Publication Database

Immunization of turkeys with a DNA vaccine expressing the haemagglutinin gene of low pathogenic avian influenza virus subtype H9N2 (2020)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Shehata, Awad A.

Basiouni, Shereen

Ali, Ahmed

Fawzy, Mohamed

Hafez, Hafez M. (WE 15)

Ulbert, Sebastian

Vahlenkamp, Thomas

Quelle

Journal of Virological Methods

Bandzählung: 284

Seiten: Artikel 113938

ISSN: 0166-0934

Sprache

Englisch

Verweise

URL (Volltext): https://www.sciencedirect.com/science/article/abs/pii/S0166093420301907

DOI: 10.1016/j.jviromet.2020.113938

Pubmed: 32663531

Kontakt

Nutztierklinik: Abteilung Geflügel

Königsweg 63
14163 Berlin
+49 30 838 62676
gefluegelkrankheiten@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Low pathogenic avian influenza H9N2 is still circulating in the Middle East causing respiratory manifestations and severe economic losses in poultry. In the present study, an H9 plasmid-based DNA vaccine targeting the HA gene of H9N2 A/CK/Egypt/SCU8/2014 was developed and evaluated in turkeys. The full length of HA was cloned into vector plasmids under the control of a cytomegalovirus promoter. The in-vitro expression of the recombinant HA was demonstrated in HeLa cells transfected with the plasmids pVAX1-H9 or pCR-H9 using western blot and Immunofluorescent assay (IFA). The efficacy of pVAX-H9 and pCR- H9, naked or saponin-adjuvanted, was evaluated in turkey poults at 3 weeks and challenged with A/CK/Egypt/SCU8/2014 (106 EID50/bird at 3 weeks post-vaccination. The efficacy was assesses based on virus shedding, oropharyngeal and cloacal, as well as seroconversion using haemagglutination inhibition (HI) test. All immunized birds showed high HI antibody titers (7-8 log2) at 3 weeks post-vaccination. None of the birds vaccinated with naked or saponin-adjuvanted pVAX-H9 or pCR-H9 showed any clinical signs. The pVAX-H9 and pCR-H9 alone did not prevent cloacal and oropharyngeal virus shedding, however, saponin-adjuvanted pVAX1-H9 and pCR-H9 prevented cloacal and oropharyngeal virus shedding at 3 and 5 days post challenge, respectively. In conclusion, DNA vaccination with pVAX1-H9 and pCR-H9 could protect turkey from the H9N2 virus, but vaccination regimes need to be improved.