Efficacy of inactivated AI H5 vaccines in SPF chicks against challenge with Egyptian H5N8 clade 2.3.4.4b viruses isolated in 2017 and 2018 /
Amena Abdelmoeid Sayed Mohamed
Efficacy of inactivated AI H5 vaccines in SPF chicks against challenge with Egyptian H5N8 clade 2.3.4.4b viruses isolated in 2017 and 2018 / المصرية المعزولة فى عامى2017 و 2018 b2.3.4.4 فرع H5N8 المثبطة فى الكتاكيت الخالية من المسببات المرضية ضد اختبار التحدى باستخدام فيروسى H5 فعالية لقاحات إنفلونزا الطيور Amena Abdelmoeid Sayed Mohamed ; Supervised Hussein Aly Hussein Ahmed , Ayman Hany Mahmoud Eldeeb , Mounir Mohamed Elsafty - Cairo : Amena Abdelmoeid Sayed Mohamed , 2021 - 116 P. : charts , facsimiles ; 25cm
Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Virology
Vaccination is the routinely used tool for control of highly pathogenic avian influenza (HPAI) H5N8subtype in Egypt. Inactivated avian influenza vaccines are the most frequently registered and commercially used against avian influenza (AI)infection in poultry farms. Both genetic and antigenic mismatching between the seed strain used invaccine and the recent circulating HPAI H5N8 viruses may affect the efficiency of commercial vaccines used in AIcontrol in Egypt.In this study, we evaluated inactivatedAI commercial vaccines (H5N1, H5N2 and H5N3) in challenge trials using specific pathogen free (SPF) chicks at 2 and 3 weeks post vaccination (WPV). Two Egyptian HPAI H5N8 viruses isolated in 2017 and 2018 clade 2.3.4.4bwere used. Survival percentages, antibody titers and the virus shedding titers as well as the histopathological changes in kidney and spleen were recorded.All studied vaccines revealed protection percentages between 70 to 100 % within 10 dayspost challenge. Haemagglutination inhibition (HI)results of sera samples showed antibody titers ranged from 0.6 to 5.4 log2 starting 1 week (PV) with the highest titers at 4thWPV. Vaccinated challenged SPF chicks showed remarkable virus shedding reduction with an average of 2 log10 compared to control birds. Various histopathological lesions with different scores were demonstrated. H5N1 and H5N3 AI vaccines were the most effective against the challenge HPAI H5N8 viruses. We recommend annual evaluation of the currently used vaccines using the most prevalent challenge H5N8 viruses isolated from field outbreaks in poultry farms based on the annual surveillance for AI in Egypt
Avian influenza Clade 2.3.4.4b Highly pathogenic H5N8
Efficacy of inactivated AI H5 vaccines in SPF chicks against challenge with Egyptian H5N8 clade 2.3.4.4b viruses isolated in 2017 and 2018 / المصرية المعزولة فى عامى2017 و 2018 b2.3.4.4 فرع H5N8 المثبطة فى الكتاكيت الخالية من المسببات المرضية ضد اختبار التحدى باستخدام فيروسى H5 فعالية لقاحات إنفلونزا الطيور Amena Abdelmoeid Sayed Mohamed ; Supervised Hussein Aly Hussein Ahmed , Ayman Hany Mahmoud Eldeeb , Mounir Mohamed Elsafty - Cairo : Amena Abdelmoeid Sayed Mohamed , 2021 - 116 P. : charts , facsimiles ; 25cm
Thesis (M.Sc.) - Cairo University - Faculty of Veterinary Medicine - Department of Virology
Vaccination is the routinely used tool for control of highly pathogenic avian influenza (HPAI) H5N8subtype in Egypt. Inactivated avian influenza vaccines are the most frequently registered and commercially used against avian influenza (AI)infection in poultry farms. Both genetic and antigenic mismatching between the seed strain used invaccine and the recent circulating HPAI H5N8 viruses may affect the efficiency of commercial vaccines used in AIcontrol in Egypt.In this study, we evaluated inactivatedAI commercial vaccines (H5N1, H5N2 and H5N3) in challenge trials using specific pathogen free (SPF) chicks at 2 and 3 weeks post vaccination (WPV). Two Egyptian HPAI H5N8 viruses isolated in 2017 and 2018 clade 2.3.4.4bwere used. Survival percentages, antibody titers and the virus shedding titers as well as the histopathological changes in kidney and spleen were recorded.All studied vaccines revealed protection percentages between 70 to 100 % within 10 dayspost challenge. Haemagglutination inhibition (HI)results of sera samples showed antibody titers ranged from 0.6 to 5.4 log2 starting 1 week (PV) with the highest titers at 4thWPV. Vaccinated challenged SPF chicks showed remarkable virus shedding reduction with an average of 2 log10 compared to control birds. Various histopathological lesions with different scores were demonstrated. H5N1 and H5N3 AI vaccines were the most effective against the challenge HPAI H5N8 viruses. We recommend annual evaluation of the currently used vaccines using the most prevalent challenge H5N8 viruses isolated from field outbreaks in poultry farms based on the annual surveillance for AI in Egypt
Avian influenza Clade 2.3.4.4b Highly pathogenic H5N8