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Optimal immunization of your dairy herd: More than just vaccination

Elizabeth Doré for Progressive Dairy Published on 16 March 2021

We often take vaccination for granted and think it’s just something we have to do, but we don’t necessarily stop to think about what we are trying to achieve. By vaccinating your cows, you want to keep your herd healthy by preventing some infectious diseases, as well as ensuring productivity and profitability.

To put things in perspective, the term “vaccination” refers to the act of giving the vaccine. To protect our herd, immunization is the end goal we are looking to achieve when vaccinating. According to the World Health Organization (WHO), immunization is the process whereby a person (or animal) is made immune or resistant to an infectious disease, typically by the administration of a vaccine.

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When designing your vaccination program with your veterinarian, there are many aspects to take into account before giving a shot or squirting something up the nose. The first question to ask is: What are the diseases from which your herd should be protected with vaccination? Unlike horses, dogs and cats, there is not a recognized core vaccination guideline for cattle. Fetal protection against bovine viral diarrhea virus (BVDV) and infectious bovine rhinotracheitis virus (IBR), and protection against some viruses causing respiratory diseases would be considered the basis for a dairy cattle vaccination protocol.

The purpose of this article is not to review all available vaccines for cattle, but know there are vaccines available to protect from viruses and also bacteria. You should discuss with your veterinarian what type of protection is offered by vaccines against these specific diseases. Vaccines don’t necessarily prevent the infection from occurring, but with the immunity they provide, duration and severity of disease can be decreased.

Vaccines contain one or more specific antigens that won’t cause disease but to which the immune system will mount an immune response. This means a specific immune response for that antigen will be elicited, but you can’t expect to prevent a disease with multiple etiology. For example, when vaccinating to aid in preventing abortion caused by IBR, you can’t expect the vaccine to prevent all possible causes of abortion.

Keep in mind: A vaccine is to be used as part of a broader control program. For example, vaccination against BVDV on its own won’t be as helpful if persistently infected animals are not identified and removed from the herd, and without biosecurity measures when introducing new animals in the herd (i.e., BVD testing). Vaccination can be helpful in managing neonatal diseases such as diarrhea caused by specific pathogens, but it’s crucial to work on husbandry aspects as well (colostrum, nutrition, hygiene, stocking density, etc).

The second step in designing your vaccination protocol is to review with your veterinarian the details on where and when the vaccines will be given. It is important to carefully read the vaccine labels and make sure the right dosage is given (how many millilitres are needed and if a booster dose is required) at the right site (intramuscular, subcutaneous, oral or intranasal).

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The timing of vaccination should also be determined. How soon can the vaccine be given to cows after calving? Cows during the transition period experience systemic immune suppression; therefore injectable vaccines should be given at least three weeks postpartum. Can the vaccine be given to pregnant cows? Modified-live vaccines cannot be given to pregnant cows if they were not properly immunized previously, according to label directions. At what age can a calf be vaccinated? For vaccination against BVDV, calves should be vaccinated after 6 months old to overcome interference with maternal antibodies. Avoid vaccinating on a very warm and humid day or schedule your vaccination early in the morning, before it gets too hot, to reduce the chance of adverse reactions.

Storage and handling of vaccines are essential to preserve their efficacy until administration and to ensure optimal immunization. These aspects should also be reviewed with your veterinarian and be part of your vaccination protocol.

Storage

Vaccines should be stored between 2ºC and 8ºC from the time they leave the manufacturer to the time of administration. Lack of adherence to proper temperature guidelines may result in lack of vaccine effectiveness, undue vaccine failures and an increased rate of local reactions after vaccine administration. Make sure to keep vaccines with ice packs on your way back from the veterinary clinic.

If you are not vaccinating your cows right away, store them in the refrigerator on arrival. To avoid variations in temperature, vaccines should be stored in the middle of the refrigerator. Don’t store them in the door, where temperature fluctuates the most, or against the back of the refrigerator, where they can freeze. You can keep a thermometer in the refrigerator to monitor temperature regularly.

It’s important to ensure vaccines do not freeze, especially killed vaccines. Freezing can occur unknowingly by placing vaccines directly on cold packs or in fridges that are too cold. Crystals can form in the adjuvant; disturbance in its structure will affect immune response to the antigen and consequently diminish vaccine efficacy. The frozen adjuvant could also lose its property of binding to toxins, and this can result in a higher rate of adverse reactions. To avoid this from happening, place a towel or a newspaper between the vaccine bottles and the ice packs or leave the bottles in their cardboard box.

Handling

Prolonged exposure to higher temperatures and direct sunlight should be avoided when administering the vaccine. Place vaccines in a cooler with ice packs during the herd health visit. Don’t leave them beside the computer or in your pocket.

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Modified-live vaccines should be reconstituted before use by gently mixing the liquid portion with the freeze-dried portion. If you “shake” too vigorously, some constituents might be damaged or destroyed. To avoid vigorous shaking, you should roll the bottle between your hands.

Once a modified-live vaccine is reconstituted, it must be used within two hours and still be maintained between 2ºC and 8°C. As a practical recommendation, you should only reconstitute as much vaccine as you need for the next 30 minutes.

Materials

Sterilized syringes and needles should be used to administer vaccines. Never insert a used needle into a bottle, as contamination could occur. Using a new sterile needle for each cow will prevent transmission of blood-borne diseases, like bovine leukosis.

Do not sterilize your syringes and needles with chemicals because traces of disinfectant may inactivate the vaccine. If you use a syringe gun, only use very warm water to clean it. Soap residues or alcohol can inactivate the vaccine next time you use the gun.

Now that you know which vaccines you will use to immunize your herd, how to use them and properly store them, you need to review with your veterinarian what should be done in the face of an adverse reaction following vaccination. Anaphylaxis may occur after use of vaccines. If your veterinarian is not at the farm when you are administering vaccines, it is important to know how to recognize the associated signs and what to do when such a reaction occurs.

You might want to keep epinephrine on hand with needle and syringe ready to go and have knowledge of the dose that is required. If such a reaction occurs, treat the animal first, then call the veterinarian to seek advice, as supportive therapy might be required. Keep in mind: Both your herd veterinarian and the product manufacturer want to know if an animal suffers a suspected adverse reaction following administration of a vaccine or of any veterinary product. Reactions should always be reported to the manufacturer.

You are now ready to properly immunize your dairy herd. Make sure to review your vaccination protocol periodically with your veterinarian and to train your employees on a regular basis.  end mark

References omitted but are available upon request. Click here to email an editor.

Elizabeth Doré is a manager with veterinary services at Zoetis Canada. Email Elizabeth Doré.

How to develop vaccine protocols to ensure proper immunization

  • Discuss with your veterinarian to determine which diseases your herd should be vaccinated against.

  • Combine vaccine protocols with other control measures, such as biosecurity, for more comprehensive control.

  • Carefully read vaccine labels and ensure the correct dosage is given.

  • Understand when vaccines should be given and if they are safe to use on pregnant cows.

  • Maintain vaccine effectiveness by storing them between 2ºC and 8°C, and do not let them freeze.

  • Always use sterilized syringes and needles, but avoid the use of chemicals to sterilize as they may inactivate the vaccine.

  • Work with your veterinarian to develop a plan in case of adverse reactions to vaccination. 

  • Once vaccination protocols are developed, review them periodically and make sure they are followed by all employees.

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