIH) remains to be a difficult task, which might lead to the delay of the timely beginning of the immunosuppressive therapy (IST), which in turn affects the disease outcomes. Aim.To studying the clinical, biochemical, immunological and morphological markers in patients with seronegative (SN) and seropositive (SP) AIH and the qualities of their response to the IST. Materials and methods.This retrospective cohort study included 82 AIH patients over the course of the years 20142019. All patients were selected in accordance with the criteria of the simplified assessment system of the IAIHG. Clinical, laboratorial and morphological characteristics of the AIH were analyzed. Therapy response was evaluated by the level of the ALT and IgG in 612 months after the start of the IST. The study material underwent statistical analysis using methods of parametrical and nonparametrical analysis. Statistical analysis was performed in the Statistica 13.3 (developed by StatSoft Inc., USA). Results.67/82 (81.70%) of the patients studied were women, median age of 54 years old [38; 70]. Patients with the diagnosis of the possible AIH according to the IAIHG made 85.4% (70 people). Almost everyone 96% (79/82) had morphological features of the interface-hepatitis with the lymphocytic/plasmocytic infiltration; emperipolesis was discovered in 63% of patients (49/82), hepatocellular rosette in 23% (19/82). Patients with SN AIH comprised 36.5% (30/82), with SP 63.4% (52/82). Comparative analysis demonstrated that the clinical profile in patients with SN and SP AIH is the same, while the incidence of immuno-associated diseases is significantly higher in the group of seronegative AIH. The morphological profile in the two AIH groups is identical in both typical and atypical manifestations. The number of responders to IST was 63% (19/30) SN AIH vs 67% SP AIH (35/52), did not differ significantly (p=0.529).However, that the number of patients with liver cirrhosis in the SN AIH group was twice as big as the ones with SP: 37% vs 17% (p=0.089). Conclusions.A comparative analysis of clinical, laboratory, morphological and clinical manifestations in the SN and SP AIH groups did not detected statistically significant significant differences, which may indicate that SN and SP AIH are the faces of one disease. It is possible that AB cannot be identified within the known spectrum of antibodies, or antibodies have slow expression, or are suppressed by the immune system. In any case, suspicions of AIH, in the absence of antibodies, it is recommended that liver biopsy be performed for the timely diagnosis of AIH and IST. Сirrhosis was more often diagnosed in the group SN AIH, which may be due to a later diagnosis, and therefore to untimely IST. The found frequent association of SN AIH with other immune-associated diseases requires a carefully study of this problem. The variety of clinical manifestations of AIH requires further study, the identification of clinical phenotypes with certain feature. This can help in the future to timely identify potentially problematic patients and predict a response to IST.


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