Vaxdyn, a Spanish biotech developing vaccines against drug-resistant bacteria, raised €11 million ($12.8 million) in Series A funding on September 7, 2026 to push its K-VAX candidate into Phase 1 clinical trials. The round, led by Biovance Capital with backing from Arcano Partners and the EIC Fund, will finance the Seville-based company's first human study of a vaccine targeting two of the World Health Organization's most urgent bacterial threats.
The funding comes at a moment when antimicrobial resistance has climbed the global health agenda, though progress in new treatments has been frustratingly slow. Vaxdyn's approach hinges on engineered whole-cell vaccines, a platform technology that displays conserved outer-membrane antigens from Gram-negative pathogens while stripping away the toxic components that typically make such bacteria dangerous in their natural form. It's a technical gamble, but one that could address pathogens for which traditional vaccine development has largely stalled.
K-VAX targets carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii, both classified as critical threats in the WHO's most recent bacterial priority pathogen list. These organisms cause a substantial portion of hospital-acquired infections resistant to last-resort antibiotics. Vaxdyn's proprietary LPS-null technology removes bacterial endotoxin (lipopolysaccharide) while preserving the immune-triggering proteins on the bacterial surface, a delicate balance that the company believes can generate protective immunity without inflammatory side effects.
Biovance Capital invested €4 million and anchored the round. Arcano Partners contributed €3.6 million through its public-backed Impacto Andalucía Innovación y Desarrollo fund, according to reporting by El Español. The EIC Fund, the equity investment arm of the European Innovation Council, also participated but has not disclosed the size of its commitment.
The company's broader ambitions extend beyond K-VAX. Its KAPAVAX program, which has received support from CARB-X since 2019, aims to develop a trivalent vaccine covering Acinetobacter, Klebsiella, and Pseudomonas aeruginosa. That trio accounts for a disproportionate share of infections that resist nearly all available treatments. According to WHO data from October 2024, better deployment of vaccines could cut global antibiotic consumption by 2.5 billion defined daily doses each year, though the timeline and feasibility of such reductions remain subjects of debate among public health researchers.
Vaxdyn spun out of the Instituto de Biomedicina de Sevilla in March 2011, founded by Michael McConnell, Pilar Pérez-Romero, and Jerónimo Pachón. CEO Juan José Infante co-invented the underlying vaccine technology. The company has accumulated support from a mix of public and philanthropic sources over the years. CARB-X, a U.S.-backed accelerator for antibacterial innovation, awarded Vaxdyn up to $892,000 in initial funding with option payments that could reach $6.36 million, according to the organization's portfolio disclosures. In September 2024, the European Innovation Council granted the company a €14.5 million EIC Accelerator award, structured as a combination of grant funding and potential equity. Earlier backing came from Fundación Botín's Mind the Gap program and several private investors.
The company operates from Dos Hermanas, just outside Seville, with an estimated staff of between two and ten employees according to LinkedIn. Research collaborations include Spain's National Center of Microbiology, LEITAT in Barcelona, and pharmaceutical manufacturer Reig Jofre, which Vaxdyn has named as a clinical supply partner.
Antimicrobial resistance killed 1.27 million people directly in 2019, according to a Lancet analysis that public health agencies continue to reference. That figure rises to 4.95 million deaths when counting cases where drug-resistant infections played a contributing role. Acinetobacter baumannii sits on the WHO's critical-priority tier; carbapenem-resistant Klebsiella pneumoniae strains occupy a similar classification within the Enterobacterales family.
The vaccine development landscape for these pathogens remains sparse. WHO data lists Vaxdyn among four known developers working on Klebsiella vaccines at various stages, alongside GVGH, Ominose, and Inventprise. The BEAM Alliance pipeline indicates K-VAX has reached IND/CTA-ready status, meaning the company has prepared investigational new drug or clinical trial authorization filings for regulators, though no submission date has been announced.
"We are delighted to support Vaxdyn as it advances K-VAX, a potentially life-saving vaccine, towards the clinic," Ricardo Perdigão Henriques, managing partner at Biovance Capital, said in a statement released with the funding announcement.
Infante characterized the raise as "a critical step in Vaxdyn's evolution into a clinical-stage company." The company has not disclosed when it expects to dose its first patient. A European Commission project under the CORDIS registry, also named K-VAX, lists an end date of December 31, 2026, with periodic reporting active as of several months ago.
Whether Vaxdyn's whole-cell approach can succeed where other vaccine strategies have struggled remains an open question. The science is promising, but translating bacterial immunology into protective vaccines has proven difficult before. Still, with limited alternatives on the horizon and the resistance crisis intensifying, investors appear willing to bet on unconventional platforms.
