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Chicken Vaccination: What You Need to Know 

chicken vaccination

There’s a lot of discourse on which chicken vaccination is necessary and how helpful they really are.

In this guide, we hope to clarify things for you by giving an unbiased look at your different options.

We will also cover situations when vaccines are helpful and when they are not needed.

In some cases, you might need one chicken vaccination or several for the best immunity.

So, let’s get into it!

Chicken Vaccination: Do I Have to Vaccinate My Chickens?

There are no legal mandates that require you to vaccinate your flock.

Many shows, clubs, fairs, and other poultry organizations require specific vaccinations.

However, chicken vaccinations are also not required for backyard keepers who will not take their birds off the property.

To cross state lines and international borders, you will need proof of vaccination (and usually a health certificate).

When Should You Not Do Chicken Vaccinations?

There are a few circumstances when you should absolutely not vaccinate your chickens. These situations are:

When you are raising broilers for meat

These chickens have a shorter lifespan than the withdrawal period, so it is not possible for you to safely vaccinate and then consume the birds’ meat.

When you have older chickens that are due to be culled

For similar reasons as the broilers (or fryers), you have to let chickens have that withdrawal period to get the vaccines worked out of their body.

When you are unable or unwilling to toss the eggs

If you have a laying hen, you must dispose of those eggs for however long the vaccine manufacturers recommend.

When you have only one hen whom you want to vaccinate but do not separate her from the flock, you’ll need to dispose of all eggs out of caution.

If you are unable or unwilling to do this, skip the vaccines.

When chickens are already sick, stressed, or underweight

The vaccines are not effective if your chicken is not in good health.

Focus on getting them in better condition before moving on to the vaccines.

If you want to run a vaccine-free farm

Some chicken producers are focused on breeding out the “need” for vaccines.

In these programs, breeders avoid vaccines and use survival of the fittest to continue their breeding program.

Sick birds fight it and get better or pass away, while healthy ones continue on.

Note: Do not vaccinate for diseases or illnesses that are not already common in your area.

Vaccinating unnecessarily brings new organisms to a flock that could be potentially dangerous.

chicken vaccination

When Is It a Good Idea for Chicken Vaccinations?

Vaccines have proven effective in preventing or reducing the effects of certain illnesses or diseases in chickens.

Vaccines are strongly recommended for the following situations:

  • Bringing chickens on and off your property repeatedly.

Fairs, shows, auctions, sale barns, etc., are all examples of easy ways for your chickens to contract new diseases.

Vaccinating protects traveling individuals, your home flock, and all the other birds they may meet while on the road.

  • Areas with heavy disease risk.

If you know that your area has an issue with a disease or two, you should at least consider inoculating your flock against those issues.

  • Properties with heavy foot traffic.

If you run a farm stand or petting zoo or regularly welcome visitors onto your property, your chickens are at a greater risk.

The chickens can easily pick up issues from your visitors’ hands, shoes, and clothing.

This is especially true for visitors with farms of their own or people who may have visited another farm prior to yours.

Where To Get a Chicken Vaccination

While most pets and livestock need a veterinarian’s assistance to be vaccinated, many poultry vaccines are available online.

Some of these vaccines will need veterinary office approval.

If you have a good relationship with your local veterinarian, they can sometimes write the prescription they need over the phone, rather than having to visit you or lug your flock into them.

It’s also possible that your hatchery will vaccinate day-old chicks on your behalf before shipping them to you.

Here are some of our top recommendations for finding vaccines online:

chicken vaccination

Chicken Vaccination: Most Commonly Used Vaccines

  • Marek’s Disease Vaccine. Protects against Marek’s disease, a highly contagious viral infection that affects chickens.
  • Infectious Bronchitis Vaccine. Guards against infectious bronchitis virus, which causes respiratory illness in chickens.
  • Newcastle Disease Vaccine. This vaccine works against Newcastle disease, a viral infection that can cause respiratory, nervous, and digestive symptoms in chickens.
  • Avian Influenza Vaccine. It helps prevent avian influenza, a viral disease affecting birds’ respiratory, digestive, and nervous systems. This vaccine is still being tested by the USDA but may be more widely available soon. There is also a vaccine for humans.
  • Infectious Bursal Disease (Gumboro) Vaccine. This vaccine protects against the infectious bursal disease virus, primarily affecting chickens’ immune systems.
  • Fowl Pox Vaccine: This vaccine works against fowl pox, a viral disease characterized by skin lesions and sometimes respiratory symptoms.
  • Salmonella Vaccine. Helps prevent Salmonella infections in chickens, which can also be transmitted to humans through contaminated eggs or poultry products.
  • Coccidiosis Vaccine. Aids in preventing coccidiosis, a parasitic disease affecting the intestinal tract of chickens.
  • E. coli Vaccine. This vaccine protects against certain strains of Escherichia coli bacteria, which can cause respiratory and systemic infections in chickens. This fascinating study was conducted on broilers, which we’ll cover in more detail below.
  • Mycoplasma gallisepticum Vaccine. Wards off mycoplasma gallisepticum, a bacterial infection causing respiratory symptoms in chickens and turkeys.

