|Ferreira, Helena - Orise Fellow|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2018
Publication Date: 7/13/2018
Citation: Ferreira, H.L., Miller, P.J., Suarez, D.L. 2018. Protection against California 2002 NDV strain afforded by adenovirus vectored vaccine expressing Fusion or Hemagglutination-neuraminidase genes. Meeting Abstract. American Veterinary Medical Association Annual Meeting, July, 13-16, 2018, Denver, Colorado. CDROM.
Technical Abstract: Vectored vaccines expressing the combination of the hemagglutinin-neuraminidase (HN) and fusion (F) genes generally have better clinical protection against Newcastle disease virus (NDV) than when either the F and HN genes are expressed alone. Interestingly, the protection induced by F is usually better than HN alone, despite the great importance of HN for virus attachment, neuraminidase and fusion activities. The present study aimed to compare the clinical and virological protection induced by adenovirus vector expressing the F or HN alone and the combination of both proteins against a velogenic NDV challenge, California/2002, at 3 weeks post vaccination (wpv). Clinical signs and mortality were monitored during 14 days after challenge. Swabs were collected from all birds at days 2 and 4 post challenge (dpc) and blood was collected before the challenge and at 14 dpc from surviving birds. Birds vaccinated with adeno F and adeno F/HN with the highest dose had 100% of survival rate with no clinical signs. The survival rate ranged from 0 to 25% in other groups showing characteristic vNDV clinical signs. No specific antibody could be detected by HI at 3 wpv in any group whereas all surviving birds had high HI titers at 14dpc. Birds vaccinated with adenovirus F or/and F/HN had statistically significant lower RNA shedding compared to other groups at 2 and 4dpc in OP swabs and 4dpc in cloacal swabs. Comparisons with vaccine given as a booster will also be discussed.