Post on 25-Dec-2015
Evaluation of avian influenza vaccines on commercial layer
chicks
M.M. Amer, Sherein, S.abdelgayed and Abeer, A. Abd El-Baky
Introduction
• Avian influenza Avian influenza (AI) (AI) is one of the highly is one of the highly contagious Office of International contagious Office of International Epizootics Epizootics (OIE) (OIE) list list “A”“A” diseases. The diseases. The disease is also called disease is also called “fowl plague” “fowl plague” due due to its high mortality in chicken. to its high mortality in chicken.
• On rare occasions, AI viruses have On rare occasions, AI viruses have exhibited interspecies transmissibility exhibited interspecies transmissibility to human. to human.
Introduction
• Different levels of control measures have Different levels of control measures have
been implemented to control the been implemented to control the
outbreaks that included condemnation of outbreaks that included condemnation of
infected farms, strict bio-security and infected farms, strict bio-security and
vaccination of commercial chickens vaccination of commercial chickens
• Vaccination as a supportive tool in AI Vaccination as a supportive tool in AI
virus control strategies was implemented virus control strategies was implemented
to limit spread of H5N1 and to reduce the to limit spread of H5N1 and to reduce the
losses. losses.
Introduction
• Different types of vaccines are Different types of vaccines are
already in use that decrease already in use that decrease
shedding of virus, morbidity, shedding of virus, morbidity,
mortality and transmissibilitymortality and transmissibility
• through increasing resistance to through increasing resistance to
infection and reducing field virus infection and reducing field virus
replication.replication.
Introduction
• Evaluation of different types of AI Evaluation of different types of AI
vaccines used in Egypt may provide vaccines used in Egypt may provide
effective vaccination strategy.effective vaccination strategy.
• Moreover, Moreover, the combinant vaccine of the combinant vaccine of
avian influenza and Newcastle avian influenza and Newcastle
disease (AI&ND) was recently disease (AI&ND) was recently
recommended and commercialized recommended and commercialized
for more protection against AI.for more protection against AI.
Purpose of the study
The purpose of the current study was to
•Evaluate inactivated monovalent (H5N1) and Evaluate inactivated monovalent (H5N1) and
bivalent (H5N1&ND) AI vaccines bivalent (H5N1&ND) AI vaccines
•through its immune response, through its immune response,
clinicopathological and histopathological clinicopathological and histopathological
effects on vaccinated layer chicks.effects on vaccinated layer chicks.
Materials and MethodsMaterials and MethodsExperimental designExperimental design
Materials and MethodsMaterials and Methods Sampling Sampling
Materials and MethodsMaterials and Methods Sampling Sampling
Results and Discussion
Results and Discussion
Results and Discussion
Results and Discussion3- Clinicopathological Findings Erythrogram Erythrogram mean values (packed cell
volume (PCV %), hemoglobin concentration (Hb),
erythrocytes count (RBCs), mean corpuscular
volume (MCV) and mean corpuscular hemoglobin
concentration (MCHC)) of different experimental
groups, in comparison to those of control
group (A) showed, insignificant changes in
vaccinated groups B and C.
Results and Discussion3- Clinicopathological Findings Leukogram Mean values of leukogram [total leukocyte
count (TLC), neutrophil, lymphocyte and
monocyte counts] of different experimental
groups showed significant leukocytosis due
to significant lymphocytosis started from the
2nd week in all experimental groups.
Results and Discussion3- Clinicopathological Findings LeukogramThis lymphocytosis was a result of
immunostimulatory effect of vaccination.
Lymphocytosis which observed in group C
(vaccinated with bivalent AI vaccine) was higher than those in group B (vaccinated with monovalent AI vaccine)
The avian influenza vaccines have been shown to induce antigen specific lymphocyte responses that may explain the observed lymphocytosis
Results and Discussion3- Clinicopathological Findings Serum Biochemical Evaluation Compared to control group, protein profile
results showed no significant changes were
observed in albumin concentration.
while, significant hyperproteinemia due to
hyperglobulinemia with significant decrease in
A/G ratio started from 2nd week in all experimental
groups was recorded.
Results and Discussion3- Clinicopathological Findings Serum Biochemical Evaluation This hyperglobulinemia may be attributed to
the high levels of gamma globulins
(immunoglobulin especially IgG and IgA)
associated with chicken vaccination by AI vaccine
Hyperglobulinemia which observed in group C
(vaccinated with bivalent AI vaccine)
was higher than those in group B
(vaccinated with monovalent AI vaccine).
Results and Discussion3- Clinicopathological Findings Serum Biochemical EvaluationActivities of serum liver enzymes (AST, ALT and ALP)
and concentrations of blood glucose, serum creatinine and uric acid showed; insignificant changes throughout the experiment in all groups.
This revealed that the vaccination with both
inactivated monovalent and bivalent AI vaccines
did not affect liver and kidney functions.
Results and Discussion
4- Histopathological Findings
Bursa of Fabricious
1st week
All groups were normal
Bursa of fabricious from all groups at 1week showing apparently normal lymphoid Follicles (H&E X 200).
Results and Discussion
4- Histopathological Findings Bursa of Fabricious
2nd & 3rd weeksGroups A & C were normal.
Group B revealed interfollicular
congestion
Bursa of fabricious from group B at 2nd & 3rd weeks showing interfollicular congestion (H&E X 200).
Results and Discussion4- Histopathological Findings
Bursa of Fabricious
4th & 5th weeksGroup A was normal.
Group B revealed interfollicular edema at 4th week and normal follicles at 5th week.
Group C revealed lymphocytic hyperplasia and lymphoblastic activation at4th&5thweeks
Bursa of fabricious from group B at 4th week showing interfollicular edema (H&E X 200).
Bursa of fabricious from group C at 4th & 5th week showing lymphocytic hyperplasia and lymphoblastic activation
(H&E X 200).
Results and Discussion
4- Histopathological Findings Thymus
1st & 2nd weeks
All groups were normal
Thymus from all groups at 1st & 2nd weeks showing apparently normal cortex and medulla (H&E X 200).
Results and Discussion
4- Histopathological Findings Thymus
3rd week
Groups A & C were normal
Group B showed congested medulla
Thymus from group B at 3rd week showing congested medulla (H&E X 200).
Results and Discussion
4- Histopathological Findings Thymus
4th & 5th weeks
Groups A & B were normal
Group C showed slight lymphocytic
hyperplasia
Thymus from group C at 4th & 5th weeks showing revealed slight lymphocytic hyperplasia
(H&E X 200).
Results and Discussion
4- Histopathological Findings Spleen
1st & 2nd weeks
All groups were normal
Spleen from all groups at 1st & 2nd weeks showing apparently normal lymphoid follicles (H&E X 200).
Results and Discussion
4- Histopathological Findings Spleen
3rd & 4th weeksgroups A & C were normal
Group B showed slight lymphocytic
depletion
Spleen from group B at 3rd & 4th weeks showing slight lymphocytic depletion
(H&E X 200).
Results and Discussion
4- Histopathological Findings Spleen
5th week
Group A & B were normal
Group C showed lymphoblastic activation
Spleen from group C at 5th week showing lymphoblastic activation (H&E X 200).
From the present study, it is concluded that,
Bivalent (H5N1&ND)AI vaccine has immunostimulatory effect higher than monovalent (H5N1)AI vaccine.
which reflected on increasing the immune response of its vaccinated chicken against AI virus.
which manifested by its higher globulins concentration and higher mean (HI) antibody titers of chicken against avian influenza virus (AIV) and confirmed histopathologically by the observed hyperplasia of the lymphoid organs.
Conclusion