Inactivated and live bivalent fowl adenovirus (FAdV8b + FAdV11) breeder vaccines provide broad-spectrum protection in chicks against inclusion body hepatitis (IBH) Ashish Gupta a , Shelly Popowich a , Davor Ojkic b , Shanika Kurukulasuriya a , Betty Chow-Lockerbie a , Thushari Gunawardana a , Kalhari Goonewardene a , Ruwani Karunarathna a , Lisanework E. Ayalew a , Khawaja Ashfaque Ahmed a , Suresh K. Tikoo d , Philip Willson c , Susantha Gomis a,⇑ a Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada b Animal Health Laboratory, University of Guelph, P.O. Box 3612, Guelph, ON N1H 6R8, Canada c Canadian Centre for Health and Safety in Agriculture, University of Saskatchewan, Saskatoon SK S7N 5E5, Canada d Vaccinology and Immunotherapeutic Program, School of Public Health, University of Saskatchewan, Saskatoon, SK S7N 5E3, Canada article info Article history: Received 27 September 2017 Received in revised form 6 December 2017 Accepted 9 December 2017 Available online xxxx Keywords: Bivalent fowl adenovirus vaccine FAdV Broiler breeder vaccination Broad-spectrum protection Inclusion body hepatitis abstract Fowl adenovirus (FAdV) is comprised of five species (A to E) and 12 serotypes (1–7, 8a, 8b, 9–11). Inclusion body hepatitis (IBH) is caused by FAdV-7, 8a, 8b (species E) and FAdV-2 and 11 (species D). Commercial vaccines against IBH are not available in Canada. Autogenous FAdV broiler breeder vaccines are now used in some areas where outbreaks of IBH are occurring. The objective of this study was to eval- uate the efficacy of a bivalent (species D and E) live and an inactivated FAdV broiler breeder vaccine in protecting broiler chicks against IBH through maternal antibody (MtAb) transfer. FAdV seronegative broi- ler breeders (n = 300/group) received either a live or inactivated bivalent (FAdV-8b-SK + FAdV-11-1047) vaccine. The live vaccine (1  10 4 TCID 50 of each virus/bird) was given orally once at 16 weeks of age and the inactivated vaccine (1  10 6 TCID 50 of each virus + 20% Emulsigen D) was given intramuscularly at 16 and 19 weeks of age. Controls (n = 150) were given saline orally. The inactivated vaccine group was boosted 3 weeks later with the same vaccine. Neutralizing antibodies (NAb) in sera (n = 10) were detected at 19, 22, 30 and 48 weeks of age. NAb were able to neutralize various FAdV serotypes within species D and E. Mean NAb were similar in the both live and killed vaccine groups at 19, 30 and 48 weeks and ranged from 2.4 to 3.7 log 10 . Approximately 26 ± 7% of MtAbs were passively transferred through eggs to day-old chicks. Progeny challenged with a lethal dose (1  10 7 TCID 50 /bird intramuscularly) of FAdV-8b-SK, FAdV-11-1047, or FAdV-2-685 (n = 90/group) at 14 days post-hatch (dph) showed 98– 100% protection in broiler chicks to homologous or heterologous FAdV challenges. Our data suggests that a bivalent live and an inactivated FAdV vaccine are equally effective and have the potential for the control of IBH. Ó 2017 Published by Elsevier Ltd. 1. Introduction Inclusion body hepatitis (IBH) is an economically important fowl adenovirus (FAdV) disease of 2–5 weekold broiler chickens [1–3]. The disease has also been reported within a week of hatch in broilers [4] as well as in pullets [5]. IBH is characterized by increased flock mortality that varies between 2% and 30% [5–7]. Although five species (A to E) and 12 serotypes (1–7, 8a, 8b, 9– 11) of FAdVs are known [1,8], IBH is primarily caused by FAdV-7, 8a and 8b of species E and FAdV-2 and 11 of species D [5,9–12]. FAdV-8a, 8b and 11 are the predominant serotypes associated with outbreaks of IBH in Canada [11,13]. The existence of multiple FAdV https://doi.org/10.1016/j.vaccine.2017.12.047 0264-410X/Ó 2017 Published by Elsevier Ltd. Abbreviations: dph, days post-hatch; dpv, days post-vaccination; EID 50 , embryo infectious dose 50; FAdV, fowl adenovirus; HHS, hepatitis-hydropericardium syndrome; IBH, inclusion body hepatitis; LMH, leghorn male hepatoma; MtAb, maternal antibodies; NAb, neutralizing antibodies; qPCR, quantitative real time polymerase chain reaction; TCID 50 , tissue culture infective dose 50; VNT, virus neutralization test. ⇑ Corresponding author at: Department of Veterinary Pathology, Western College of Veterinary Medicine, 52 Campus Dr., University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada. E-mail address: susantha.gomis@usask.ca (S. Gomis). Vaccine xxx (2017) xxx–xxx Contents lists available at ScienceDirect Vaccine journal homepage: www.elsevier.com/locate/vaccine Please cite this article in press as: Gupta A et al. Inactivated and live bivalent fowl adenovirus (FAdV8b + FAdV11) breeder vaccines provide broad-spec- trum protection in chicks against inclusion body hepatitis (IBH). Vaccine (2017), https://doi.org/10.1016/j.vaccine.2017.12.047