Detailed description of different Vaccine candidates and Immunisation trials against Haemonchus contortus

1. Vaccination against Haemonchus contortus
Dr. ISHFAQ MAQBOOL
MVSc SCHOLAR
DIVISION OF PARASITOLOGY

2. Introduction
 Haemonchus contortus
 Ubiquitous and highly pathogenic.
 Mostly in tropical and sub-tropical countries
(Kalita et al., 1978)
 Temperate regions with focal areas of similar climatic conditions
(Waller et al., 2004; Waller et al., 2006)
 In India
- 3 species of Haemonchus
- H. contortus, H. longistipes and H. similis
(Sood, 1981)

3. Life cycle

4.  A female lays around 5000-10000 eggs/day
 0.05 – 0.07 ml/parasite/day leading to anaemia.
(Malviya et al.,1979; Soulsby, 1982)
 Punctiform haemorrhages in abomasal mucosa
 Hypoproteinemia, bottle jaw
 ↓ Digestion and absorption of proteins, calcium and phosphorus (Sood, 1981)
 Decreased feed conversion, malnutrition, loss of appetite, low fertility indices and in certain
cases death of young animals
(Quiroz et al., 1984)

5.  Economic losses are incurred through morbidity, mortality and increased investment
due to cost of preventative as well as curative treatments
(Miller et al., 2006)
 GI parasites in sheep alone cause annual losses ranging from US $ 42 million to US $
222 million
(Waller, 2006)
 Losses due to GI parasites in sheep was estimated to be US $500 million in Australia
and $946 million in New Zealand
(Emery, 1991;Vlassoff and McKenna, 1994)
 Estimated treatment cost alone for H. contortus per year in India was US $103 million
(McLeod, 2004)
 Chronic haemonchosis is very common and of considerable economic importance
(Newton and Munn, 1999)
Economic Importance

6.  Anthelminthic resistance
(Kaplan et al., 2005; Burke and Miller, 2006)
 Demand for “clean and green” animal products free of residual chemicals and growth
promoters
(Waller, 2003)
 Increasing toxicity and persistence of chemical residues in the environment
(Wolstenholme et al., 2004)
 Immunization with irradiated L3 stage larvae
(Mulligan et al., 1961)
- Failure to protect young lambs
(Smith and Christie, 1979)
Need for Immunoprophylaxis

7. How it works?
Adequate control can be achieved with vaccine efficacies of about 80%
(Barnes et al. 1995)

8. Natural or Surface or E/S antigens
(Emery et al., 1999; Alunda et al., 2003)
Hidden or Concealed antigens
(Smith, 1999; Knox et al., 1999)
Types of Antigens

9.  Schallig et al 1997 identified adult 15 and 24 kDa as immunogenic polypeptides in
ES products of H.contortus
 Gomez-Munoz et al., 1995 identified and purified 26 kDa somatic antigen but
Cornelissen, 1996 concluded that 26-kDa Somatic and the 24-kDa E/S antigens of
Haemonchus contortus one and the same differing in glycosylation
 Karanu et al.,1993 identified Cysteine proteinases in excretory-secretory (ES)
products with estimated molecular weights (Mr) of 32, 35, 38, and 40 kDa
Natural antigens

10.  Gut antigens of fourth larval stage (L4) and adult parasites
 Contortin: (Munn, 1977 )
Helical polymeric structure attached to the luminal surface of the intestinal cells
 Aminopeptidase H11 glycoprotein: (Munn et al.,1992 )
It runs on (SDS-PAGE) as a doublet with a mean value of 110 kDa
It has microsomal (membrane) aminopeptidase M and microsomal aminopeptidase A
activities attributable to distinct isoforms
(Smith et al 1997, Graham et
al 1993)
 Haemonchus galactose-containing glycoprotein complex: (Smith et al., 1994 )
It contains aspartyl, metallo- and cysteine proteinases. Major component is a family of four
zinc metallo-endopeptidases, designated MEPs 1–4, MEP3 being most dominant
(Smith et al., 1999)
Hidden antigens…

