scholarly journals Immunogenicity and Efficacy Evaluation of Subunit Astrovirus Vaccines

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 79 ◽  
Author(s):  
Mehdi R.M. Bidokhti ◽  
Karin Ullman ◽  
Anne Sofie Hammer ◽  
Trine Hammer Jensen ◽  
Mariann Chriél ◽  
...  

A full understanding of the immune response to astrovirus (AstV) infection is required to treat and control AstV-induced gastroenteritis. Relative contributions of each arm of the immune system in restricting AstV infection remain unknown. In this study, two novel subunit AstV vaccines derived from capsid protein (CP) of mink AstV (MAstV) such as CPΔN (spanning amino acids 161–775) and CPΔC (spanning amino acids 1–621) were evaluated. Their immunogenicity and cytokine production in mice, as well as protective efficacy in mink litters via maternal immunization, were studied. Truncated CPs induced higher levels of serum anti-CP antibodies than CP, with the highest level for CPΔN. No seronegativity was detected after booster immunization with either AstV CP truncates in both mice and mink. All mink moms stayed seropositive during the entire 104-day study. Furthermore, lymphoproliferation responses and Th1/Th2 cytokine induction of mice splenocytes ex vivo re-stimulated by truncated CPs were significantly higher than those by CP, with the highest level for CPΔN. Immunization of mink moms with truncated CPs could suppress virus shedding and clinical signs in their litters during a 51-day study after challenge with a heterogeneous MAstV strain. Collectively, AstV truncated CPs exhibit better parameters for protection than full-length CP.

Author(s):  
Ferdi Oguz ◽  
Harika Atmaca

Vaccination is one of the important approaches in the prevention and control of diseases. Although the capacity to present antigens other than the disease-specific antigen in the traditional vaccine composition provides a potential benefit by increasing its protective efficacy, many components that are not needed for the related disease are also transferred. These components can reduce vaccine activity by lowering immunity against protective antigens. The reasons such as the low effectiveness of traditional vaccines and the high cost of production and time-consuming reasons show that it is necessary to develop a new vaccine method for our world, which is struggling with epidemics almost every year. Among nucleic acids, mRNA has many advantages, such as genomic integration, induction of anti-DNA autoantibodies, and immune tolerance induced by long-term antigen expression. mRNA vaccines have become a therapeutic target for reasons such as efficacy, safety, fast and non-expensive production. The fact that mRNA triggers both humoral and cellular immunity and goes only to the cytoplasm, not to the nucleus, makes it highly efficient. The mRNA must cross the lipid bilayer barrier and entry to the cytoplasm where it is translated into protein. There are two main ways of mRNA vaccine delivery for this: ex vivo loading of mRNA into dendritic cells and direct injection of mRNA with or without a carrier. Studies continue to understand which delivery system is therapeutically more efficient. Preclinical and clinical trials showed that mRNA vaccines trigger a long-lasting and safe immune response.


Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Yuwan Li ◽  
Yangyi Zhang ◽  
Yingxin Liao ◽  
Yawei Sun ◽  
Yang Ruan ◽  
...  

Senecavirus A (SVA), formerly known as Seneca Valley virus (SVV), causes vesicular symptoms in adult pigs and acute death of neonatal piglets. This pathogen has emerged in major swine producing countries around the world and caused significant economic losses to the pig industry. Thus, it is necessary to develop strategies to prevent and control SVA infection. Herein, an SVA strain (named GD-ZYY02-2018) was isolated from a pig herd with vesicular symptoms in Guangdong province of China in 2018. The present study aimed to carry out the phylogenetic analysis of the GD-ZYY02-2018 strain, determine its pathogenicity in finishing pigs, and assess the protective efficacy of the inactivated GD-ZYY02-2018 strain against virus challenge. The results of phylogenetic analysis showed that the SVA GD-ZYY02-2018 strain belonged to the USA-like strains and had a close genetic relationship with recent Chinese SVA strains. Animal challenge experiment showed that 100-day-old pigs inoculated intranasally with SVA GD-ZYY02-2018 strain developed vesicular lesion, low fever, viremia, and virus shedding in feces. The immunization challenge experiment showed that pigs vaccinated with inactivated GD-ZYY02-2018 strain could produce a high titer of anti-SVA neutralizing antibody and no vesicular lesion, fever, viremia, and virus shedding in feces was observed in vaccinated pigs after challenge with GD-ZYY02-2018 strain, indicating that inactivated GD-ZYY02-2018 could protect finishing pigs against the challenge of homologous virus. In conclusion, preliminary results indicated that inactivated GD-ZYY02-2018 could be used as a candidate vaccine for in-depth research and might be conducive to the prevention and control of SVA infection.


npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Angita Shrestha ◽  
Jean-Remy Sadeyen ◽  
Deimante Lukosaityte ◽  
Pengxiang Chang ◽  
Adrian Smith ◽  
...  