I’ll cover these diseases and their vaccines over the next segment.

Marek's disease

Marek’s Disease Chicken Vaccination

Marek’s disease, first identified in the early 20th century by Hungarian veterinarian Jozsef Marek, emerged as a pressing concern for poultry producers globally.

The disease is caused by Marek’s disease virus (MDV), a member of the Herpesviridae family, specifically Gallid alphaherpesvirus 2.

MDV primarily targets chickens, causing tumors, paralysis, and immunosuppression, leading to discomfort and death for the bird– and substantial economic losses in the poultry industry.

The Marek’s disease vaccine operates by stimulating the bird’s immune system to recognize and defend against MDV upon exposure.

Traditionally, live attenuated vaccines have been used to confer protection.

These vaccines contain weakened strains of MDV that induce an immune response without causing disease.

Additionally, newer vaccines, such as recombinant vaccines, utilize modern biotechnological approaches to enhance efficacy and safety.

This vaccine immediately prompts the production of specific antibodies and cellular immunity against MDV antigens.

This immune memory equips chickens with the ability to neutralize the virus upon encounters, preventing the disease’s manifestation.

It is not dangerous to the chicken.

Types of Vaccines for Marek’s Disease

Several types of Marek’s disease vaccines are available, each with distinct characteristics and modes of administration.

  • HVT (Herpesvirus of Turkeys)-based vaccines. These vaccines use a non-pathogenic strain of HVT virus to deliver MDV antigens, conferring protection against Marek’s disease.
  • SB-1 (Serotype 1) vaccine. SB-1 is a live attenuated vaccine strain of Marek’s disease virus, widely used for vaccination in commercial poultry flocks.
  • Recombinant vaccines. Recombinant technologies enable the development of vaccines containing specific MDV antigens, enhancing vaccine safety and efficacy.
  • Vector vaccines. These vaccines utilize non-pathogenic viruses or bacteria as vectors to deliver MDV antigens to the host’s immune system, eliciting a protective response.

The two most common/commercialized Marek’s Disease Vaccines are:

  • MD-Vac CFL
  • CVI988/Rispens

Be sure to read our guide, All You Need to Know About Marek’s Disease.

ALSO READ: Marek’s Disease in Chickens Is 100% Preventable

Infectious Bronchitis Vaccine

Infectious bronchitis was first identified in the 1930s, with subsequent research revealing it as a highly contagious respiratory disease primarily affecting chickens.

The causative agent, infectious bronchitis virus (IBV), belongs to the Coronaviridae family, specifically the genus Gammacoronavirus.

IBV manifests as respiratory distress, decreased egg production, and poor growth rates in infected birds, posing considerable challenges to the poultry industry.

The infectious bronchitis vaccine operates by priming the avian immune system to recognize and defend against IBV upon exposure.

Typically, live attenuated vaccines contain weakened strains of IBV that induce protective immunity without causing disease.

Inactivated vaccines, which consist of inactivated IBV particles, are also sometimes used to give better immunity against specific strains of the virus.

The chicken has humoral and cellular immune responses upon vaccination, producing antibodies and activated immune cells that target those IBV antigens.

Types of Vaccines for Infectious Bronchitis

Several types of infectious bronchitis vaccines are available, each offering unique advantages.

  • Live attenuated vaccines. These vaccines contain weakened strains of IBV, providing broad-spectrum protection against multiple virus variants.
  • Inactivated vaccines. Inactivated vaccines utilize killed IBV particles to elicit protective immunity against specific strains of the virus.
  • Recombinant vaccines. Recombinant technologies enable the development of vaccines expressing specific IBV antigens, enhancing vaccine safety and efficacy.
  • Combination vaccines. Some vaccines combine antigens from multiple respiratory pathogens, offering comprehensive protection against infectious bronchitis and other respiratory diseases.

To ensure early protection, infectious bronchitis vaccines are typically administered to chicks at a young age—usually under 21 days old.

Common IB vaccine options:

Be sure to read our guide on Infectious Bronchitis in Chickens.

