Protect calf health with an effective vaccination protocol

Vaccines are an investment in your herd’s future health, and complement a sound colostrum and nutritional program, and proper cleaning protocols. The most effective calf vaccination protocols have three elements, preventing disease and improving calf health, a convenient time and place to administer vaccinations, and a designated location to keep records. The best way to ensure you are following the most effective vaccine protocol is to follow the instructions on the vaccine product label and advice of your herd veterinarian.

How vaccines work

To fight infections, white blood cells in the immune system need to learn to make antibodies to help target bacteria or viruses. Vaccines imitate an infection in advance of an exposure, training the calf’s white blood cells to be ready to respond to a real infection. This training can take 14 to 21 days. The difference between a natural infection and a vaccine is the bacteria or viruses in the vaccine lack the virulence (disease-causing) factors and the ability to multiply in the calf’s body. After vaccination, special white blood cells and other immune factors remember the infection, which enables the body to respond more quickly the next time it encounters it. This memory is why calves that have been vaccinated or had a certain disease are usually more resistant to becoming sick with the same disease later on.

If an unvaccinated calf encounters disease-causing bacteria or a virus for the first time, taking two or three weeks to launch a full immune response can really set the calf back. By the time the calf’s immune system is ready to fight the infection, it may be widespread, reducing the calf’s ability to overcome the disease. The sooner a calf can overcome a disease, the sooner it can get back to growing into a productive and healthy herd member.

A calf exposed to disease just before or after vaccination can still become sick since it takes several days to produce a full immune response. Overwhelming exposure to bacteria and viruses can still overcome even a good vaccine. For this reason, limiting exposure to pathogens by using good hygiene and biosecurity is still important even when an effective vaccination program is in place.

Protect calf health

For some diseases, another approach to protecting calf health involves vaccinating a cow or heifer during pregnancy. This allows the cow or heifer to develop a response to a disease and pass their immunity (maternal antibodies) to their calf via colostrum. Vaccinating calves to supplement their immunity may still be necessary since protection is hard to predict. The level of protection a calf receives from colostrum directly relates to the amount of antibody in the colostrum, the amount of colostrum fed, the colostrum’s quality, and the ability of the calf’s gut to take in the antibodies. Research has shown calves do not absorb antibodies in colostrum well if it also has a high bacteria count. Calves fed colostrum sourced from cows from another farm or fed commercial colostrum replacers may not gain immunity to all the pathogens on your farm. Timing of the maternal vaccination is also critical, and the whole herd vaccination strategy must taken into account.

Maternal antibodies in a calf’s system can sometimes interfere with the development of the calf’s immune response to a vaccine. Higher levels of antibodies absorbed from colostrum will protect the calf longer, but also block a traditional vaccine for a longer time. Due to this reason, vaccines must be administered to calves at a specific age. Vaccine product labels specifically recommend ages for administering vaccines. Calves will require a booster vaccine if it is given at an age younger than recommended by the manufacturer. One exception is an intranasal vaccine, which specifically targets only the local immune system of the calf’s upper respiratory tract or nasal mucosa, so it is not blocked by maternal antibodies and can be given to calves at an early age. The best way to ensure you are following the most effective vaccine protocol is to follow the instructions on the vaccine product label and advice of your herd veterinarian.

Careful handling is key

Handling and storing vaccines correctly is essential for maintaining their effectiveness. If you feel your vaccination program isn’t adequately protecting your calves, improper vaccine storage and handling could be the problem. Every vaccine has specific handling instructions on the package or package insert. These guidelines must be followed to ensure the vaccines will work. Keeping vaccines at the right temperature all the time is crucial. Some require refrigeration and some do not. When buying vaccines, make sure you’re able to transport them properly; leaving a live vaccine in a hot car for a few hours or allowing it to freeze in the barn may inactivate it. Vaccines exposed to light—as might occur if they are stored in a barn window or on an open shelf in an alley—can also be damaged.

Storing vaccines in a fridge isn’t always the best answer either. One study found 76 per cent of barn refrigerators tested were unacceptable for storing animal health products due to incorrect temperatures and temperature fluctuations. Think about the fridge in your barn—a minimum and maximum recording thermometer can help you assess your refrigerator’s performance and protect your animal health product investments.

When vaccinating a group of calves, be mindful of where you are setting the vaccine down, the environmental temperature, and how long after mixing up a live vaccine it will remain effective. Oklahoma State University has useful instructions for making a Chute Side Vaccine Cooler, which can be found at

Vaccine protocol

Work with your herd veterinarian to examine the health and treatment, mortality, and culling records on your farm. This data can be used to determine which intestinal and respiratory pathogens that the calf health vaccination program should target, and how best to incorporate the vaccinations into the overall herd health strategy.

A small percentage of calves may not respond to vaccination, so ensuring booster vaccinations are given on time is crucial. This number of non-responders can also increase during stressful situations, so it is best to avoid vaccinating animals in conjunction with a stressful event, such as disbudding or dehorning, weaning, when mixing groups of calves, or when calves are experiencing heat stress, for example.

There are a variety of vaccines available to protect against common calf illnesses, such as pneumonia and various scours. Work with your herd veterinarian to develop a vaccination program as part of regular herd health and management to help calves stay healthy while they grow. It may be worthwhile to incorporate a vaccine protocol and later reassess calf health and growth to see if the vaccine has improved growth or reduced treatment costs. After all, vaccinations are an important part of good calf management.