6 z.penzes mechanism and strategies ibd protection (final)...strategies of ibd vaccination types of...

Strategies and mechanism ofStrategies and mechanism ofStrategies and mechanism of Strategies and mechanism of protection against Gumboro diseaseprotection against Gumboro disease

ZZoltánoltán PPéénzenzes DVM PhDs DVM PhDZZoltánoltán PPéénzenzes, DVM, PhDs, DVM, PhDDirector, R&D Virology Director, R&D Virology

Ceva-Phylaxia Veterinary Biologicals Co. Ltd. Budapest, Hungary

Gumboro Symposium, Budapest Hungary, Jan 19, 2012. ZPenzes

1

AgendaSt t i d h iStrategies and mechanism

Live attenuated 0Live attenuated

Inacti atedInactivatedmainly for booster vaccinationprovide high level long-lasting immunity

40

provide high level, long-lasting immunity

Vectored (recombinant) vaccinesrecombinant turkey herpesvirus (HVT) expressing therecombinant turkey herpesvirus (HVT) expressing the protective antigen (VP2) of IBDV

Immune complex vaccineImmune complex vaccineIntermedier plus (live attenuated) + antibody

Gumboro Symposium; Budapest, Hungary. Jan 19, 2012. Z Penzes

2

Strategies of IBD vaccinationg

Types of vaccines:

Immune-complex concept with VPIConcept of

vectored vaccinesvectored vaccines Cevac Transmune

in ovo”rHVT-IBD

Live attenuatedvaccines

„in ovo or day-old

in the hatcherymild

intermedierintermedier plus

„in ovo” or day-old

in the hatcheryp

DW in the

Gumboro Symposium; Budapest, Hungary. Jan 19, 2012. Z Penzes* Virus Protecting Immunoglobulin

field

3


Types of vaccines:



in ovo”rHVT-IBD



in the hatcherymild



in the hatcheryp

DW in the


field

4

Types of vaccinesLive attenuatedvaccines

Conventional live IBD Vaccines

ypvaccines

Mild IBD VaccineEasily eliminated by low levels of maternal antibody.

Intermediate VaccineRelatively safe to use in ovo or at hatch. Eli i t d b l t d t l l f t l i itEliminated by low to moderate levels of maternal immunity.

Intermediate Plus VaccineN t f t i i t h t h ith t t l tib d lNot safe to give in ovo or at hatch without maternal antibody unless modified in some manner. Eliminated by higher level maternal immunity.


5

Main issues of protection and successful vaccination


Determination of the correct time of vaccination(s)

and successful vaccinationvaccines

Determination of the correct time of vaccination(s)Differences in the level of maternal antibodies

8

5

6

7

8

bir

ds

Mean = 2977 C.V.=29%

3

4

5

6

7

mb

er o

f b

ird

s

Mean = 3923 C.V.= 67 %

Homogeneous titres Poorly homogeneous titresC.V. = 67%

0

1

2

3

4

5

Nu

mb

er o

f

0

1

2

3

0-14

9

0-39

9

0-99

9

-199

9

-299

9

-399

9

-499

9

-599

9

-799

9

-999

9

1199

9

1499

9

1799

9

2199

9

2599

9

2999

9

3499

9

4099

9

Nu

m

gC.V. = 29%

0

0-14

9

150-

399

400-

999

1000

-199

9

2000

-299

9

3000

-399

9

4000

-499

9

5000

-599

9

6000

-799

9

8000

-999

9

1000

0-11

999

1200

0-14

999

1500

0-17

999

1800

0-21

999

2200

0-25

999

2600

0-29

999

3000

0-34

999

3500

0-40

999

ou p

lus.

..

ELISA titres classes

15 40

1000

2000

3000

4000

5000

6000

8000

1000

0-1

1200

0-1

1500

0-1

1800

0-2

2200

0-2

2600

0-2

3000

0-3

3500

0-4



*CV; coefficient variation


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Timing of vaccinationLive attenuatedvaccines

AGE AT VACCINATION VARIES ACCORDING TO EPIDEMIOLOGICALEPIDEMIOLOGICAL SITUATIONSITUATION and VACCINE TYPEVACCINE TYPE

Timing of vaccination vaccines

Antibody titre

Passive immunity

EPIDEMIOLOGICAL EPIDEMIOLOGICAL SITUATIONSITUATION and VACCINE TYPEVACCINE TYPE

Vaccine takelevel

Vaccine take

Protection levelvvIBDV

Intermediate plus vaccine

levelIntermediate

vaccine

Protection levelclassical IBDV

D1 Age


Age at vaccination

7

Main issues of protection and successful vaccination


Field application of IBD vaccine by drinking water


Field application of IBD vaccine by drinking waterFactors of successful drinking water vaccination

• ~2h water deprivation• Chlorine neutralizer• Uniform filling of drinkersg• Force birds to move• Vaccination in ~2 hours• Check coverage with blue dye• Check coverage with blue dye• ...


