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Intranasal vaccines provide faster protection against disease threats

Scott Nordstrom for Progressive Dairyman Published on 06 May 2019

Calves are the future of your dairy. Using the tools available to build a calf’s immunity within the first days and weeks of life can help set them up for a lifetime of production. Building an effective vaccination protocol can help calves through times of stress and help them be more resistant to the harmful pathogens encountered throughout life.

Calves are born with a developing, but not yet fully functioning immune system. Without vaccinations, they are reliant on passive immunity from maternal antibodies they receive through colostrum for disease protection. Maternal protection is critical, but is limited by the intake and quality of colostrum.

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Because maternal antibodies are unpredictable, it’s difficult to know the amount a calf receives, the specific disease those antibodies target and the duration a calf will be protected through passive immunity.

Build immunity before a disease challenge

Having a well-executed vaccination program on your dairy is important so that an immune response can be developed before animals face disease challenges. For several decades, we assumed vaccinating calves at an early age was ineffective as the maternal antibodies would neutralize antigens introduced by the vaccine. This process is referred to as maternal antibody interference.

Injectable vaccines deliver a modified virus that presents a challenge to help an animal start building its own immunity against a disease. While this is very effective in older animals, these vaccines may be less effective in young calves. Colostral antibodies may bind with vaccine antigen, reducing their ability to create a normal immune response.

A calf’s best defense against disease is making sure proper animal husbandry processes are in place, proper colostrum is delivered and then waiting until calves are a few months old to vaccinate. Practices such as cleanliness and separating challenged animals remain important to a young calf’s survival.

But thanks to research done by Dr. Philip Griebel, professor and research chair in neonatal mucosal immunology at the University of Saskatchewan School of Public Health, we now know the mucosal immune system, which is part of the upper respiratory tract, in newborn calves is functional and excluded from the effects of colostrum immunity that would interfere with vaccination.

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Griebel’s discovery gives us confidence in an effective way to begin putting protective immunity in place within three to four days of vaccination and also stimulates nonspecific immunity at the mucosal surfaces that help to provide protection against pathogens not found in the vaccine. Intranasal vaccines are effective in young calves because the antigen is introduced in close proximity to the mucosal surfaces that are loaded with immunological active tissues.

As a result of this discovery, it’s possible to avoid interference with maternal antibodies by using quality intranasal vaccines, which will begin to put protective immunity in place within three to four days. They will also stimulate nonspecific immunity at the mucosal surfaces, which help to provide protection against pathogens not found in the vaccine. This provides more assurance calves will be capable of handling exposure to infectious agents.

The new gold standard

Research suggests a two-pronged approach to providing early protection for calves. The new gold standard for young calf care includes administering intranasal vaccines during the first few days of its life and following up with a booster dose at approximately 6 weeks of age.

Following the two-step intranasal vaccination process with a broader-spectrum injectable vaccine when calves are approximately 4 months old provides two layers of defense.

Previously, we relied on maternal antibodies as the sole protection against early diseases like scours and pneumonia. Now that we know intranasal vaccines stimulate an immune response in young animals, dairies can provide protection through the critical neonatal period.

Immune memory is a powerful tool

Through the use of vaccines, the immune system recognizes an antigen an animal has previously encountered and initiates a combative response to enhance herd disease protection. Building an immune memory provides animal caretakers with a valuable and powerful way to enhance disease protection.

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For example, a high-risk period for calves contracting pneumonia is during their third week of life – between 21 and 28 days. Young calves are especially vulnerable during this period because the power of maternal antibodies has begun to wane, and it can take three to four weeks before protective immunity is achieved from injected modified-live virus vaccines. However, intranasal vaccines put protective immunity in place within three to four days and also stimulate nonspecific immunity at the mucosal surfaces that help to provide protection against pathogens not found in the vaccine.

Furthermore, testing of nasal secretions revealed that calves receiving a modified-live virus vaccine administered through the nostrils early in life start to produce a type of antibody called IgA within 10 to 12 days.

By extending the window at which a calf produces antigens similar to those in maternal antibodies, dairy producers can shorten the window calves are susceptible to disease threats. Building a robust immune system improves the health and future of the dairy herd.

Talk with your veterinarian to determine if intranasal vaccination is right for your operation.  end mark

Scott Nordstrom
  • Scott Nordstrom

  • Associate Director of Ruminant - Life Cycle Management
  • Merck Animal Health
  • Email Scott Nordstrom

The proper technique for intranasal vaccination

When using live agents like intranasal vaccines, it’s important to use the product within about an hour after mixing. Follow the product’s label directions for the dose, as well as how to mix and administer.

After mixing, load the dose in a syringe or set up a multidose tool. Instead of using a needle, use a 2-inch-long plastic tube or cannula with a depth-control ring or tab, and insert the tube into the calf’s nostril.

For the intranasal vaccine to be effective, the intranasal mucosal surfaces must come in contact with the fluid. This is easier to achieve in young calves, as they are less resistant to having their head restrained so the vaccine can run into the nostril.

It only takes a couple of seconds per calf to administer the dose, but it’s important for the calf’s head to be in the proper tilted position. 

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