scholarly journals Protective efficacy of a prime-boost protocol using H5-DNA plasmid as prime and inactivated H5N2 vaccine as the booster against the Egyptian avian influenza challenge virus

2016 ◽  
Vol 60 (03) ◽  
pp. 307-315
Author(s):  
H. A. HUSSEIN ◽  
B. M. AHMED ◽  
S. M. ALY ◽  
A. H. EL-DEEB ◽  
A. A. EL-SANOUSI ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Protective Efficacy ◽  
Challenge Virus ◽  
Dna Plasmid

scholarly journals Development of Clade-Specific and Broadly Reactive Live Attenuated Influenza Virus Vaccines against Rapidly Evolving H5 Subtype Viruses

2017 ◽  
Vol 91 (15) ◽  
Author(s):  
Kobporn Boonnak ◽  
Yumiko Matsuoka ◽  
Weijia Wang ◽  
Amorsolo L. Suguitan ◽  
Zhongying Chen ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Protective Efficacy ◽  
Cross Reactivity ◽  
Influenza Viruses ◽  
Immune Memory ◽  
Challenge Virus ◽  
Wide Range ◽  
Ann Arbor ◽  
Clade 1 ◽  
Human Infections

ABSTRACT We have developed pandemic live attenuated influenza vaccines (pLAIVs) against clade 1 H5N1 viruses on an Ann Arbor cold-adapted (ca) backbone that induced long-term immune memory. In 2015, many human infections caused by a new clade (clade 2.2.1.1) of goose/Guangdong (gs/GD) lineage H5N1 viruses were reported in Egypt, which prompted updating of the H5N1 pLAIV. We explored two strategies to generate suitable pLAIVs. The first approach was to modify the hemagglutinin gene of a highly pathogenic wild-type (wt) clade 2.2.1.1 virus, A/Egypt/N03434/2009 (Egy/09) (H5N1), with its unmodified neuraminidase (NA) gene; this virus was designated Egy/09 ca. The second approach was to select a low-pathogenicity avian influenza H5 virus that elicited antibodies that cross-reacted with a broad range of H5 viruses, including the Egypt H5N1 viruses, and contained a novel NA subtype for humans. We selected the low-pathogenicity A/duck/Hokkaido/69/2000 (H5N3) (dk/Hok/00) virus for this purpose. Both candidate vaccines were attenuated and immunogenic in ferrets, inducing antibodies that neutralized homologous and heterologous H5 viruses with different degrees of cross-reactivity; Egy/09 ca vaccine antisera were more specific for the gs/GD lineage viruses but did not neutralize recent North American isolates (clade 2.3.4.4), whereas antisera from dk/Hok/69 ca-vaccinated ferrets cross-reacted with clade 2.3.4.4 and 2.2.1 viruses but not clade 1 or 2.1 viruses. When vaccinated ferrets were challenged with homologous and heterologous H5 viruses, challenge virus replication was reduced in the respiratory tract. Thus, the two H5 pLAIV candidates are suitable for clinical development to protect humans from infection with different clades of H5 viruses. IMPORTANCE In response to the continuing evolution of H5N1 avian influenza viruses and human infections, new candidate H5 live attenuated vaccines were developed by using two different approaches: one targeted a specific circulating strain in Egypt, and the other was based on a virus that elicits broadly cross-reactive antibodies against a wide range of H5 viruses. Both candidate vaccines were immunogenic and exhibited protective efficacy in ferrets. Our study permits a comparison of the two approaches, and the data support the further development of both vaccine viruses to optimally prepare for the further spread of clade 2.2.1 or 2.3.4.4 viruses.

scholarly journals Selectively targeting haemagglutinin antigen to chicken CD83 receptor induces faster and stronger immunity against avian influenza

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Angita Shrestha ◽  
Jean-Remy Sadeyen ◽  
Deimante Lukosaityte ◽  
Pengxiang Chang ◽  
Adrian Smith ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Ex Vivo ◽  
Protective Efficacy ◽  
Primary Vaccination ◽  
Single Chain ◽  
Challenge Virus ◽  
Virus Shedding ◽  
Single Chain Fragment Variable ◽  
Antigen Presenting ◽  
Influenza Virus Haemagglutinin

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.

scholarly journals Experimental Assessment of Possible Factors Associated with Tick-Borne Encephalitis Vaccine Failure

2021 ◽  
Vol 9 (6) ◽  
pp. 1172
Author(s):  
Ksenia Tuchynskaya ◽  
Viktor Volok ◽  
Victoria Illarionova ◽  
Egor Okhezin ◽  
Alexandra Polienko ◽  
...  
Keyword(s):  
Vaccine Efficacy ◽  
Protective Efficacy ◽  
Viral Rna ◽  
Dependent Manner ◽  
Related Factors ◽  
Effective Measure ◽  
Challenge Virus ◽  
Tick Borne Encephalitis ◽  
Tbe Virus ◽  
The Brain

Currently the only effective measure against tick-borne encephalitis (TBE) is vaccination. Despite the high efficacy of approved vaccines against TBE, rare cases of vaccine failures are well documented. Both host- and virus-related factors can account for such failures. In this work, we studied the influence of mouse strain and sex and the effects of cyclophosphamide-induced immunosuppression on the efficacy of an inactivated TBE vaccine. We also investigated how an increased proportion of non-infectious particles in the challenge TBE virus would affect the protectivity of the vaccine. The vaccine efficacy was assessed by mortality, morbidity, levels of viral RNA in the brain of surviving mice, and neutralizing antibody (NAb) titers against the vaccine strain and the challenge virus. Two-dose vaccination protected most animals against TBE symptoms and death, and protectivity depended on strain and sex of mice. Immunosuppression decreased the vaccine efficacy in a dose-dependent manner and changed the vaccine-induced NAb spectrum. The vaccination protected mice against TBE virus neuroinvasion and persistence. However, viral RNA was detected in the brain of some asymptomatic animals at 21 and 42 dpi. Challenge with TBE virus enriched with non-infectious particles led to lower NAb titers in vaccinated mice after the challenge but did not affect the protective efficacy.

Protective Efficacy of H7 Subtype Avian Influenza DNA Vaccine

2010 ◽  
Vol 54 (s1) ◽  
pp. 290-293 ◽  
Author(s):  
Yongping Jiang ◽  
Hongbo Zhang ◽  
Guojun Wang ◽  
Pingjing Zhang ◽  
Guobin Tian ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Dna Vaccine ◽  
Protective Efficacy ◽  
H7 Subtype

Protective Efficacy of H7 Subtype Avian Influenza DNA Vaccine

2010 ◽  
Vol 5 (s1) ◽  
pp. e39-e39
Author(s):  
Yongping Jiang ◽  
Hongbo Zhang ◽  
Guojun Wang ◽  
Pingjing Zhang ◽  
Guobin Tian ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Dna Vaccine ◽  
Protective Efficacy ◽  
H7 Subtype
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