In an era where the rapid evolution of pathogens pose constant threats to livestock health, mRNA vaccines offer a potential solution that builds on conventional vaccinology, providing faster development times and greater flexibility in protecting animals from emerging diseases.

At the 2024 Beef Improvement Federation (BIF) Symposium in Knoxville, Tenn., in July, Jon Beever’s talk, “Biotechnology 101 – A practical, producer guide to gene editing, vaccinology, and genomics,” explored the potential of mRNA vaccines, which could bring a new era in cattle health within five to seven years.

“mRNA vaccines are really not all that different from how we do things now,” Beever explains. “The mechanism is different, but the idea is the same. We are still giving the immune system an opportunity to respond to bacterial and viral antigens that it may get exposed to.”

Conventional vaccines used in cattle production, such as modified live and killed vaccines, are not foreign concepts to most producers. 

Modified live vaccines use weakened live organisms to stimulate long-lasting immune responses in cattle, often only requiring a single dose. In contrast, killed vaccines use inactivated pathogens that cannot replicate, meaning multiple doses are needed to achieve effective immunity. 

“With mRNA vaccines, instead of putting in the protein or entire pathogen like we would with a normal vaccine, we’re actually cutting to the chase,” Beever says. “We’re putting in this mRNA molecule, letting our cells use that mRNA molecule to produce the protein of interest, and then they can display it and the cells can respond to it.”

Adaptability

Just because the new technology is a little different does not mean it is dangerous, Beever says. Presently, traditional vaccines are cost-effective to produce, but as the technology further develops, he says there are many of upsides to mRNA vaccines the industry could benefit from. 

Conventional vaccines cannot be developed and adapted quickly for new pathogens or strains, whereas with mRNA we have the potential to quickly develop a vaccine that will elicit a robust and protective immune response, Beever says.

Vaccines during the COVID-19 pandemic are an example of how mRNA technology allows for quick development. 

“Every few months, a new version of COVID-19 appeared, and we were told new boosters were being made to keep up,” Beever adds. “But traditional vaccines like the flu shot, are based on last year’s virus strains, so if a new one pops up we would not be protected.”

If the virus’ genetic code is known, scientists can create a new mRNA vaccine to match it. This rapid adaptability allows vaccinations to stay ahead of evolving pathogens. 

“mRNA technology also allows us to develop vaccines for pathogens that we’ve not historically been successful at producing with traditional vaccines,” Beever explains. “Human trials have demonstrated this potential, leading to the successful development of an Ebola vaccine and others.”   

Targeted response

The diverse applications of mRNA technology extend beyond its adaptability. Beever highlights the flexibility in vaccine design, which allows for targeted immune responses.

“There’s a potential to design vaccines where we can give the immune system the appropriate antigen to develop the best immune response,” he says.
This customization could be particularly beneficial in addressing regional disease variations.

“The opportunity for regional vaccines to where a specific bovine respiratory disease (BRD) complex, for instance, was impacting a set of herds in a certain region, you could have a specific vaccine for that,” Beever adds.

Rapid response to pathogens that traditional vaccines don’t offer full protection against is another significant benefit mRNA brings to the table, he says. This improved protection could enhance herd health management and better safeguard cattle against various diseases we currently struggle with today, he adds.

Currently, there is only one mRNA vaccine approved for livestock use. This on-demand prescription vaccine targets several different viruses. Beever does not foresee mRNA vaccines making their way onto cattle ranches in the “near future” but he says once the technology is further developed, they could be even cheaper than conventional vaccines.

“Many producers I’ve spoken to have been open-minded and curious about the potential of these mRNA vaccines,” Beever says. 

He encourages ranchers to have the desire to learn what’s next for the industry and to embrace change. A healthy dose of skepticism paired with a curious attitude can go a long way in the advancement of the industry.

“From a molecular biology standpoint, we can now look at the variety of antibodies that are generated from a vaccination and see the strength of the immune response,” Beever says. “We can then go in and develop these vaccines that might generate a better immune response in every animal, regardless of genetic makeup.”

He says this scientific advancement is important, especially given the growing interest in finding alternatives to antibiotics in livestock management.

“With the current pressure for the industry to reduce antibiotic use, we have got to do everything we can to have our animals immunized with the best chance of responding to anything they should encounter,” he continues. “That will require some refinement of the vaccines that we currently use, and mRNA might be one of those technologies that provides that.”

Herd health today

While the future of vaccinology is exciting, Beever emphasizes there are many practical ways producers can improve their programs today. 
Enhancing herd health starts with a well-managed vaccination system overseen by a veterinarian or extension agent to ensure a well-thought-out management scheme.

This collaboration ensures the most effective vaccines are used and administered properly, reducing the risk of disease outbreaks and improving overall herd health.

“Take a second look at your current vaccination plan,” Beever suggests. “Even if the return on investment isn’t immediately obvious, it’s crucial to maximize your investment. This means using vaccines correctly and at the right time to ensure the health and productivity of your herd.”
By focusing on proper vaccination practices now, Beever hopes producers can set the stage for integrating advanced technologies like mRNA vaccines in the future. 

Embracing these innovations will not only enhance the health and productivity of cattle but also contribute to the sustainability and resilience of the livestock industry. 

Editor’s note: Elizabeth Rosson is a freelance writer from Louisa, Va.