foot-and-mouth disease vaccination strategies in …€¦ · biogénesis bagó s.a. (fmd national...
TRANSCRIPT
FOOT-AND-MOUTH DISEASE VACCINATION STRATEGIES IN SHEEP
AND LAMBS BY USING
COMMERCIAL OIL VACCINE
Späth, E., Robiolo, B.; León, E., Manazza, J., Duffy, S., Filippi,
J., Ham, A., La Torre, J., Smitsaart, E.
INTA-Balcarce, CEVAN-CONICET, CICVyA-INTA,
Biogénesis Bagó S.A. Argentina
Conclusions
• One dose of oil vaccine induces a duration of
immunity in adult sheep of at least one year
• A booster effect is observed shortly after
revaccination at 10, 20 or 30 days post primo
vaccination
• Lambs 30-90 days old with MDA respond to FMD
oil vaccine and produce high levels of antibodies
that persist at least for 4 months
Foot-and-mouth Disease Status South America. OIE, May 2008
Country No Free
• Ecuador
• Suriname
• Venezuela
Zone No Free
• Bolivia
• Brazil
• Colombia
• Peru
Area under intensive
surveillance
• Argentina
• Paraguay
• Brazil
• Bolivia
Country Free with vaccination
• Uruguay
Country Free without vaccination
• Chile
• French Guiana (French territory)
• Guyana
Zone Free without vaccination
• Argentina
• Brazil
• Colombia
• Peru
Zone Free with vaccination
• Argentina
• Brazil
• Colombia
• Bolivia
• Paraguay
Vaccination in sheep and lambs: background
• Emergency situation or buffer zone
• Appropriate strategies of vaccination in sheep needed
• Sheep good responder to FMD vaccination
• Results under field conditions by using conventional vaccine
needed
• Vaccination of lambs with MDA: few reports with significant
number of lambs
Materials & Methods
• Vaccine – Bioaftogen® water-in-oil single emulsion manufactured by
Biogénesis Bagó S.A. (FMD national campaigns 2004 &2005)
– Batch size: 2500 000 cattle doses (2 batches)
– BEI inactivated PEG concentrated and purified antigen: FMDV strains O1 Campos, A Arg 2000, A Arg 2001 & A24 Cruzeiro
– Sheep dose: 1 ml (Cattle dose: 2 ml)
• Trial 1: naïve sheep 1-4 years
1st dose 2nd dose N
– Group 1: T0 no 23– Group 2: T0 10 dpv 23– Group 3: T0 20 dpv 23– Group 4: T0 30 dpv 23– Non vacc: no no 10
Immuneresponse in adult sheep
0,00
0,50
1,00
1,50
2,00
2,50
3,00
3,50
4,00
4,50
0 50 100 150 200 250 300 350
days after primary vaccination
mean g
roup L
PB
E titr
es lo
g 1
0
(O1 C
am
pos)
P<0.05
0,5
1
1,5
2
2,5
3
0 50 100 150 200 250 300 350
days after primary vaccination
mean g
roup V
NT
titre
s t
o O
1 C
am
pos
(log 1
0)
Control
Group 1-1 dose
Group 2-rv 10
Group 3-rv 20
Group 4-rv 30
Liquid phase blocking
ELISA antibody titres
Neutralizing antibody titres
P<0.05
Reproductive time and vaccination/bleeding schedule in
adults and lambs
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR
BLEEDINGS ADULTS
BLEEDINGS LAMBS
LAMBING WEANING
2004 2005
VA
CC
INA
TIO
N
AD
UL
TS
VA
CC
INA
TIO
N
LA
MB
S
BREEDING
Trial 1 Trial 2
Experimental design: Trial 2
• Lambs born to
vaccinated ewes
Vaccination age N(days)
� G30: 30 28
� G60: 60 28
� G90: 90 30
� Non vaccinated 13
• Lambs born to non
vaccinated ewes� 4 lambs vaccinated at 30
days of age
� 2 lambs vaccinated at 90 days of ageNaïve sheep N=10
Immune response in lambs
0
0.5
1
1.5
2
2.5
3
3.5
4
0 20 40 60 80 100 120 140 160
days of age
Mate
rnally
derived a
ntibodie
s
in lam
bs b
y L
PB
E
(log 1
0)
A Arg 2001
O1 Campos
G-30 & w /o MDA vacc 30
00.5
11.5
22.5
33.5
4
30 60 90 120 150days of age
control non vacc-MDAG-30 w /o MDA vacc 30
G-60
00.5
11.5
22.5
33.5
4
30 60 90 120 150
days of age
LP
BE
antib
odie
s
log10 A
Arg
2001
control non vacc-MDA G-60
G-90 & w /o vacc 90
00.5
11.5
22.5
33.5
4
30 60 90 120 150
days of agecontrol non vacc-MDAG-90 w /o MDA vacc 90
Effect of maternally derived antibodies on primary response
• In lambs with high MDA titres (>log10 3.00),
there was a slightly impaired response at 30
dpv
• the biological impact of this suppression is
negligible as protective levels of antibodies
persisted during the whole trial.
Conclusions Recommendations
• One dose of oil vaccineinduces a duration ofimmunity in adult sheepof at least one year
• A booster effect isobserved shortly afterrevaccination at 10, 20 or 30 days post primo vaccination
• Lambs 30-90 days oldwith MDA respond toFMD oil vaccine andproduce high levels ofantibodies that persist at least for 4 months
• One or two dosesannually in adult sheep isrecommended forsystematic vaccinationprograms
• Two doses of oil vaccinein adult sheep, 10-30 days apart, isencouraged in order toenhance herd protectionin a high risk situation
• Vaccination of younglambs with high levels ofMDA is beneficial as thisinduces an effectiveimmune response
�
Thank you!