The Nose Knows – Intranasal Cattle Vaccines
Intranasal vaccines for cattle can initiate a rapid immune response with less interference from maternal antibodies.
Intranasal vaccines don’t just differ from injectable vaccines in the route of administration. The nasal route of administration actually spurs a different immune response in cattle. This makes intranasal vaccines a good match for young calves or in on-arrival programs.
Intranasal vaccines are a key tool for producers battling respiratory illness in cattle, which has remained one of the top challenges to cattle health for decades. The USDA Animal and Plant Health Inspection Service (APHIS) notes respiratory problems accounted for 24% of pre-weaned heifer deaths in its 2014 Dairy National Animal Health Monitoring System (NAHMS) survey.
Neonatal calves have immature immune systems, which predisposes them to disease, said Scott Nordstrom, DVM, associate director of ruminant life cycle management at Merck Animal Health.
“The other challenge with vaccination of neonatal calves is that they have received colostrum,” he said. “The colostrum has maternal antibodies that help protect calves, but they can also neutralize antigens from an injectable vaccine, which is referred to as maternal antibody interference. We want to work with the colostrums – not against them.”
Components of immunity
There are three basic components of immunity in the calf:
- Maternal antibodies from colostrum provide passive immunity for disease protection. This is essential to protect a newborn for at least the first two to four months of life. As time passes, these maternal antibodies dissipate.
- Innate immunity is the built-in response to disease challenges that nearly all healthy animals are born with.
- Active immunity is protection from disease developed after exposure to disease or through vaccinations.
There is a window of susceptibility to disease that occurs when maternal antibodies are waning. Peer-reviewed research suggests that maternal antibodies can inhibit the immune response to a vaccine in calves until their decline by 6 months of age.
“One of the reasons we love intranasal vaccines is that they are demonstrated to be effective in the face of maternal antibodies because the antigen is introduced in close proximity to the mucosal surfaces,” Nordstrom said. “They stimulate nonspecific immunity at the mucosal surfaces that helps provide protection against the respiratory pathogens found in the vaccine.”
For dairy, administering intranasal vaccines to the young calf and then following up with a booster dose at approximately 6 weeks of age is the gold standard for young calf care. Branding is often the first opportunity to vaccinate beef calves, and intranasal vaccines work for this age.
Stress is a disease trigger
In beef cattle, summer pneumonia and respiratory illness after weaning and shipping are important disease challenges.
Cortisol – a hormone that is naturally released during periods of stress – suppresses the immune system, Nordstrom says.
“High cortisol levels also weaken white blood cells, which makes it harder for them to kill viruses and bacteria,” he explained. “The vaccination program should help prepare calves for the stress well before the stress occurs.”
Intranasals can help provide effective protection against both viral and bacterial respiratory diseases. In the case of infectious bovine rhinotracheitis (IBR), the disease may already be within the animal waiting for its opportunity.
“IBR is a herpes-virus, like the chickenpox virus in humans,” Nordstrom said. “That virus becomes latent in your body, and – under periods of stress – it can resurge and become shingles. IBR is in the same class of viruses. When cattle are under stress, the virus can become active, and cattle may start to shed it again.”
Other common viruses like the bovine respiratory syncytial virus (BRSV) are less likely to be latent within the animal’s body but are widespread and reoccur often. BRSV is considered one of the main pathogens responsible for bovine respiratory disease (BRD), which persists after decades of advancements in both vaccinations and treatments.
Injection management
With needle-free administration, intranasal vaccinations meet best management practices outlined in the industry’s Beef Quality Assurance (BQA) program. With vaccinations, no single program fits all. Veterinarians can help producers stay current on vaccination practices and help create a vaccination program that best fits their operation.
Key Points:
- Passive immunity is derived from colostrum containing maternal antibodies during a calf’s first days of life.
- Passively derived maternal antibodies can interfere with and inhibit the immune response to an injectable vaccine in calves until the maternal antibodies decline around 6 months of age.
- One way to reduce the effects of maternal antibody interference is to use an intranasal vaccine.
Photo cutlines 1: istockphoto.com/seraficus
Photo cutline 2: istockphoto.com/Deb Drury
