1. Academy of Military Medical Science
Vaccination of dogs using a recombinant canine adenovirus type-2 viral vector confers long-lasting immunity against rabies
Veterinary Institute
Academy of Military Medical Science
Changchun, Jilin, China
28 May, 2007
Paris

2. Human rabies in China in the most recent decade
159
222
229
343
495
891
1191
2037
2651
2548
3215
500
1000
1500
2000
2500
3000
3500
1996
1997
1998
1999
2002
2003
2004
2005
2006
2001
Year
Human rabies in China in the most recent decade
Human rabies cases geological distribution in China

3. Rabies reservoir or vectors in China
Dogs: 98%
Cats: 4-5%
Badger: 15 cases were reported
Rats: in some areas in the south of China
Foxes: Inner Mongolia
Wolves: Xinjiang
Bats:?

4. Vaccines for dogs in China
ERA: in five combined vaccines
Flury LEP: approved for two years
Inactivated (imported) : Intervet, Merial,
Fort Dodge
Inactivated (home-made): 3-4 types, in
clinical trial, not yet approved
* Vaccination of inactivated vaccine in rural areas needs laborious work.

5. Oral vaccines for dogs Attenuated or mutated live rabies virus SAD-B19
SAG1
SAG2
reverse genetically modified ……
Recombinant live virus vector
Poxvirus-vector based
Adenovirus-vector based

6. Advantages of adenovirus
Safe
Wide range of host
Heat stable (Oral infection)
Median package of a foreign gene
Persistent existence ?

7. Adenovirus Hu RL et al. Microbes Infect, 2006, 8(4): 1090-1097
Liu Y, Hu R, Zhang S, et al Viral Immunology, 2006(19), 2:
Patent1:
Patent2:
Non-essential for replication
Foreign gene or label inserts
Fiber
pIX

8. Strategies for recombinant virus construction
Homologous recombination
Gene cloning

9. Our constructs Glycoprotein: SRV9 CVS-24 8202(street strain)
Nucleoprotein:
The recombinant CAV-2 genome containing the rabies virus glycoprotein expression cassette in plasmid form

10. Production of the recombinant virus
MDCK cells
CPE
Western blot
analysis
Handling of canine adenovirus (safe)
MDCK easy grown
Obvious CPE
High titer: around 10(8.5)

11. Bait composition Five parts: the recombinant virus solution;
pledget; tallow; metal frame;
paper package

12. Bait uptake

13. Vaccination and antibody induction in dogs
Inoculation routes
Total No. dogs
Take the baits
or vaccinated
Develop neutralizing antibody
Antibody last for 2 years at a protective level
Bait
(oral) 96
90/96
79/90 (87.8%)
72/90(80.0%)
Solution (intranasal) 46
46/46
40/46 (87.0%)
36/46(78.3%)

14. Antibody production and persistence

15. Challenge results of dogs orally vaccinated and the negative controls
Groups
Number of dogs died after different time of vaccination
Dogs survived
1 week
2 weeks
3 weeks
4 weeks
5 weeks
Orally vaccinated 10
Negative control 6 3 1

16. Prospect
In cats
In pigs
In cattle
and more
Dogs
Bats

17. Conclusions A new, safe and efficacious rabies vaccine
A simple and useful bait
For oral use
Long lasting immunization in dogs