AbstractThe immunogenicity and protective efficacy of vaccines can be enhanced by the selective delivery of antigens to the antigen-presenting cells (APCs). In this study, H9N2 avian influenza virus haemagglutinin (HA) antigen, was targeted by fusing it to single-chain fragment variable (scFv) antibodies specific to CD83 receptor expressed on chicken APCs. We observed an increased level of IFNγ, IL6, IL1β, IL4, and CxCLi2 mRNA upon stimulation of chicken splenocytes ex vivo by CD83 scFv targeted H9HA. In addition, CD83 scFv targeted H9HA induced higher serum haemagglutinin inhibition activity and virus neutralising antibodies compared to untargeted H9HA, with induction of antibodies as early as day 6 post primary vaccination. Furthermore, chickens vaccinated with CD83 scFv targeted H9HA showed reduced H9N2 challenge virus shedding compared to untargeted H9HA. These results suggest that targeting antigens to CD83 receptors could improve the efficacy of poultry vaccines.


2020 ◽  
Vol 7 (2) ◽  
pp. 199-204
Author(s):  
Shrikant Verma ◽  
Mohammad Abbas ◽  
Sushma Verma ◽  
Syed Tasleem Raza ◽  
Farzana Mahdi

A novel spillover coronavirus (nCoV), with its epicenter in Wuhan, China's People's Republic, has emerged as an international public health emergency. This began as an outbreak in December 2019, and till November eighth, 2020, there have been 8.5 million affirmed instances of novel Covid disease2019 (COVID-19) in India, with 1,26,611 deaths, resulting in an overall case fatality rate of 1.48 percent. Coronavirus clinical signs are fundamentally the same as those of other respiratory infections. In different parts of the world, the quantity of research center affirmed cases and related passings are rising consistently. The COVID- 19 is an arising pandemic-responsible viral infection. Coronavirus has influenced huge parts of the total populace, which has prompted a global general wellbeing crisis, setting all health associations on high attentive. This review sums up the overall landmass, virology, pathogenesis, the study of disease transmission, clinical introduction, determination, treatment, and control of COVID-19 with the reference to India.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 784
Author(s):  
Sylvia Reemers ◽  
Sander van Bommel ◽  
Qi Cao ◽  
David Sutton ◽  
Saskia van de Zande

Equine influenza virus (EIV) is a major cause of respiratory disease in horses. Vaccination is an effective tool for infection control. Although various EIV vaccines are widely available, major outbreaks occurred in Europe in 2018 involving a new EIV H3N8 FC1 strain. In France, it was reported that both unvaccinated and vaccinated horses were affected despite >80% vaccination coverage and most horses being vaccinated with a vaccine expressing FC1 antigen. This study assessed whether vaccine type, next to antigenic difference between vaccine and field strain, plays a role. Horses were vaccinated with an ISCOMatrix-adjuvanted, whole inactivated virus vaccine (Equilis Prequenza) and experimentally infected with the new FC1 outbreak strain. Serology (HI), clinical signs, and virus shedding were evaluated in vaccinated compared to unvaccinated horses. Results showed a significant reduction in clinical signs and a lack of virus shedding in vaccinated horses compared to unvaccinated controls. From these results, it can be concluded that Equilis Prequenza provides a high level of protection to challenge with the new FC1 outbreak strain. This suggests that, apart from antigenic differences between vaccine and field strain, other aspects of the vaccine may also play an important role in determining field efficacy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ashwani Kesarwani ◽  
Parul Sahu ◽  
Kshama Jain ◽  
Prakriti Sinha ◽  
K. Varsha Mohan ◽  
...  

AbstractDue to the limited utility of Bacillus Calmette–Guérin (BCG), the only approved vaccine available for tuberculosis, there is a need to develop a more effective and safe vaccine. We evaluated the safety and efficacy of a dry powder aerosol (DPA) formulation of BCG encapsulated alginate particle (BEAP) and the conventional intradermal BCG immunization in infant rhesus macaques (Macaca mulatta). The infant macaques were immunized intratracheally with DPA of BEAP into the lungs. Animals were monitored for their growth, behaviour, any adverse and allergic response. The protective efficacy of BEAP was estimated by the ex-vivo H37Rv infection method. Post-immunization with BEAP, granulocytes count, weight gain, chest radiography, levels of liver secreted enzymes, cytokines associated with inflammation like TNF and IL-6 established that BEAP is non-toxic and it does not elicit an allergic response. The T cells isolated from BEAP immunized animals’ blood, upon stimulation with M.tb antigen, secreted high levels of IFN-γ, TNF, IL-6 and IL-2. The activated T cells from BEAP group, when co-cultured with M.tb infected macrophages, eliminated largest number of infected macrophages compared to the BCG and control group. This study suggests the safety and efficacy of BEAP in Non-human primate model.


Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2063
Author(s):  
Awad A. Shehata ◽  
Shereen Basiouni ◽  
Reinhard Sting ◽  
Valerij Akimkin ◽  
Marc Hoferer ◽  
...  

Poult enteritis and mortality syndrome (PEMS) is one of the most significant problem affecting turkeys and continues to cause severe economic losses worldwide. Although the specific causes of PEMS remains unknown, this syndrome might involve an interaction between several causative agents such as enteropathogenic viruses (coronaviruses, rotavirus, astroviruses and adenoviruses) and bacteria and protozoa. Non-infectious causes such as feed and management are also interconnected factors. However, it is difficult to determine the specific cause of enteric disorders under field conditions. Additionally, similarities of clinical signs and lesions hamper the accurate diagnosis. The purpose of the present review is to discuss in detail the main viral possible causative agents of PEMS and challenges in diagnosis and control.


Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 784
Author(s):  
Angita Shrestha ◽  
Jean-Remy Sadeyen ◽  
Deimante Lukosaityte ◽  
Pengxiang Chang ◽  
Marielle Van Hulten ◽  
...  

Improving the immunogenicity and protective efficacy of vaccines is critical to reducing disease impacts. One strategy used to enhance the immunogenicity of vaccines is the selective delivery of protective antigens to the antigen presenting cells (APCs). In this study, we have developed a targeted antigen delivery vaccine (TADV) system by recombinantly fusing the ectodomain of hemagglutinin (HA) antigen of H9N2 influenza A virus to single chain fragment variable (scFv) antibodies specific for the receptors expressed on chicken APCs; Dec205 and CD11c. Vaccination of chickens with TADV containing recombinant H9HA Foldon-Dec205 scFv or H9HA Foldon-CD11c scFv proteins elicited faster (as early as day 6 post primary vaccination) and higher anti-H9HA IgM and IgY, haemagglutination inhibition, and virus neutralisation antibodies compared to the untargeted H9HA protein. Comparatively, CD11c scFv conjugated H9HA protein showed higher immunogenic potency compared to Dec205 scFv conjugated H9HA protein. The higher immune potentiating ability of CD11c scFv was also reflected in ex-vivo chicken splenocyte stimulation assay, whereby H9HA Foldon-CD11c scFv induced higher levels of cytokines (IFNγ, IL6, IL1β, and IL4) compared to H9HA Foldon-Dec205 scFv. Overall, the results conclude that TADV could be a better alternative to the currently available inactivated virus vaccines.


Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 86
Author(s):  
Weiwei Zeng ◽  
Yingying Wang ◽  
Huzi Hu ◽  
Qing Wang ◽  
Sven M. Bergmann ◽  
...  

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.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1240
Author(s):  
Wan-Ching Cheng ◽  
Lois Wilkie ◽  
Tsumugi Anne Kurosawa ◽  
Melanie Dobromylskyj ◽  
Simon Lawrence Priestnall ◽  
...  

Aortic thromboembolism (ATE) occurs in cats with cardiomyopathy and often results in euthanasia due to poor prognosis. However, the underlying predisposing mechanisms leading to left atrial (LA) thrombus formation are not fully characterised. von Willebrand Factor (vWF) is a marker of endothelium and shows increased expression following endothelial injury. In people with poor LA function and LA remodelling, vWF has been implicated in the development of LA thrombosis. In this study we have shown (1) the expression of endocardial vWF protein detected using immunohistofluorescence was elevated in cats with cardiomyopathy, LA enlargement (LAE) and clinical signs compared to cats with subclinical cardiomyopathy and control cats; (2) vWF was present at the periphery of microthrombi and macrothrombi within the LA where they come into contact with the LA endocardium and (3) vWF was integral to the structure of the macrothrombi retrieved from the atria. These results provide evidence for damage of the endocardial endothelium in the remodelled LA and support a role for endocardial vWF as a pro-thrombotic substrate potentially contributing to the development of ATE in cats with underlying cardiomyopathy and LAE. Results from this naturally occurring feline model may inform research into human thrombogenesis.


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