Marek's disease

Newcastle Disease Vaccine

Newcastle disease, named after its initial identification in Newcastle upon Tyne, England, in 1926, is caused by the Newcastle disease virus (NDV), a member of the Paramyxoviridae family.

The disease manifests with a wide range of symptoms, including respiratory, nervous, and digestive signs, leading to global economic losses in the poultry industry.

The Newcastle disease vaccine operates by priming the bird’s immune system to recognize and combat the Newcastle disease virus upon exposure.

Vaccines stimulate the production of specific antibodies and cellular immunity against NDV antigens, making the chickens less likely to be affected by it.

Common vaccine administration methods include drinking water vaccination and intramuscular or subcutaneous injection of day-old chicks or older birds.

Newcastle is most effective when given on day one of life. Weeks 2-4 are the next most effective times, followed by four weeks old.

Adult birds can be vaccinated as often as once every six months.

Be sure to read our guide, Newcastle Disease In Poultry: What It Is, and Why There Was A Massive Culling of Poultry in California.

Avian Influenza Vaccine

Avian influenza, commonly known as bird flu, is a highly contagious viral infection that is a global issue. The first description dates back to 1878 Italy.

The first human outbreak happened in 1997 in Hong Kong. Though it is likely that it existed before then, it just wasn’t recorded.

The virus responsible for avian influenza belongs to the Orthomyxoviridae family, primarily subtypes H5 and H7, which can cause severe disease in poultry, leading to potentially devastating zoonotic risks.

While it is relatively normal to have one or two dead or dying birds (especially in larger operations), you must be concerned if larger populations start declining all at once.

This is a good indicator of avian influenza; you should contact your local extension office immediately.

Common methods of vaccine administration include spray vaccination and in ovo vaccination, which involves administering vaccines to developing embryos before hatching.

Proper vaccine storage, handling, and administration techniques are essential to ensure vaccine efficacy and maximize protective immunity.

As of 2023, the USDA is testing several avian influenza vaccines against highly pathogenic avian influenza (HPAI) to prevent the largest bird flu outbreak.

AVMA.org says “Common Avian Influenza vaccines are: While four vaccines are licensed for avian influenza—HA subtype, H5N1, H5N3, and H5N9—none are approved for the more virulent strain, H5N1 clade, found in the current outbreak.”

  • Flosure XP

Be sure to read our guide, Backyard Chickens and Bird Flu.

chicken vaccine chicken vaccination

Infectious Bursal Disease (Gumboro) Vaccine

Gumboro disease, also known as an infectious bursal disease (IBD), is highly contagious and should be vaccinated against if it is known to be in your area (all throughout the US).

Gumboro disease was first identified in the 1960s in Gumboro, Delaware, United States, hence its name.

It is caused by the infectious bursal disease virus (IBDV), which is a member of the Birnaviridae family.

Gumboro disease outbreaks can result in significant mortality rates, immunosuppression, and decreased production efficiency in poultry flocks.

Dr. Daral Jackwood of The Ohio State University, Ohio Agricultural Research and Development Center in Wooster, Ohio, says, “There are hundreds of thousands of cases in this country every year.

It’s present in nearly every large commercial poultry operation,”

Unfortunately, it is easy to spread and nearly impossible to stop, which is why prevention and vaccination is so important.

It does not respond to disinfectants, it’s easily spread by wild birds, dirty shoe soles, feed, manure, and researchers don’t even know how long it is viable in the soil.

Because of this, they recommend storing poultry manure for at least six months before spreading.

Chicks are most vulnerable around one-month-old, so they should be vaccinated at a few days old.

Chicks who contract IBD are more likely to be immunosuppressed and eventually die of the other mentioned diseases on this list, especially Mareks and Infectious Bronchitis.

The most common IBD Vaccines are:

  • Bursine-2
  • Nobilis Gumboro D78
  • Nobilis® Gumboro 228E

fowl pox in chickens

Fowl Pox Vaccine

Bollinger first discovered Fowl Pox in 1873, and the first vaccine was released 45 years later, in 1918.

Fowl Pox is usually spread by mosquitos, which is why cleanliness and biosecurity practices aren’t always enough. It’s classified as a mild to severe poultry disease.

Affected chickens and turkeys have blisters on their wattles, comb, and face, and occasionally these blisters will spread to other areas of their bodies.

Most of the time, these blisters heal, scab up, and fall off within a month.

Many birds will have lifelong scars, but these are typically just cosmetic issues.

It also causes weight loss, stunted growth, and significant drops in egg production.

The Fowlpox vaccine is most effective when administered at 2.5 to 3 months old (10 to 12 weeks).

