ArkeaBio—a startup developing a vaccine to cut livestock methane emissions—has announced the first close of a Series A+ round at $7 million and brought in Frank Wooten, cofounder of virtual fencing company Vence, to take the helm as CEO.
Wooten takes over from Dr. Colin South, who is moving into the role of chief business officer at Massachusetts-based ArkeaBio. The move follows the recent appointment of high-profile biotech exec Dr. Zach Serber (cofounder of Zymergen) as CTO.
The funding round, co-led by Breakthrough Energy Ventures and AgriZeroNZ with support from other existing funders, will help ArkeaBio advance from animal studies to full field trials in 2026-2027, said AgriZeroNZ CEO Wayne McNee.
“A vaccine to reduce methane in ruminant animals has the potential to be a low cost, high-impact solution for a range of farming systems. ArkeaBio is a leader in the race to develop a viable methane vaccine.”
‘An elegant solution’
Multiple strategies are being explored to address methane emissions from belching livestock from cattle breeding programs and feed additives to editing the genes of the microbes in the rumen.
But the most cost-effective way to tackle the problem at scale within a reasonable timeframe is a vaccine, claims ArkeaBio, which raised a $26.5 million Series A round in 2024 led by Breakthrough Energy Ventures.
Wooten told AgFunderNews: “What I’ve learned along my journey in agriculture so far is that it’s really hard to change practices for folks, and vaccines are already used in 100% of livestock markets worldwide.”
While feed additives are likely to be an important part of the toolbox to tackle livestock emissions, he said, “The majority of animals outside of the US are actually not ever put on feed, so when we look at a solution for a broader global market, the ability of a vaccine to have impact not only at an animal level, but in the workflows of our customer base, is the most elegant way to get that uptick in adoption.”
He added: “Both Zach and I are here 100% because we view this as probably the most potentially scalable and impactful solution to methane mitigation and potentially climate change that exists.”
Mode of action and efficacy
So how does ArkeaBio’s proposed vaccine work, and how efficacious is it?
A potent greenhouse gas, methane is generated on farms both from manure and burping ruminants in a stomach compartment called the rumen. Here, microbes break down complex carbs to produce carbon dioxide and hydrogen, which are then converted into methane by another set of microbes (methanogens) and belched out.
According to Zerber, the vaccine prompts a cow’s immune system to produce antibodies that interfere with the second set of microbes: methanogens.
“The antibodies that the cow produces are in the saliva, and they end up in the rumen, where the methanogens thrive. The antibodies are exquisitely targeted just to the methanogens that we have used to train the immune system with the vaccine, and they bind to those methanogens. They don’t seemingly outright kill the methanogens, they simply impair their fitness so that they get out-competed by other microbes.
He added: “Methanogens only make up about 3% of the total microbial biomass in rumen. We’re simply trying to knock down that 3% and allow other microbes in the rumen to come take their place.”
Following administration of the vaccine, hydrogen that the methanogens would normally convert into methane is now taken up by other microbes to make other compounds such as volatile fatty acids, he explained.
“VFAs can be used as caloric inputs for the animal and are ultimately turned into milk or meat. It’s through this mechanism that we expect to also have an impact on productivity.”
Productivity gains?
Typically about 10% of the energy consumed by a cow is lost as methane, he noted, “So instead of losing that energy as methane, you could turn it into additional energy for the animal and improve the economics for the farmer.”
The amount of the productivity gain will be determined by how many of the methanogens the antibodies can tackle, he acknowledged, noting that there are more than 130 types of methanogens in the cattle rumen and ArkeaBio cannot yet disable them all.
“We are targeting the most abundant methanogens, first and foremost, and then turning our attention to the next most abundant and so forth. We’ve been able to knock down methane production by at times a double-digit percentage, at other times by single digit percentages. And we are doing more field trials in 2026 to continually improve that number and the longevity of action [a vaccine isn’t much use if you have to administer it too frequently].”
Minimum viable product
According to Wooten, “a minimum viable product for a methane reduction product, we believe, is in the 10 to 15% range, although that’s really a stepping stone as with Zach’s work we are continually stacking solutions on top of each other to improve that number. By the time a product with a 10-15% reduction is in market, we will probably be field testing other solutions at 20-25%
“But when you look at the productivity gains side of the equation, once you’ve knocked down 25% [of methane emissions] there’s 2.5 extra points of energy in that animal.”
A vaccine’s commercial viability also depends on the frequency with which farms would have to administer it, he said. “Ideally you’ve got a vaccine that lasts six or 12 months. But we certainly think there’s minimum viability in dairy for an intervention every three months. But it’s a solvable problem.”
While a 10-15% reduction may not sound like much (feed additive Bovaer promises a 30% reduction in lactating dairy cattle, while some seaweed companies claim reductions of up to 90%), this is just the beginning, said Zerber. He also noted that the effects of a vaccine are sustained, where feed additives must be administered continuously.
“Largely what I was brought in to do was build a reliable screening platform so we can take our capabilities around antigen discovery and operationalize them. This means taking candidates selected through a combination of bioinformatics and AI generative insights and then evaluate them empirically in a cost effective and fast manner to arrive at a set of antigens that are contributing to methane abatement.
“We are going to continue to run this capability and the product of it will be increased efficacy and increased longevity of action. And then you can add to that the more conventional ways people optimize vaccines such as adjuvant selection and routes of administration.”
Regulatory pathway and timetable
The regulatory pathway for vaccines for methane reduction is a little opaque as they are not targeting a pathogen or disease for example, so might be treated more like a feed additive than an animal drug from a regulatory perspective in some markets, said Wooten.
“One of our investors is AgriZeroNZ [which is part-owned by the New Zealand gov’t] so we are working hand in hand with them and the New Zealand government, as it relates to the regulations. Obviously, safety first is the number one principle, but we should be able to follow a similar pathway [to new feed additives for livestock methane reduction].”
Who will pay for livestock methane reduction?
But who will pay for methane-reduction solutions, whether it’s a vaccine or a feed supplement?
According to Wooten: “This is the key question for all climate solutions. I believe that the carbon markets will continue to get more robust over time, and we will spend as much time as possible to have our solution in those markets and share whatever is monetized with our customers.
“But for me, productivity is our North Star. If you’re able to produce more meat or dairy [from the same amount of feed] that is an attractive solution. That leads to adoption.”
For a highly productive dairy farm in New Zealand with revenues of up to NZ$4,000 ($2,343) per animal, he said, even a 1% boost in productivity means an extra NZ$40 ($23). “If you were to target a 3+ % productivity gain, you’d be surprised at what the global adoption rate would look like.”
He also noted that some parties such as Mars, Nestlé and Fonterra will pay a premium for goods from farmers that implement more sustainable practices as part of corporate commitments to reduce methane emissions or Scope 3 emissions more generally.
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