Avian Influenza Vaccines in China

1
Avian Influenza Vaccines in China

• Kangzhen Yu
• China Institute of
• Veterinary Drug Control

2
(No Transcript)
3
Avian influenza in China timeline

• 1970s-1980s LP AIVs isolated from ducks
• 1992 LP H9N2 AIVs isolated from chickens with
  clinical signs
• 1996 First HP H5N1 AIV isolated from geese
• 2004 First HP H5N1 AI outbreak in domestic
  birds in Jan
• 2005 First HP H5N1 AI outbreak in migratory
  birds in April

4
1996 First HP H5N1 AIV isolated from
geese
A/goose/Guangdong/1/96
IVPI 2.1
5
2004 First HP H5N1 AI outbreak in
domestic birds in Jan
6
In 2004, 50 outbreaks in 16 provinces, 144.9
thousand domestic birds infected, 129.1k died,
9.05 million slaughtered.
7
In 2005, 31 outbreaks in 12 provinces, 163.1k
infected, 154.6k died, 22.57m depopulated. In
addition, an outbreak in migratory birds occurred
in Qinghai.
8
In 2006, 10 outbreaks in 7 provinces, 90k
infected, 47k died, 2.94m culled.
9
So far in 2007, only 3 outbreaks in the whole
country.
10
2005 First HP H5N1 AI outbreak in
migratory birds in April in Qinghai
11
HA gene of the H5N1 viruses isolated in 2005-2006
Wild birds clade (2005-2006, BHG/QH/06)
Waterfowl clade (2005-2006, DK/HuB/05)
Xinjiang Clade (2005, CK/XJ/05 )
Shanxi Clade (2006, CK/SX/06)
12
Antigenic analysis of the H5N1 viruses isolated
in 2005-2006 in China
13
Avian influenza vaccines in China

• Inactivated whole virus vaccines
• H9N2 naturally isolated low pathogenic H9N2
  virus
• H5N2 laboratory adapted naturally isolated low
  pathogenic H5N2 virus
• Inactivated reverse genetics vaccines
• H9N2 artificial generated high growth H9N2/PR8
  reassortant virus
• H5N1 artificial generated high growth H5N1/PR8
  reassortant virus
• Live virus vectored vaccines
• H5N1 double recombinant fowlpox virus
• H5 recombinant Newcastle disease virus

14
Avian influenza vaccines in China

• Inactivated whole virus vaccines
• H9N2 naturally isolated low pathogenic H9N2
  virus
• H5N2 laboratory adapted naturally isolated low
  pathogenic H5N2 virus
• Inactivated reverse genetics vaccines
• H9N2 artificial generated high growth H9N2/PR8
  reassortant virus
• H5N1 artificial generated high growth H5N1/PR8
  reassortant virus
• Live virus vectored vaccines
• H5N1 double recombinant fowlpox virus
• H5 recombinant Newcastle disease virus

15
Inactivated whole virus vaccines

• H9N2, inactivated
• H9N2
• H9N2ND
• H9N2H5N2
• H9N2NDIB
• H5N2, inactivated

16
H5N2 vaccines is immunogenicfor chickens
HI titer (log2)
HI antibody titers (log2)
Weeks after immunization
Weeks after vaccination
17
Avian influenza vaccines in China

• Inactivated whole virus vaccines
• H9N2 naturally isolated low pathogenic H9N2
  virus
• H5N2 laboratory adapted naturally isolated low
  pathogenic H5N2 virus
• Inactivated reverse genetics vaccines
• H9N2 artificial generated high growth H9N2/PR8
  reassortant virus
• H5N1 artificial generated high growth H5N1/PR8
  reassortant virus
• Live virus vectored vaccines
• H5N1 double recombinant fowlpox virus
• H5 recombinant Newcastle disease virus

18
An ideal vaccine strain should

• Be a low pathogenic strain, safe to the
  environment
• Be able to grow well in eggs, to ensure enough
  antigen in the vaccine product
• Be well matched antigenically with the prevalence
  viruses

