The Vaccine

The Vaccine

The vaccine targets and objectives

Onchocerciasis (river blindness) vaccine candidates

Antigen
(expression
system)
Location In vitro
L3
killing
In vivo
L3 killing
In vivo
Adult killing
In vivo
Microfilaria
killing
CPI-2M
(bacteria )
ES,
Surface,
all stages
Ov L3
94%
Ov >30%
(rProtein )
Ls 50%
(rProtein )
Bm >45%
(rProtein)
Ls 70%
(DNA)
Ls >85%
(DNA)
Ls >85%
(synthetic
peptide)
RAL-2
(bacteria)
ES, surface,
all stages
Ov L3
100%
Ov >40%
(rProtein )
Bm >60%
(rProtein )
Bm >90%
(rProtein )
103
(yeast)
Surface,
all stages
Ov L3
100%
Ov Mf
>90%
Ov >35%
(rProtein )
Bm >40%
(rProtein)
Ls >90%
(DNA)

Onchocerciasis (river blindness) vaccine candidatesPercentages represent killing in vitro (human antigen-specific antibodies + neutrophils) or reduction in parasite burden in vivo
ES, excreted-secreted antigens
rProtein, recombinant protein
Ov, Onchocerca volvulus
Bm, Brugia malayi
Ls, Litomosoides sigmodontis

L3, third stage infective larvae
Mf, microfilaria

Protecting children, reducing morbidity and transmission

Our goal is production and testing of a river blindness vaccine through Phase I trials by 2020.

It is envisaged that the onchocerciasis vaccine will be used initially to protect vulnerable children (<5 years of age) living in loiasis co-endemic areas. The vaccine will reduce adult worm burden and fecundity with consequential reduction in pathology associated with microfilariae. In addition, a vaccine will find use in ongoing ivermectin MDA areas and contribute to reduction in transmission rates; and, will protect areas where local elimination may have been achieved.