8

Mechanism and protectionLive attenuatedvaccines

Vaccination – challenge trial (V Palya et al )

pvaccines

Vaccination – challenge trial (V. Palya et al.)Objective

Study onset and level of protection against vvIBDV usingStudy onset and level of protection against vvIBDV using different vaccine strainsdifferent vaccine strains

Experimental setup3-week-old SPF chickens vaccinatedvaccinated with • intermedier plus (W2512) or • intermedier (D78) strain• intermedier (D78) strain

ChallengeChallenge with vvIBDV on day 2, 3, 4, and 5 post vaccination

Protection evaluated Protection evaluated by bursa histology at 4 days post challenge


9

Mechanism and protectionLive attenuatedvaccines


pvaccines

Vaccination – challenge trial (V. Palya et al.)Protection evaluated by bursa histology

Intermedier plusvaccine (W2512)• full bursa protectionfull bursa protection

already at 2 day postvaccination (p.v.)

D24D25

D28D29

D21Hatch D23 D27D24 D28


Vaccination ChallengevvIBDV

Bursa histopathology

*RFLP; restriction fragment length polymorphism10

Mechanism and protectionLive attenuatedvaccines pvaccines


D26 D30

Vaccination – challenge trial (V. Palya et al.)Protection evaluated by bursa histology

D21Hatch D24 D28D25 D29

D23

Vaccination ChallengevvIBDV

Bursa histopathology

Intermedier vaccine (D78)vaccine (D78)• partial bursa

protection at 5 dayspost vaccination


post vaccination

*RFLP; restriction fragment length polymorphism11

Main issues of protection d f l i ti


Mechanism of protection



C ti ltiter

Conventional vaccine

NO vaccine take!

„vaccine take” range

14 18 24 31 .......days of age

28

vaccination

Hatch


12

Main issues of protection d f l i ti





C ti ltiter

Conventional vaccine

Vaccine take!

„vaccine take” rangei ti

14 18 24 31 .......days of age

28

vaccination

Live attenuated intermediate plus vaccines (W2512) inhibit the replication of the challenge virus in the bursa soon after colonizationsoon after colonization

Hatch


replication of the challenge virus in the bursa soon after colonization soon after colonization of the bursa by the vaccine virus of the bursa by the vaccine virus (vaccine-take) (within 2 days of vaccination) 13


Types of vaccines:



in ovo”rHVT-IBD



in the hatcherymild



in the hatcheryp

DW in the


field

14

How is a vectored rHVT IBD constructed?

Concept of vectored vaccines rHVT-IBD constructed?

VECTORANTIGEN (IBDV VP2)

vectored vaccines

PurifiedHVT genomeHomology plasmid

Transfection

gy p

Cell culture Homologous recombination

Transfection

recombination

RecombinantVirus


15

Vectored rHVT-IBD vs.normal” HVT

Concept of vectored vaccines „normal” HVTvectored vaccines

diff ti ti

Vectored rHVT-IBD „Normal” HVTdifferentiation by PCR only


Presence of IBDV VP2 in the cells (chicken)16

How does it work?Concept of vectored vaccines

Vaccination (in ovo or s.c.)

vectored vaccines

( )Replication of rHVT-IBD

primarily in the spleen, white blood cells,feather follicule epithelium

Slowly increasing production of IBDV VP2 protective antigenprotective antigenof IBDV VP2 protective antigenprotective antigen

Stimulation of the immune system yproduction of increasing level of circulating IBDV VP2 antibodies

Once sufficiently high amounts of antibodies are accumulatedantibodies are accumulated... IBDV


protection develops, neutralization of an IBD challenge virus would be possible 17

How does it work?Characteristics of protection

Concept of vectored vaccines Characteristics of protection


vectored vaccines

Mechanism of protectionbased on circulating VP2 antibodies

there is no „colonization” no „colonization” of the bursa by rHVT-IBD

HVT IBD li ti d t d ti f b irHVT-IBD replication does not cause reduction of bursa size

in rHVT-IBD vaccinated birds, bursa atrophy can be thein rHVT IBD vaccinated birds, bursa atrophy can be the result of partial protection against IBDV challenge

protection develops gradually and partiallygradually and partially


18

Evaluation of bursal protection in broilersbroilersfollowing vvIBDV challenge

Concept of vectored vaccines following vvIBDV challenge

Vaccination – Challenge trial in broilers

vectored vaccines

gHatch Group 1 Group 2 Group 3 Control

1-day-old (D0) rHVT-IBD „A”

rHVT-IBD „B”

rHVT-IBD „C”

non-vaccinated

„very virulent” IBDV challenge (n=15/group)

0.1 ml s.c.

„ y g ( g p)

post challenge day 4 .„Standard” parameters

post challenge day 10 .

bl d li (ELISA VN)

of evaluation

vaccination

vvIBDV challenge bursa histology

b d d/ b i ht

blood sampling (ELISA, VN)


body and/or bursa weight

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Evaluation of bursal protection in broilersfollowing vvIBDV challenge

Concept of vectored vaccines following vvIBDV challenge

rHVT-IBD vaccinated broiler chicken

vectored vaccines

vvIBDV challenge was done around the onset of protection...