The most common Fowlpox vaccines are:

  • AE-Poxine
  • HYGIEIA Fowl Pox Vaccine
  • PP-VAC

Be sure to read our guide, Fowl Pox in Chickens: Symptoms, Treatment, and Prevention.

Salmonella Vaccine

Salmonella is a genus of bacteria commonly associated with foodborne illness in humans and animals.

These bacteria can cause various symptoms, from mild gastroenteritis to severe and potentially life-threatening infections.

There are many different serotypes, or variations, of Salmonella bacteria, with Salmonella Enterica being the most common species responsible for causing illness in humans.

Salmonella Typhimurium and Salmonella Enteritidis are most commonly associated with foodborne outbreaks.

Salmonella bacteria typically live in the intestinal tracts of chickens (and other animals) and do not usually cause illness.

However, if humans consume contaminated animal products such as poultry, eggs, meat, or unpasteurized dairy products, the bacteria can cause infection.

Symptoms and Risk of Salmonella

Symptoms of salmonellosis, the illness caused by Salmonella infection, often include diarrhea, abdominal cramps, fever, nausea, and vomiting.

These symptoms usually develop within 6 to 72 hours after consuming contaminated food or water and can last for several days to a week.

In severe cases, this disease is particularly in vulnerable populations such as infants, elderly individuals, and those with weakened immune systems.

Salmonella infection can lead to complications such as dehydration, bloodstream infections (bacteremia), and reactive arthritis.

A biologist at Washington University in St. Louis developed the first salmonella vaccine in 1998, originally called “Megan™Vac 1”.

This vaccine is sprayed on new chicks and grants immunity, a huge breakthrough for commercial farms.

Flocks moved from 50% positive testing rates (in the 1980s) to 10% (in the late 90s). As of 2020, the average commercial infection rate is 0-1.8%.

Even though Salmonella is one of the most common causes of bacterial food-borne diseases in humans, vaccines aren’t as popular as you’d assume.

The vaccines themselves are highly effective, but the issue is that commercial farms have residual dust, feces, and loose soil that act as reservoirs for salmonella, allowing its reintroduction.

Another obstacle is that rats, insects, and even people can transmit salmonella to chickens.

This interesting study from 2020 on PubMed goes into even more depth on these challenges and what is being done to correct them.

Most common types of Salmonella Vaccines:

  • Vaxsafe ST
  • AviPro Megan Vac 1
  • Poulvac ST

Check out these two guides, Salmonella in Chickens: Causes, Signs, and Prevention, and No More Salmonella Recalls: New Technology Revealed

Coccidiosis In Chickens

Coccidiosis Vaccine

Coccidiosis is a common and potentially serious intestinal disease that affects chickens and other poultry species.

It is caused by protozoan parasites from the genus Eimeria, specifically several species within this genus.

These parasites invade the cells lining the chicken’s intestinal tract, leading to tissue damage, inflammation, and potentially severe health consequences—including death.

Coccidiosis is an issue with rabbits, goats, cattle, and several other poultry species, but thankfully, it is not known to jump between species.

Coccidiosis primarily spreads through ingesting sporulated oocysts, the environmentally resistant form of the parasite found in feces.

Chickens become infected when they consume feed, water, or litter contaminated with these oocysts.

Once ingested, the oocysts release sporozoites, which then invade the cells of the chicken’s intestinal lining, where they undergo multiplication and further development.

The severity of coccidiosis can vary depending on factors such as:

  • the species and strain of Eimeria involved
  • the age and immune status of the chickens
  • environmental conditions
  • management practices

Young chickens, particularly those between 3 and 6 weeks of age, are most susceptible to severe forms of the disease.

Coccidiosis Symptoms

Symptoms of coccidiosis in chickens can include:

  • Diarrhea may range from mild to severe and may contain blood or mucus.
  • Poor growth and weight gain.
  • Reduced feed intake.
  • Lethargy and weakness.
  • Ruffled feathers and huddling behavior.
  • Dehydration.
  • In severe cases, coccidiosis can lead to mortality, especially in young or immunocompromised chickens.

Types of Coccidiosis Vaccine

The first live coccidiosis vaccine was COCCIVAC , which came out in 1952.

Most Coccidiosis vaccines will prevent against eight precocious strains for maximum efficacy.

You’ll need to administer Coccidiosis vaccines between day 14 and day 21, not a day before or after.

The most common Coccidiosis vaccines include:

Be sure to read Coccidiosis in Chickens – How To Identify And Treat, plus the goat guide- Coccidiosis in Goats: Symptoms, Treatment & Prevention.