11.  p52 and p46: Mixture of two gut surface proteins of 52 and 46 kDa obtained by affinity
chromatography
(Sharp et al., 1992)
 Cysteine proteinases and Glutamate dehydrogenase :
The expression of the GDH and cysteine protease encoding genes coincides with the onset
of blood-feeding
 Cysteine proteinase:
Cathepsin-B family expressed in intestine of adult worms
(Rehman and Jasmer, 1999;Skuce et al., 1999)
Cysteine proteases in H. contortus are capable of digesting Hb, fibrinogen, collagen and
IgG (Knox et al., 1993)
 GDH:
Predominant portion of S3 TSBP of 60 kDa (Knox et al. 1995)
Expressed in the cytoplasm of the intestinal cells (Skuce et al., 1999)
Hidden antigens…

12.  Fractionate and vaccinate approach
(Emery and Wagland, 1991)
 Gut antigens
 H11 (Munn et al., 1993)
 H-gal-GP (Smith et al., 1994, 1999)
 Cysteine protease (Knox et al., 1995)
 Use of immune serum
 15 and 24 kDa ES Ag (Schallig et al., 1994)
 Use of ASC probes
 HcsL3 (Meeusen et al., 1995)
Identification of Immunodominant antigens

13. Antigen Animal
specifications
Protection Immunoglobulin Reference
r15/24 Lambs
Adults
55% FECR
49% FECR
Low IgA,IgG,IgE level Vervelde et al.,2002
rHcp26/23 All age groups No significant protection Strong IgG and
Lymphoproliferative
response
Leticia et al .,2010
rH11 6 m old lambs No significant protection - Sexton and Zawadski .,2005
H-gal-GP Blackface × Leicest
er male lambs, aged
9 months
No significant protection High levels of
immunoglobulins
Smith et al.,2003
Cachet et al.,2010
Cysteine
Proteinase
Hc58
Sheep
Goat (7-8 m)
29-38%
Slight protection
Strong correlation
Increase in IgA,IgG and
Mucosal IgA level
Redmond and Knox.,2004
Muleke et al.,2007
rHc23 Lambs (6-7 m) >80% FEC
85% WB reduction
Increased level of
IgA,IgG,IgE
Fawzi et al.,2015
Vaccination with recombinant Ag’s

14. Recombinant
Antigen
Reason/s for Failure Reference
15 and 24 kDa Redundancy Newton and Meeusen.,2003
p26/23 Lack of glycosylation Leticia et al .,2010
H-gal-GP Inappropriate glycosylation and/or
conformational folding
Smith et al., 2003a
Smith et al., 2003b
H-gal-GP Failure to identify the protective component
of the complex, or the requirement for the
antigen(s) to be presented in a complex form
Newton and Meeusen.,2003
H11 Inappropriate glycosylation and/or
conformational folding
Haslam et al., 1996
Munn et al.,1997
Newton and Meeusen.,2003
H11 Lack of additional components that are
present in native H11-enriched extract
Roberts et al., 2013
Cysteine
proteinase
Inappropriate folding Redmond and Knox.,2004
Failure of vaccination with rAg

15. Antigen/dose Adjuvant Animal
specifications
Efficacy Immunoglobulin Reference
15 and 24 kDa
50-100µg
DDA Lambs 72.9%FEC reduction
82.2% WB reduction
Strong correlation Schallig & van
Leeuwen, 1997;
Schallig et al., 1997
15 and 24 kDa
50-100µg
DDA Sheep 82% WB reduction in
9 m old
77% in 6m old
0% in 3m old
Strong correlation Kooyman et al.,2000
p26/23 DDA Lambs >60% FEC
>61.6% WB
reduction
Strong correlation Domınguez-Torano et
al., 2000
Cysteine protease Aluminum
hydroxide
Lambs 77%FEC reduction
and 47% WB
reduction
Significantly higher
local and systemic
ES specific IgA and
IgG responses.
Boisvenue et al., 1992
Bakker et al., 2004
De Vries et al. (2009)
Hc-sL3
20 µg
Aluminum
hydroxide
Five month old
lambs
61% FEC reduction
69% WB reduction
No difference Jacobs et al., 1999
Hc23
100 µg
Al(OH)3
Bacterial
Lambs 70.67%,85.64% FEC
67.1% , 86% WB
reduction
respectively
Strong correlation Fawzi et al., 2014
Vaccination with native natural Ag

