Vaccine start-up from Flanders raises record EUR 30 million

For 12 years, virologists Johan Neyts and Kai Dallmeier have been working on their innovative vaccine technology at the Rega Institute in Leuven, Flanders. As such, they developed an optimized version of a preventive shot against yellow fever.
 
“Yellow fever vaccines have been produced on fertilized chicken eggs for 80 years,” Neyts explains. “However, many batches are rejected because this process is difficult to standardize. It’s also cumbersome. I witnessed, for example, how a producer in Senegal had to fly in fertilized chicken eggs from Germany every 2 weeks.”

Neyts and Dallmeier have developed a patented technology that no longer requires the use of fertilized chicken eggs. Neyts: “We managed to paste the genetic code of the live but attenuated yellow fever virus into a specially developed plasmid, or circular piece of DNA. That can be grown in large culture vessels. It’s a very standardized process that can be applied anywhere in the world. Following injection, the body starts to produce its own yellow fever vaccine based on the plasmid.”

The candidate vaccine has already proven to be very effective in laboratory animals. “Not only does it generate antibodies; it also triggers all arms of the immune system. However, as academics, we don’t have the resources to handle large-scale production and clinical trials ourselves.”

To raise the necessary capital, the recently founded Leuven spin-off AstriVax has been attracting investors for the past year and a half. The company – founded by CEO Hanne Callewaert, Johan Neyts, Kai Dallmeier and two KU Leuven colleagues – raised EUR 30 million, the largest amount of seed capital ever for a KU Leuven spin-off.

“We are convinced of the potential presented by this innovative vaccine technology as well as its broad application possibilities,” says Shelley Margetson, managing partner of V-Bio Ventures, which led the capital round together with Fund+. The other investors involved are Mérieux Equity Partners, BNP Paribas Fortis Private Equity and the KU Leuven Gemma Frisius Fund.

By early 2025, AstriVax plans to start clinical trials of the yellow fever vaccine. “There is a great demand for such vaccines in Africa, South America and from the growing international travel market,” says AstriVax CEO Hanne Callewaert.

“Besides generating long-lasting immunity, another advantage of our vaccine is that it does not require a cold chain transport,” adds Neyts. “This kind of transport involves keeping temperatures low constantly, even as low as -20 to -80 degrees Celsius, like with the recent mRNA COVID vaccines. Not needing such a demanding cold chain is a big advantage in tropical areas.”

Meanwhile, the X-factor of AstriVax’s “plug and play” platform is the fact that it’s modular. “We can cut into the code of the yellow fever vaccine, which means we can also introduce a piece of code from other viruses while using the yellow fever vaccine as a vector or carrier,” explains Neyts.

To continue building its future, AstriVax is moving into the BioHub in Haasrode (Flanders). This cutting-edge lab and office facility also houses Virovet, a leading biotech company that develops virus inhibitors and vaccines for animals.

The new CEO of AstriVax, Hanne Callewaert, earned her stripes at various pharma and biotech firm for over 15 years. She used to be the CEO of the Leuven biotech company Oxurion, which focuses on eye disorders. She also spent over 10 years in a variety of roles at the vaccine branch of UK pharmaceutical giant GlaxoSmithKline. “I always said I wanted to work on vaccines again one day,” she comments.

AstriVax is just one of the many start-ups, scale-ups and other companies that make Flanders’ business and research ecosystem for life sciences & health so successful. Want to unravel this ecosystem in a virtual yet interactive way? Head to the Flanders360 platform and discover 300+ successful companies, universities, R&D centers, incubators and other players active in Flanders’ life sciences & health industry. 

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