ANIMAL AND PLANT HEALTH INSPECTION SERVICE

There are many opinions on whether USDA should use 

vaccine, because doing so would potentially impact the 

ability of our American producers to export poultry 

overseas, an ability that is crucial to the profitability of 

the entire industry. Some trading partners may decide to 

suspend imports from those areas where vaccination is 

used, impacted States, or even the entire country. Also, 

there has been no widely available and effective vaccine.

Decision To Use Vaccination

USDA’s Animal and Plant Health Inspection Service 

(APHIS) has not approved the use of vaccine at this 

time. Before doing so, USDA would take into 

consideration the: 

• extent and rate of spread of the outbreak 

(including the effectiveness of response activities),

• type of poultry operations affected,

• potential impact on domestic and international 

supplies and markets, 

• potential impact on the ability of our American 

producers to export poultry overseas, and

• effectiveness and availability of vaccine.

However, APHIS is taking steps necessary in order to be 

ready to make this decision. This includes reviewing new 

potential vaccines for licensing, stockpiling doses of 

approved vaccines so they would be readily available, and 

completing any required environmental assessments. If 

APHIS approves vaccine use, it would not be used alone.

HPAI and Vaccine Use

The outbreak of highly pathogenic avian influenza (HPAI) H5 in spring 2015 was the worst animal disease 

outbreak in U.S. history. This disease is extremely deadly to chickens and turkeys and caused significant losses 

earlier this year. More than 200 premises were affected in 15 States, with more than 48 million birds depopulated. 

The U.S. Department of Agriculture (USDA), along with State and industry partners, is planning and preparing for 

the possibility that the disease will reemerge this fall and beyond. This includes considering whether to use vaccine 

to help prevent illness in birds and stop or slow the spread of the disease.

Instead, it would be part of a larger, overall strategy 

to contain and eliminate the HPAI virus from the 

United States. While vaccinating, APHIS still would 

focus on enhanced biosecurity and biosurveillance, 

rapid depopulation, and other virus elimination 

methods to help end the outbreak. Ultimately, 

only these actions can achieve total eradication 

and restore the poultry industry to full production 

and exports.

Available Vaccines

To work well, vaccines need to match the genetics of 

the virus. Because avian influenza (AI) viruses are 

adaptable, the genetics can change over time. The 

closer the genetics match to the virus, the more 

effective the vaccine is.

There are AI vaccines currently available, but they are 

not a specific match to the genetics of the current 

outbreak’s virus. Therefore, these vaccines would not 

be sufficient to ensure eradication.

Researchers and vaccine companies are developing 

vaccines that use the genetics from the current HPAI 

virus that caused disease in spring 2015. They are 

studying how much protection the vaccine will 

provide for immunized birds.

APHIS regularly reviews new vaccine options as they 

are developed and submitted for licensing. As 

required by the Virus-Serum-Toxin Act—a law in 

place for over a century—APHIS ensures every 

licensed vaccine is safe, potent, pure, and effective. 
ANIMAL AND PLANT HEALTH INSPECTION SERVICE

To receive a license, a company must test the vaccine on 

the species for which it is seeking licensure.

APHIS would only stockpile and use licensed HPAI 

vaccines that show potential to reduce the spread of the 

virus and death loss. APHIS would then decide which 

vaccines to use, based on the overall needs of the 

disease response.

Vaccine Administration

Vaccines can be administered to poultry in three ways—

by injection, by aerosol mist (breathing in the vaccine), 

or through drinking water. The vaccines currently 

approved or being researched are all injectable-type 

vaccines. 

Vaccine could be administered to hatching eggs or to 

day-old chicks. Immunity to the virus develops in about 

21 days. Depending on the bird’s lifespan, a booster dose 

may be necessary. Turkeys would likely receive at least 

one booster dose, while layer chickens may need two or 

more booster doses. Broiler chickens have much shorter 

lifespans—around 40 days—so vaccinating them would 

not be as useful.

Limits of Vaccine

It is important to understand what HPAI vaccine would 

and would not do. 

HPAI vaccines reduce sickness, clinical signs, and death in 

domestic poultry. They would not prevent birds from 

becoming infected with the AI virus or from producing 

and shedding virus into the environment. Vaccine would, 

however, reduce the amount of virus an infected bird 

sheds into the environment, which in turn helps prevent 

spread to new locations. 

USDA would carefully target where to use vaccines; they 

would not be used on a widespread basis. Limiting 

vaccination to some areas and some species would offer 

the best chance of limiting crippling export sanctions. 

Producers would not be able to obtain vaccine from 

their veterinarian and proactively vaccinate their birds. 

Only USDA and State veterinarians would authorize 

vaccine use and monitor its administration. 

USDA is an equal opportunity provider and employer. 

APHIS 91-85-007

Issued December 2015

After Vaccination

Producers would not be allowed to move vaccinated 

birds outside of the vaccination area, unless the shipment 

was sent directly to slaughter under a permit from 

State or Federal animal health officials. Products from 

vaccinated birds could only be moved and used within 

the United States. 

Animal health officials would regularly monitor and test 

vaccinated flocks for HPAI infection. If they find infection, 

APHIS would depopulate the flock and provide 

indemnity to the producer. APHIS would also work with 

producers to closely track all vaccinated birds through 

their normal lifespans to confirm when they are 

removed from the U.S. poultry population. 

If there are indications that the vaccine strategy is 

not working to help contain the disease, APHIS would 

re-evaluate the use of vaccine. Finally, APHIS would 

stop vaccination after the outbreak is contained and 

HPAI eradicated. Once all vaccinated birds were 

removed from the U.S. poultry population, APHIS 

could re-declare the United States HPAI-free 

without vaccination.

 FOR MORE INFORMATION

 To learn more about HPAI and emergency response and find 

 helpful resources on these topics, go to:

• www.usda.gov/avian_influenza.html 

• www.aphis.usda.gov/fadprep