Vaccine Efficacy Against a New Avian Influenza (H9N2) Field Isolate from the Middle East (Serology and Challenge Studies)

Gharaibeh, Saad; Amareen, Shadi

doi:10.1637/11123-050615-reg

Cited by 13 publications

(11 citation statements)

References 16 publications

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“…The negative control birds of the third treatment, that were vaccinated and deprived of both challenges, had a 100 % survival. The significant survival of vaccinated and challenged birds of first treatment is in agreement with other workers that documented a full protection against devastating diseases in poultry by autogenous killed vaccines, incorporating in it the homologous strain that is used in the challenge [25,26]. Researchers showed also the high efficacy of autogenous killed ND vaccine in protection against homologous v-NDV [27].…”

Section: Protection and Immunity By The Autogenous Nd Vaccinesupporting

confidence: 86%

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2017

IJVV

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This research had three complementary parts, in which the first investigated the broiler's protection on endemic areas with prevalence of v-NDV (genotype VI) by priming day-old broilers on farms with vectored-NDV vaccines and boosting with classical NDV Clone 30 versus priming and boosting on another farms with NDV Clone 30. The second part evaluated protection and immunity by a developed autogenous killed v-NDV in broilers against controlled challenge by genotype VI. The third part included seven broiler flocks on seven different farms located in v-NDV (genotype VI)-endemic area, introducing an additional subcutaneous dose of the developed autogenous vaccine at 6 days of age to their program of priming at d1 with vectored-NDV vaccine and boosting with NDV Clone 30 at d14. The additional autogenous vaccination was delivered to 100 tagged birds embedded in each flock of 22,000 birds. Results of the first part showed protection against genotype VI by NDV clone 30 alone and by combination of vectored-NDV vaccine and Clone 30 of 47.1 and 84.7%, respectively (P<0.05). Results of the second part showed that priming and boosting with the developed autogenous vaccine conferred a 100 % survival in Eimeria infected and non-infected birds that were challenged with v-NDV compared to 0.0% survivals in unvaccinatedchallenged controls (P<0.05). The acquired HI titers to hemaaglutinin and fusion proteins of genotype VI were significantly higher in the vaccinated birds compared to unvaccinated-challenged controls (P<0.05). The third part showed that the inclusion of an additional one dose of the autogenous NDV vaccine at 6 d of age improves protection in broilers by 6.5% compared to flocks deprived of this additional dose (P<0.05), and higher their HI titers at 21 d and 42 d of age.

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Section: Protection and Immunity By The Autogenous Nd Vaccinesupporting

confidence: 86%

Untitled

2017

IJVV

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“…In 2006–2007, serosurveillance and molecular detection in broilers ( n = 1561), layers ( n = 988), ducks ( n = 329) and pigeons ( n = 450) revealed widespread AIV H9N2 infection particularly in the Northern regions [80]. Vaccination of poultry in KSA is widely used and infections in vaccinated birds are not uncommon [81, 82].…”

Section: History and Epidemiology Of Aiv H9n2 In Poultry In The Me Anmentioning

confidence: 99%

“…The infection was very common in the broiler flocks and also concomitant was MG or Mycoplasma synoviae (MS) [89]. In 2013, a genetic drift H9N2 virus deviating from the vaccine strain was isolated from vaccinated broilers flocks with a history of increased mortality and severe clinical signs [81]. The HA gene of the isolated virus was only 89·1% identical to the vaccine strain HA gene.…”

Section: History and Epidemiology Of Aiv H9n2 In Poultry In The Me Anmentioning

confidence: 99%

A brief summary of the epidemiology and genetic relatedness of avian influenza H9N2 virus in birds and mammals in the Middle East and North Africa

2017

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H9N2 is the most widespread avian influenza virus subtype in poultry worldwide. It infects a broad spectrum of host species including birds and mammals. Infections in poultry and humans vary from silent to fatal. Importantly, all AIV, which are fatal in humans (e.g. H5N1, H7N9) acquired their 'internal' gene segments from H9N2 viruses. Although H9N2 is endemic in the Middle East (ME) and North Africa since the late 1990s, little is known about its epidemiology and genetics on a regional level. In this review, we summarised the epidemiological situation of H9N2 in poultry and mammals in Iran, Iraq, Kuwait, Qatar, United Arab Emirates, Oman, Bahrain, Yemen, Saudi Arabia, Jordan, Palestine, Israel, Syria, Lebanon, Turkey, Egypt, Sudan, Libya, Tunisia, Algeria and Morocco. The virus has been isolated from humans in Egypt and serosurveys indicated widespread infection particularly among poultry workers and pigs in some countries. Some isolates replicated well in experimentally inoculated dogs, mice, hamsters and ferrets. Insufficient protection of immunised poultry was frequently reported most likely due to concurrent viral or bacterial infections and antigenic drift of the field viruses from outdated vaccine strains. Genetic analysis indicated several distinct phylogroups including a panzootic genotype in the Asian and African parts of the ME, which may be useful for the development of vaccines. The extensive circulation of H9N2 for about 20 years in this region where the H5N1 virus is also endemic in some countries, poses a serious public health threat. Regional surveillance and control strategy are highly recommended.

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“…The SPF versus commercial bird (broiler, layer, or breeder) comparison for LPAIV infections (with or without complicating pathogens) has, however, never been properly investigated. The immune responses of two types of chickens have been compared to some extent in vaccine studies that aimed at understanding differences in vaccine protection in the laboratory and in the field (30,38,65,81). These studies show a better antibody response of SPF chickens than commercial birds, likely due to the differences among genetic lines of chickens in antibody development.…”

Section: Timing Of Coinfectionsmentioning

confidence: 99%