COVID-style mRNA vaccines hold big promise for livestock, say scientists

mRNA could be a critical tool in the event of an outbreak of foot and mouth or lumpy skin disease but it also has enormous potential for a range of endemic diseases producers deal with daily, University of Queensland professor Tim Mahony said.

With LSD, mRNA could overcome one of the biggest hurdles associated with the current vaccine that would have devastating trade implications - that animals vaccinated can't be differentiated from animals infected.

FMD and LSD have slipped from the headlines but the devastation they would cause the beef, sheep and dairy business in Australia remains just as potent and arguably the risk of an incursion is even higher now, given the ongoing global spread.

COVID vaccination is also no longer the hot ticket news item it was but the advancements it has fuelled in mRNA can be drawn on by livestock industries.

The technology uses a copy of a molecule called messenger ribonucleic acid, or mRNA, to produce the components of a pathogen that can induce protective immune responses.

Currently, there are no mRNA vaccines approved for use in food-producing animals.

This point has just been made prominently in a research paper published in the journal Vaccines, from experts at the Queensland Alliance for Agriculture and Food Innovation's Centre for Animal Science.

Lead author, Prof Mahony said mRNA vaccine technology could play an important role in boosting livestock production to meet global food demands.

"Infectious diseases are limiting the production of edible protein for human consumption, which is affecting both the quality and quantity of the product," he said.

"One benefit of mRNA vaccines is the flexibility to make changes when new variants of diseases emerge, which makes it an ideal solution for reducing losses within livestock production systems in the future.

"For a complex disease like bovine respiratory disease, a conventional approach would require us to make a vaccine for every individual pathogen.

"But an mRNA vaccine allows us to pull apart those pathogens and select which ones to incorporate into a singular vaccine."

International research has shown that every percentage point reduction in beef cattle losses due to disease could provide enough food to meet the needs of 317 million people, while a 10 per cent reduction in disease could substantially reduce greenhouse gas emissions.

Work is still underway around the world to determine whether mRNA can be applied to FMD and LSD, including projects funded by Australian government and industry bodies.

"For FMD, it would be more straightforward but the vaccine would vary geographically, similar to what we saw in Coronavirus," Prof Mahony said.

The advantage would be the ability to quickly change the vaccine to suit the outbreak.

"In the event of an incursion, the first thing would be to work out where it likely came from because that would tell us what strain it is and what vaccine to apply," Prof Mahony said.

"With mRNA, we could then very quickly create the vaccine if it wasn't one that was already in stocks somewhere in the world that we could access.

"For LSD, which is a more complex virus, we think multiple antigens in an mRNA vaccine would be needed."

The advantage of mRNA in LSD would be that one of its key abilities is to identify animals with the live virus as opposed to those vaccinated.

It's that issue with the current vaccine that could create massive trade issues should the vaccine ever be used in Australia.

"Having the capacity to say an individual animal was vaccinated, not infected, helps both in controlling the outbreak and in discussions with trade partners," Prof Mahony said.

The researchers urge governments, peak industry bodies and veterinary health companies to make the investment required to develop mRNA vaccines for ruminants and other livestock.

"As we saw with the pandemic, if you put enough resources in the one spot, things can happen very quickly," Prof Mahony said.