AN OVERVIEW OF REVERSE GENETIC APPROACHES TO ENHANCED FMD VACCINES
IN AFRICA
FMD in South Africa
Physical barriers, like fences
Immune barrier using vaccination
Endemic
cycle
Escape
Epidemic
cycle
Buffalo calves
African Buffalo herd
Other cloven-hooved animals
Livestock
Persistently
infected with
SAT viruses
Infection of
calves 6-18
months of age
The epidemiology of FMD in Africa is influenced
by two different patterns
Interaction between buffalo, FMDV and cattle
Principles'of'Virology,'ASM'Press
Reverse genetics for FMDV
Intra-serotype chimeric vaccine: clinical signs & viraemia
SAT2/ZIM/14/90
vSAT2
vSAT2ZIM14 -SAT2
A) Parental FMDV:
B) Chimeric FMDV constructs:
Vac
Vac
Chimera
Parental
Protected
ProtectedSevere tongue lesions 2 animals
High temperatures 2 animals
Systemic spread
Energetically favorable binding of Heparin moiety
Chitray 2018 PhD
SAT2-SAT2 chimera with added
positive charges at 5-fold axis
CHO-K1
Time (Hours)
0
1
2
3
4
5
6
0 1 2 4 6 10 13 17 20 22 24
Tite
r(lo
g1
0)
Growth kinetics in BHK-21 suspension cells
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 7 14 21 28
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0 7 14 21 28
SAT1 virus
SAT1/SAT2 chimera
B
C
Se
rum
tit
er
Se
rum
tit
er
Days post-vaccination
Days post-vaccination
0.6 ug
0.3 ug
1.2 ug
controls
0 2 4 7 11
16-1 0 3 1 0 0
16-2 0 1 0 0 0
16-3 0 0 0 0 0
16-4 0 1 0 0 0
16-5 0 1 1 0 0
11-1 0 10 9 2 2
11-2 0 13 9 5 2
6-1 0 5 2 0 0
6-2 0 3 1 0 0
6-3 0 0 0 0 0
6-4 0 0 0 0 0
6-5 0 0 0 0 0
13-1 0 0 0 0 0
13-2 0 5 3 0 0
13-3 0 0 0 0 0
13-4 0 0 0 0 0
13-5 0 0 0 0 0
14-1 0 0 0 0 0
14-2 0 0 0 0 0
14-3 0 0 0 0 0
14-4 0 0 0 0 0
14-5 0 0 0 0 0
11-3 0 10 9 2 2
11-4 0 13 9 5 2
8-1 0 0 0 0 0
8-2 0 0 0 0 0
8-3 0 0 0 0 0
8-4 0 0 0 0 0
8-5 0 0 0 0 0
5-1 0 0 1 1 0
5-2 0 0 0 0 0
5-3 0 0 1 1 0
5-4 0 0 0 0 0
5-5 0 0 0 0 0
1/4 Dose
1/16 Dose
Full
dose
Controls
1/4 Dose
1/16 Dose
Full
dose
Controls
SA
T1/S
AT
2 c
him
era
SA
T1
virus
Inter-serotype chimeric vaccine: Ab & clinical scores
Blignaut et al., 2011. J Virol.
Interactions at the capsid 2-fold interface and stability
Kotecha et al., 2015. Nature Struct Mol Biol.
Scott et al., 2017. J Virol.
Scott et al., 2017. Vaccine.
2-fold axis
WT
93Y
Top Related