Osivax reaches key milestone in phase 2a trial for broad-spectrum flu vaccine

Ella Day | June 6, 2025 | News story | Research and Development |  Ghent University Hospital, Osivax, Vaccine, Virology, clinical trial, influenza a 

Osivax has announced the completion of patient visits in its phase 2a trial evaluating a booster dose of OVX836, a broad-spectrum influenza A vaccine candidate. The final results from the trial are expected in the second half of 2025.

Conducted at the centre for vaccinology (CEVAC), Ghent University Hospital, Belgium, the trial investigated the safety and immune response of OVX836 in 117 healthy adults aged 20–64. Participants had previously taken part in earlier Osivax trials up to five years ago. The study evaluated two dosage levels of the vaccine and included both booster and primary vaccination groups.

“Reaching Last Patient Last Visit in this booster trial is a significant milestone,” said Isabel Leroux-Roels, principal investigator at CEVAC. “The study allows us to explore long-term responses to this novel vaccine, which could inform future flu prevention strategies.”

Nicola Groth, chief medical officer at Osivax, commented: “This is the first time we are examining immune persistence and boostability several years post-vaccination. These insights will be essential in our goal to develop a truly broad-spectrum flu vaccine.”

OVX836 targets the conserved nucleoprotein of the influenza A virus, offering potential protection across strains. The candidate has shown promising safety and efficacy in prior trials and is a leading asset in Osivax’s ambition to develop a pan-respiratory virus vaccine.

Ella Day

6/6/25