Chickens in a poultry farm

E. Coli Vaccine

Escherichia coli (E. coli) is a bacteria that naturally inhabits the intestines of chickens and other animals. Many animals and birds have trace amounts of it naturally.

While many strains of E. coli are harmless and beneficial, some strains can cause illness in chickens under certain conditions.

Types of E. coli Infections in Chickens

In poultry, E. coli infections can manifest in various ways, including respiratory, gastrointestinal, and systemic infections.

Here are some common types of E. coli infections in chickens.


This is a general term used to describe E. coli infections in poultry.

Colibacillosis can manifest as a range of symptoms, including respiratory signs such as coughing and sneezing, as well as diarrhea, decreased egg production, and lameness.

In severe cases, colibacillosis can lead to systemic infections and mortality.

Respiratory Colibacillosis

Chickens may develop respiratory infections due to certain pathogenic strains of E. coli.

These infections can lead to symptoms such as nasal discharge, difficulty breathing, and swollen sinuses.

Respiratory colibacillosis is often associated with poor ventilation and crowded conditions in poultry houses.

Avian Pathogenic E. coli (APEC)

Some strains of E. coli are classified as avian pathogenic, meaning they can cause disease in poultry.

APEC strains can lead to various infections, including respiratory infections, septicemia (bloodstream infections), and localized infections such as cellulitis and omphalitis (inflammation of the navel).

Enteric Colibacillosis

This form of E. coli infection primarily affects the gastrointestinal tract of chickens.

It can cause symptoms such as diarrhea, dehydration, and poor growth.

Enteric colibacillosis is often associated with factors such as poor sanitation, contaminated water or feed, and stress.

Common E. Coli Vaccines, Treatment & Prevention

The prevention and control of E. coli infections in chickens involve good flock management, especially steps to reduce stress and minimize exposure to potential sources of infection.

This includes maintaining clean and dry housing conditions, providing clean water and feed access, practicing good biosecurity measures, and avoiding overcrowding.

In cases where E. coli infections occur, treatment may involve using antibiotics under veterinary supervision.

The withdrawal period has to be respected, too, which, unfortunately, is sometimes longer than the lifespans of many commercial meat birds.

In these instances, the birds have to be destroyed and discarded. Because of this, vaccination is a huge benefit.

The most common E. Coli Vaccines:

  • Poulvac E. Coli
  • Enviracor

Ensure you read 4 Diseases Humans Get from Backyard Chickens: Zoonotic Diseases and Amoxicillin for Chickens.

Marek's disease

Mycoplasma Gallispecticum Vaccine

Mycoplasma gallisepticum (MG) is a bacterium that causes chronic respiratory disease (CRD) in chickens and infectious sinusitis in turkeys.

It is a member of the class Mollicutes, which is characterized by its lack of a cell wall and small genome size.

This bacterium primarily infects the respiratory tract of chickens, leading to respiratory signs and decreased production performance.

It can also cause conjunctivitis, sinusitis, and other nasty secondary infections.

MG transmits through direct contact between birds, aerosol transmission, and vertically from infected hens to their offspring.

Once a flock is infected, the bacterium can persist within the bird population for extended periods, leading to chronic, low-grade respiratory disease.

Symptoms of the MG infection in chickens may include:

  • Sneezing
  • Coughing
  • Nasal discharge (clear, white, yellow, green, black, or brown)
  • Swollen sinuses
  • Watery eyes or conjunctivitis
  • Decreased feed intake
  • Reduced egg production and poor egg quality

Vaccination against Mycoplasma gallisepticum is commonly practiced in commercial operations and sometimes even on small—to medium-sized farms.

Vaccines are administered to breeding stock to help prevent vertical transmission to offspring or to commercial flocks to reduce clinical signs and production losses.’

The first MG vaccine, created for the F-strain, was made and approved by the USDA in 1988.

Common MG vaccines include:

  • MG-Bac

Take a moment to read this guide, The Chicken Respiratory System (And Common Diseases).

Chicken Vaccination: Final Thoughts

Every farm, region, and flock is different, meaning there is no one-size-fits-all approach to vaccinating your flock.

Depending on your area, goals, operation style, and personal views, you may need one kind of chicken vaccination, several vaccines, or none at all.

Currently, the most popular (and necessary) chicken vaccinations in the US are for Marek’s Disease, Fowl Pox, and Infectious Laryngotracheous.

We hope this was helpful and wish you the best on your chicken-keeping journey.


One thought on “Chicken Vaccination: What You Need to Know 

  1. I heard somewhere that the Avian Influenza Vaccine will test positive for the virus resulting in the bird being held for ‘study’ or ‘un-alived’ during an outbreak is this true?

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