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 overall-planned 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 anti-false 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）

6 6.6%

100-10,000 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 72.5%85.7%

Un-proper vaccination

12 13.2%

vaccinated but had a low titer of antibody

22 14.3%

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!