16. Antigen Animal
specifications
Efficacy Immunoglobulin
levels
Reference
Contortin Lambs 75% reduction in worm burden Strongly correlated Munn et al., 1987
p52 and p46 Lambs 78% FEC reduction
33%WB reduction
- Smith et al., 2000
p52 and p46 14-month-
old goats
34% FEC reduction and 53%
WB reduction
- Jasmer et al., 1993
Cysteine proteinase
S3 TSBP
S3 TSBP
S3 TSBP
Purified cysteine protease
S3 TSBP
Purified cysteine protease
Sheep
Goats
Lambs
Lambs
Lambs
95% FECR,50% WBR
77% FECRand 47%WBR
89% FECRand 68%WBR
Comparable results
Significant protection
Significant protection
Predominant IgG2 response
High IgG levels
High levels of antibody
Knox et al., 1995
Knox et al.,1999
Ruiz et al., 2004
Knox et al., 2005
Redmond et al., 2006
Molina et al., 2015
Vaccination with native hidden Ag

17. Antigen/dose/adju
vant
Animal
specifications
Efficacy Immunoglobulin
levels
Reference
H11 50 µg
FCA/FIA
Young Dorset lambs 78% FECR
83% WB reduction
Significant
correlation
Tavernor et al. 1992
H11 fraction
0.35µg FCA/FIA
Young merino lambs 70.7% FECR
70% WB reduction
Significant
correlation
Munn et al., 1993
H11 140µg
H11 200µg
4 month old lambs 94.6% FEC reduction
86.5% and 93.5% male and
female WB reduction
respectively
Significant
correlation
Smith et al., 1994
H11 from
resistant
strains150µg
FCA/FIA
Lambs 99% FECR
90% WB reduction
Significant
correlation
Newton et al., 1994
H11 (4
isolates)150µg
FCA/FIA
Lambs 82–96% FECR 55.9–93.8%WB
reduction
Significant
correlation
Newton et al., 1994
H11 50 µg
FCA/FIA .
Pregnant ewes 91% FECR
86% WB reduction
Significantly higher,
Colostral transfer
Andrews et al., 1995
H11 40 µg Vax
saponin
Lambs 99.9% FECR
93.6% WB reduction
Significant
correlation
Roberts et al.., 2013
Vaccination with native H11

18. Antigen/dose/adjuv
ant
Animal
specifications
Efficacy Immunoglobulin
levels
Reference
H-gal-GP 200 µg in
FCA
Suffolk x Dorset 3-5
m old lams
89% FECR
69.5% WB
reduction
Significant
correlation
Smith & Smith .,1996
H-gal-GP 100µg
FCA/FIA
5-6 m old lambs 56.5–69.7 % FECR
40–53.5%% WB
reduction
Significant
correlation
Smith et al. ,1999
H-gal-GP 100µg
Quil A
Lambs 83.4% WB
reduction
Significant
correlation
Newlands et al.., 1999
H-gal-GP 100 µg
Quil A
Lambs 93% FECR
60–64%WB
reduction
Significant
correlation
Smith et al. ,2000
Smith et al. ,2003
Smith et al. ,2007
H-gal-GP 100 µg
Quil A
Lambs 88.5% FECR
72.3% WB
reduction
Significant
correlation
Cachat et al. ,2010
Vaccination with native H-gal-GP

19. Location Animal
specification
Antigen ,dose and
adjuvant
Efficacy Reference
Lousiana,USA Suffolk ewes>2y 100 µg H11+100 µg H-
gal-GP in 5 µg Quil A
>65%FECR Kabagambe et al., 2000
South Africa 12-18 m old Dorper
sheep
100 µg H11+100 µg
H-gal-GP in 5 µg Quil
A
>82% FECR Smith et al., 2001
Australia Grazing merino
lambs
100 µg H11+100 µg H-
gal-GP in 5 µg Quil A
>85% FECR
High levels of
IgG1 and
IgG2
LeJambre et al., 2008
Brazil Periparturient
ewes
5 or 50 µg H11 and 1mg
of saponin as adjuvant
78% FECR Bassetto et al., 2014
Field trials in sheep

20.  1st
commercially available sub-unit vaccine against H. contortus developed by Dr.
David Smith of Moredun Research Institute, Edinburgh , UK.
 Manufactured by Dept. of Agriculture and Food, Albany, Western Australia
 5µg native gut integral protein + 1mg saponin adjuvant /dose (1ml Subcutaneously)
 5 doses for lambs during the summer Haemonchus risk period
 Reduces the periparturient rise – epidemiological benefit to flock

21. Thank you