Transcript Vaccination Campaigns in China

Vaccination Campaigns for
HPAI in China
Huang Baoxu
China Animal Health and Epidemiology Centre
2007.10.17 Beijing
1. Basic Policies
 As speculated by the Law of the People’s
Republic of China on Animal Epidemic
Prevention, China practices the prevention first
policy for infectious animal diseases Control.
 HPAI is classified as the Category I Animal
Disease, China practice the combined
vaccination and stamping-out policy for the
disease.
 After HPAI outbreaks occurred in 2004,
compulsory vaccinations were imposed on
poultry flocks in high risk areas.
 In Oct., 2005, China decided to implement
compulsory vaccination towards all poultry
flocks.
2. Main Practices
2.1 Emphasize on Vaccines Development
 Since 2004, more than 100 million RMB
has been raised to conduct researches
on specific AI vaccines. 6 types of AI
vaccines have been successfully
developed.
 These vaccines can meet different
demands of various poultry breeds.
2.2 Improve quality and supply capacity
 8 well-equipped GMP enterprises were
appointed by MOA to produce AI vaccines.
 All AI vaccines are distributed in an overallplanned way.
 The quality of AI vaccines are guaranteed
through a series of measures including
producing the seed virus by a sole producer,
conducting on-the-spot supervision, carrying
out flying inspection and applying with antifalse labels etc.
 At present, the 8 appointed factories can
provide 16.18 billion doses of inactivated
vaccines and 25 billion doses of live vaccines.
 The total output of AI vaccines in China can
fully satisfy the demand of the domestic
market.
2.3 Standardize the Vaccination Procedure
 MOA has issued 2006
Vaccination Program for
HPAI and 2007 Vaccination
Program for HPAI.
 Given the short raising
period, quick off-take and
restocking characteristic of
poultry production, the
poultry vaccination
program should be
implemented all-year-round.
 All of the scaled poultry farms
must carry out vaccination
according to relative scientific
vaccination procedures;
 Backyard poultry flocks are
subject to the spring-autumn
vaccination campaign;
 Restocked poultry should be
vaccinated every month;
 In case that the importing country
has relevant requirements and
the exporting enterprise has good
animal health conditions, the
poultry are allowed not to
practice vaccination with the
approval of provincial veterinary
administration.
2.4 Increase AI Vaccination Coverage
 China practices compulsory vaccination policy.
In order to reach the goal of 100% coverage for
AI vaccination:
 The AI vaccines are free for the farmers. The
expenses are shared together by the central
and local finance. The central finance will pay
about 1 billion Yuan RMB each year.
 A responsibility system consisting of different
departments and different level governments
are established.
 The salary for veterinaries at the grass-root
has been increased step by step.
 The farmers will be educated through public
awareness program for their active
participation in the vaccination campaign.
 According to the statistics, the vaccinated
poultry in 2006 reached to 10.6 billion, and
more than 95% of the poultry which should be
vaccinated had been vaccinated.
 Until now, the coverage of AI vaccination in
2007 has still been maintained above 95%.
2.5 Strengthen Vaccination Effects Monitoring
 MOA has issued The National AI Surveillance
Program 2005-2010, HPAI Surveillance
Program 2006 as well as HPAI Surveillance
Program 2007.
 Poultry vaccinated with inactivated AI vaccines
should be subjected to antibody test 21 days
after vaccination.
 If the antibody titer is above 4 log2 with HI test,
the result for the poultry should be regarded as
qualified.
 If the qualified rate for a flock is above 70%,
the flock should be regarded as qualified.
Otherwise, the flock must be vaccinated again.
 In 2006, 6.77 million samples were tested, with
the qualified vaccination rate accounted for
86.86%.
Results of serological surveillance in
vaccinated flocks nationwide
CK:87.6%, DK:80.8%, GS:84.12%, Average:86.8%
 The central and provincial laboratories also
launch 2 times of pathogen tests each year
concentrating on breeding poultry farms,
commercial poultry farms and live poultry
markets.
 In 2006, 50 positive samples were confirmed
using RT-PCR test.
 Among these positive samples, the obvious
mutation were found in one strain of AIV from
Yangquan city of Shanxi province. The former
vaccines only can provide 83.3% protective
rate against the virus challenge (H5N2: 5/6;
H5N1:10/12).
 Given this situation, MOA developed a new
vaccine, thus the efficacy has been effectively
safeguarded.
3. Current Challenges
Farming Scale
Outbreaks
Percents
Less than 100
（Backyard）
100-10,000
6
6.6%
80
87.9%
10,000-50,000
5
5.5%
More than 50,000
0
0%
 The scientific and standardized vaccination program
can be easily realized towards flocks of section 1 and
section 2. However, the poultry population of section 3
and section 4 still account for about 60% in China.
There are some difficulties for these poultry flocks
being vaccinated in a standardized and scientific
manner according to the stipulated procedure.
 Veterinaries at county and village level are responsible
for conducting vaccination towards the flocks of
section 1 and section 2. The stocking population of
these kinds of poultry is more than 3 billion in China.
Multiple times of vaccination significantly increases
the workload of them, and also put forward higher
requirements for their qualification.
 The AI virus is liable to mutate. This character put
more challenges for virus monitoring and vaccines
researches.
Vaccination
situation
Outbreaks Percents
unvaccinated
66
Un-proper
vaccination
72.5%
12
13.2%
vaccinated but had 22
a low titer of
antibody
14.3%
85.7%
4. Closing Remarks
 Following the implementation of compulsory
vaccination policies, the HPAI frequency for
China has been decreased each year, which
proved the policy is effective and fit to the
nation’s conditions.
 Prevention with vaccination, Surveillance for
early-warning and Emergency response
constitute China’s HPAI control strategy. The
strategy can’t achieve its success without any
one of these 3 aspects. Vaccination to prevent
is only an important measure for the HPAI
prevention and control campaign.
 Given the large poultry population and relative
back-ward poultry raising mode, the risk for
HPAI occurrence in China still exists.
Thank you for your
attention!