Marek’s Vaccine For Chickens

Chickens are the most important natural host for Marek’s disease virus (MDV), a highly cell-associated but readily transmitted alphaherpesvirus with lymphotropic properties of gammaherpesviruses. Quail can be naturally infected, and turkeys can be infected experimentally. However, severe clinical outbreaks of Marek’s disease in commercial turkey flocks, with mortality from tumors reaching 40%–80% between 8 and 17 weeks of age, were reported in France, Israel, and Germany. In some of these cases, the affected turkey flocks were raised in proximity to broilers. Turkeys are also commonly infected with turkey herpesvirus (HVT), an avirulent strain related to Marek’s disease virus that is commonly used as a Marek’s disease vaccine in chickens. Other birds and mammals appear to be refractory to the disease or infection.

Marek’s disease is one of the most ubiquitous avian infections; it is identified in chicken flocks worldwide. Every flock, except for those maintained under strict pathogen-free conditions, is presumed to be infected. Although clinical disease is not always apparent in infected flocks, a subclinical decrease in growth rate and egg production may be economically important.


Marek’s disease virus is a member of the genus Mardivirus within the subfamily Alphaherpesvirinae. Within the genus Mardivirus are three closely related species previously designated as three serotypes of Marek’s disease virus. Gallid alphaherpesvirus 2 (MDV serotype 1) represents all virulent Marek disease virus strains and is further divided into pathotypes, designated as mild (m), virulent (v), very virulent (vv), and very virulent plus (vv+). Gallid alphaherpesvirus 3 (MDV serotype 2) and Meleagrid alphaherpesvirus 1 (turkey herpesvirus, MDV serotype 3) represent avirulent virus strains isolated from chickens and turkeys, respectively, and are commonly used as vaccines against Marek’s disease.

Storage Conditions

Ampules: store in liquid nitrogen container.

Diluent: store at room temperature.

Liquid nitrogen container: carefully observe all liquid nitrogen precautions including wearing eye protection and gloves. Store in a cool, well-ventilated area. Check liquid nitrogen level daily. Keep container away from incubator intakes and chicken boxes. Caution: do not hold ampule toward face when removing from a liquid nitrogen container. Never refreeze a vaccine ampule after thawing.

Preparation of Marek’s Vaccine For Chickens

1. Dilute the vaccine only as directed, observing all precautions and warnings for handling.

2. Remove from the liquid nitrogen only the ampules that are going to be used immediately. Move quickly, but carefully.

3. Place the ampule(s) in a large, clean container of water at 68° to 86°F (20° to 30°C) to thaw ampule quickly. Thaw the entire contents. Gently swirl the ampule to disperse contents. Break ampule at its neck and quickly proceed as described below.

4. Use 200 ml of sterile diluent for each 1,000 doses of vaccine to be injected subcutaneously or for each 4,000 doses of vaccine to be administered in ovo. Remove the cover from the diluent container. Draw contents of the ampule into a sterile 10 ml syringe fitted with an 18 to 20 gauge needle. Slowly add the contents of the vaccine ampule to the appropriate volume of diluent. Withdraw a small amount of the diluent, rinse the ampule once and add this to the vaccine-diluent mixture. Mix the contents of the diluent container thoroughly by swirling and inverting the container. Do not shake vigorously.

5. Keep the container of diluted vaccine in an ice bath. Use the vaccine-diluent mixture immediately. Agitate as needed to ensure a uniform suspension of the cells.

Features of Marek’s Vaccine For Chickens

Before initiating in ovo vaccination, carefully read and follow the egg injection system operator’s manual. Failure to follow instructions may result in personal injury, embryonic morbidity and mortality.

1. Sanitize the egg injection system before and after use.

2. Inject a 0.05 ml dose into each embryonated egg.

3. Use the entire contents of the vaccine container within one hour after mixing the vaccine with the diluent.


1. Use a sterile automatic syringe with a 20 to 22 gauge 3/8” to 1/2” needle that is set to accurately deliver 0.2 ml per dose. Check the accuracy of delivery several times during the vaccination procedure.

2. Inject chickens under the loose skin at the back of the neck (subcutaneously), holding the chicken by the back of the neck just below the head. The loose skin in this area is raised by gently pinching with the thumb and forefinger. Insert the needle beneath the skin in a direction away from the head. Inject 0.2 ml per chicken. Avoid hitting the muscles and bones in the neck.

3. Use the entire contents of the vaccine container within one hour after mixing the vaccine with the diluent.

2. Swab top of rubber stoppers on dye vial and diluent container with alcohol; let dry.

3. Using a sterile syringe and needle, withdraw the contents of the vial.

4. Inject dye into diluent container and mix well.

5. Only Merial’s Marek’s disease vaccines may be used with this diluent. Add vaccine according to the manufacturer’s recommendations.

Prices of Marek’s Vaccine For Chickens

$19.23 – $80.00

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