19
Molecular modification of the HA gene of GD/96
virus
GD/96 wildtype HA CCT CAA AGA GAG AGA AGA AGA
AAA AAG AGA ? GGA CTA TTT Pro Glu Arg Glu Arg Arg
Arg Lys Lys Arg Gly Leu Phe   Modified HA CCT
CAA CGA GAG ACG CGA ? GGA CTA TTT Pro Glu Arg
Glu Thr Arg Gly Leu Phe   ? Site of cleavage
of into HA1 and HA2 domains. Residues that were
mutagenized are underlined.
R
E
R
R
R
K
K
R
R
E
T
R
20
(No Transcript)
21
Virus titers in chicken embryo
22
HI antibody duration induced by H5 inactivated
vaccines
H5N1
HI antibody titers (log2)
H5N2
Weeks after vaccination
23
One dose inoculation in SPF chickens could
provide 43 weeks protection
24
Does this vaccine work for waterfowls?
25
Vaccine efficacy in geese
26
Vaccine efficacy in Ducks
27
HI antibody duration in geese-field test
HI antibody titers (log2)
Weeks after immunization
Guobin Tian, et al. Virology, 2005, 341 153 162
28
Vaccinated field geese could be completely
protected
29
HI antibody duration in ducks-field test
HI antibody titers (log2)
Weeks after immunization
Guobin Tian, et al. Virology, 2005, 341 153 162
30
Vaccinated field ducks could be completely
protected
31
Avian influenza vaccines in China

• Inactivated whole virus vaccines
• H9N2 naturally isolated low pathogenic H9N2
  virus
• H5N2 laboratory adapted naturally isolated low
  pathogenic H5N2 virus
• Inactivated reverse genetics vaccines
• H9N2 artificial generated high growth H9N2/PR8
  reassortant virus
• H5N1 artificial generated high growth H5N1/PR8
  reassortant virus
• Live virus vectored vaccines
• H5N1 double recombinant fowlpox virus
• H5 recombinant Newcastle disease virus

32
H5N1 AIV
HA NA
Fowlpox virus
HA
NA
Recombinant H5N1 fowlpox virus
33
A recombinant fowlpox virus vectored vaccine is
very well immunogenic in chickens
34
Newcastle disease virus

• Holding great promise as a vector for human
  emerging infectious disease vaccine development
• Very suitable to be a vector for H5 avian
  influenza vaccine development
• Will prevent two list A poultry diseases

35
Generation of a recombinant Newcastle disease
virus with the H5 HA gene
36
The recombinant virus grows as well as the wild
type NDV virus
1010EID50/egg
rLa rLa-H5w rLa-H5m
37
Biological properties of the rescued NDV and
recombinant viruses
38
Protective efficacy against the highly pathogenic
NDV challenge
39
Protective efficacy against highly pathogenic
H5N1 virus challenge
40
Virus shedding of chickens on day 3 p.c.
41
Does this vaccine work for mammalian animals?

• Balb/C mice were vaccinated by intraperitoneal
  injection with two doses of 108EID50 of rLa-H5w
  in a 3 week interval
• Challenged with two HPAIV
• BHG/QH/05 and DK/FJ/02

42
Virus replication in organs of mice on day 3 post
challenge
Virus titers (logEID50)
Nose
Lung
Spleen
Kidney
Brain
Organs
43
Vaccinated with rLa (?, ) or rLa-H5w (?, ?) ,
and challenged with BHG/QH/05 (?, ?) or DK/FJ/02
(?, )
44
Vaccine seed virus generated
45
Summary

• Four major genotype of H5N1 influenza viruses
  were identified in China during 2005-2006.
  Though the viruses showed some degree of
  antigenic variation, the widely used GSGD/96
  virus based vaccine are still effective to three
  groups of the four groups viruses. A Shanxi virus
  based vaccine has been developed and applied in
  the field for the control real antigenic drifted
  viruses. Therefore, the vaccines used in the
  poultry in China have been very well evaluated
  and targeted, and proved to be effective.

46
Acknowledgements

• Dr. R. Webster
• Dr. Y. Kawaoka
• Dr. N. Cox
• Dr. P. Palese
• Dr. G. Brownlee

• Dr. Hualan Chen
• Dr. Zejun Li
• Dr. Guohua Deng
• Dr. Guobin Tian
• Dr. Yanbing Li
• Dr. Yongping Jiang
• Dr. Zhigao Bu

47
Thanks for your attention!