ArkeaBio—a Boston-based startup developing a vaccine to cut livestock methane emissions—has raised a $15 million Series A2 round led by AgriZeroNZ and supported by Breakthrough Energy.
The firm has also reduced its headcount by about a third as it edges closer to commercialization, CEO Frank Wooten told AgFunderNews.
“Given the environment, we had to pare back some of our initiatives and really hone in on our initial market [New Zealand], initial product and critically initial revenues. As such, we needed to let go of some really great scientists as well as commercial folks to ensure runway to hit those critical milestones.”
He added: “This round is likely to take us through the first commercial product.”
‘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, said Wooten, who cofounded virtual fencing company Vence and joined ArkeaBio in September 2025.
“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.”
Mode of action and efficacy
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 called methanogens and belched out.
ArkeaBio’s vaccine prompts a cow’s immune system to produce antibodies that interfere with methanogens. As a result, hydrogen that the methanogens would normally convert into methane is taken up by other microbes to make compounds such as volatile fatty acids that could help cows produce more milk and meat.
It’s through this mechanism that ArkeaBio also expects to have an impact on productivity, although this is not something it would make claims about in its first product, stressed Wooten.
“We’ve seen early evidence of increases in the microbial communities in the cattle rumen that produce volatile fatty acids but we don’t anticipate any measurable effect on productivity until the methane reduction number is above 30%. And for our first product we’re looking at something closer to 10-15% reduction in methane.”
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, he noted.
“There are hundreds of methanogens, but there’s one particular one that represents nearly 50% of the methanogens in the rumen, so we’ve started by targeting that species. We’re also targeting the second largest species. This is just the beginning.”
Minimum viable product
A vaccine’s commercial viability also depends on the frequency with which farms would have to administer it, acknowledged Wooten, with the longer its methane-busting effects last, the better.
“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. So our initial product will be three months but we expect to go to six months by our second product. For beef cattle we believe that number needs to be closer to 12 months.”
He added: “The other thing we are aggressively looking at is the coformulation of vaccines, where you hit an animal with one vaccine that targets a number of things, so we are actively looking at a couple of very common dairy vaccines that are utilized by 99% of dairy cattle in New Zealand, for example.
“We would look to co-formulate our vaccine with those vaccines. Then the cost burden of the additional methane inhibiting vaccine drops. And our ability to offset that cost, whether it’s with a carbon credit, a premium [on the milk paid by the processor or end consumer], or productivity gains, suddenly becomes much more attainable. And as such, we think it becomes a much more attractive product.”
What’s next?
ArkeaBio has spent the last two years working hand in hand with New Zealand government regulators to understand the regulatory pathway and timeline and expects to submit an application next year, said Wooten.
The hope is that the product could then be commercialized and start generating revenues in 2028, he said.