At 10 days post vvIBDV challenge• some bursa already protected, healthy• some bursa not yet protected, chronic lesion atrophyy p p y• some bursa may show acute histological lesions!

• this suggests „delayed onset of challenge virus replication” (or „partial, developing protection” after rHVT-IBD vaccination)


20

Histological analysis of partially protected bursae at 10 dpch

Concept of vectored vaccines protected bursae at 10 dpch

„typical” picture of a non-protected b 10 d ft IBDV h ll

vectored vaccines

bursa 10 days after vvIBDV challenge„uniform” damage,all follicules are affected,follicular structure destroyed

„on-off” protection of follicules after rHVT-IBD vaccination and vvIBDV ch.

fully protected and damaged follicules side by sideindependent from the rHVT-IBD pstrain used



Types of vaccines:



in ovo”rHVT-IBD



in the hatcherymild



in the hatcheryp

DW in the


field

22

The in ovo vaccinationImmune-complex concept with VPIconcept with VPI

Background

Ability of the chick and the embryo to develop an immune response

g

immune response.

1985 Sharma: first in ovo Gumboro vaccination1985, Sharma: first in ovo Gumboro vaccination.But, MDA or safety problems:

Mild and Intermediate vaccines: safe for embryos but susceptible to MDAIntermediate plus vaccines: efficacious in front of MDA but unsafe for embryos without MDA


23

The immune-complex conceptImmune-complex concept with VPI p p

Background

concept with VPI

The „predecessor” of the technology1897:

g

1906:• Marion Dorset developed a virus-serum inoculation of pigs

against classical swine feverM. Dorset

against classical swine fever

Until 1940:• Hutyra and Köves, Phylaxia veterinarians used the

simultaneous injection of virulent virus and serum against


classical swine fever

24

The immune-complex conceptImmune-complex concept with VPI p pconcept with VPI

Discovery of the technology in the 1990s:the 1990s:

• immune-complex vaccine developed by Craig WhitfillCraig Whitfill, Univ. Arkansas, against Gumboro diseaseGu bo o d sease

Gumboro live virus + serum (1997)

Newcastlesubunits + serum (1993)live virus + serum (2003)

Reovirusconcept, live virus + serum (2003)

...


25

IBD Immune complex vaccineIBD - Immune-complex vaccine.How does it work?

26

How does it work?Immune-complex concept with VPIconcept with VPI


27


1-day-old In ovo(0 05 l)(0.1 ml SQ) (0.05 ml)


28


1-day-old In ovo(0 05 l)(0.1 ml SQ) (0.05 ml)


29


F ollicularD entritic C ells

in the spleen


30

Working mechanism of CEVAC Transmune

Immune-complex concept with VPI CEVAC Transmune

Neutralization

concept with VPI

+Neutralization

of virusMDAMDAIBDV

Dissociation of the complex

VPI

High MDA

p

bloodstream

FDC

Receptor Fc

Low

IBDVIBDV

Low MDA

Immune response

FDC: spleen, follicular dendritic cellsIBDV: infectious bursal disease virusVPI: virus protecting immunoglobulinsMDA: maternal antibodies

Replication in the bursa


MDA: maternal antibodies

31

Working mechanism of CEVAC Transmune

Immune-complex concept with VPI CEVAC Transmuneconcept with VPI

Immune response

FDCresponse

bursa

FDC MDAFDC(Follicular dendritic cells)

MDA(Maternal antibodies)


32

Visualisation of Cevac Transmune vaccine virus in the bursa

Immune-complex concept with VPI vaccine virus in the bursaconcept with VPI

14-day-old SPF birds. Cevac Transmune administered at 1 day of age


(in situ hybridization, using labelled DNA probe).33

Immune-complex concept with VPI The concept of constant protectionconcept with VPI p p

titerVaccine take

and protection

Cevac Transmune

in all cases!

„vaccine take” range

vaccination

-3 14 18 24 31 .......days of age

28


34

SummarySummarySt t d h iStrategy and mechanism


vectored vaccinesLive attenuated in ovo or s.c. in the

drinking water application i th fi ld

vaccines in ovo or s.c. in the hatchery

hatcheryno need for date determinationin the field

correct vaccination time determination is key

NO bursa colonization NO bursa colonization by the vaccine virus

bursa colonization bursa colonization by the vaccine virusWinterfield 2512strain-dependent protection

bursa colonizationbursa colonization by the

protection is solely antibody based

Winterfield 2512 safety and efficacycompatible with Marek vaccinesbursa colonization bursa colonization by the

vaccine virusfor intermediate plus strains full bursa protection withinfull bursa protection within

gradual buildgradual build--up of up of protectionprotection

vaccinesfull protection once full protection once the bursa is colonizedthe bursa is colonized


35

full bursa protection within full bursa protection within 2 days post vaccination2 days post vaccination

Thank you for your attention!Thank you for your attention!Thank you for your attention!Thank you for your attention!

19121912 201220121912 1912 -- 20122012

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6 z.penzes mechanism and strategies ibd protection (final)...strategies of ibd vaccination types of...

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