New Pediatric Study Results Show Nasal Vaccine May Halt Whooping Cough Spread

A new pediatric study reveals that the intranasal whooping cough vaccine candidate, BPZE1, is safe and elicits a robust immune response. This novel vaccine aims to halt pertussis transmission by inducing immunity directly at the nasal entry point, a key limitation of current vaccines.

Marcus Cole

October 3, 2026 · 4 min read

ILiAD Biotechnologies announced today the publication of promising results from a pediatric clinical trial for its novel whooping cough vaccine, BPZE1. The findings, detailed in The Lancet Infectious Diseases, show the intranasal vaccine candidate was safe and produced a robust immune response in children and adolescents. This development marks a significant step toward addressing a critical weakness of current vaccines: their inability to prevent the transmission of the bacteria that causes the disease.

The Phase 2b study, named SUPER, evaluated the live attenuated vaccine in healthy participants aged 6 through 17. According to the company's announcement, the trial demonstrated that a single intranasal dose of BPZE1 stimulates strong immune defenses both systemically throughout the body and, crucially, in the nasal mucosa—the primary entry point for the Bordetella pertussis bacterium. This dual action is central to the vaccine's potential to not only protect individuals from illness but also to stop them from spreading it to others.

Key Findings: Safety and Robust Immune Response

The SUPER trial was a randomized, double-blind, placebo- and active-comparator-controlled study, a rigorous design considered a high standard in clinical research. Its primary goal was to assess the safety of BPZE1 and its ability to generate an immune response, also known as immunogenicity. ILiAD Biotechnologies reported that the study successfully met its main objective, showing a significant increase in pertussis-specific secretory IgA (S-IgA) in the nose. This antibody is a key component of mucosal immunity and is believed to be essential for preventing the initial infection and subsequent transmission.

In addition to inducing a strong mucosal defense, the vaccine candidate also demonstrated a favorable safety profile. The study also addressed a key practical question for future use: whether BPZE1 would interfere with other routine immunizations. The results showed no interference when the nasal vaccine was co-administered with a Tdap vaccination, which protects against tetanus and diphtheria. This finding suggests BPZE1 could potentially be integrated into existing vaccination schedules without diminishing protection against other serious diseases.

How BPZE1 Aims to Halt Pertussis Transmission

Current global efforts to control whooping cough, or pertussis, are hindered by a fundamental limitation of existing vaccines. While today's acellular pertussis vaccines are effective at preventing severe disease, they do not stop individuals from becoming colonized with the Bordetella pertussis bacteria and spreading it to others. This allows the infection to continue circulating, posing a risk to vulnerable populations. BPZE1 is designed specifically to overcome this challenge by inducing immunity directly at the site of infection.

The core difference lies in the vaccine's design and delivery. BPZE1 is a live attenuated vaccine, meaning it uses a weakened but still living version of the pertussis bacterium. Administered as a nasal spray, it is designed to mimic a natural infection to build a strong defensive barrier in the nose and throat. This approach contrasts sharply with current acellular vaccines, which primarily trigger a systemic, blood-based immune response.

The nasal mucosal immunity generated by BPZE1 acts as a first line of defense, intended to prevent the bacteria from taking hold, or colonizing, in the first place. By blocking colonization, the vaccine has the potential to break the chain of transmission. While the recent publication focused on the pediatric SUPER trial, a separate adult study of BPZE1 previously highlighted this unique potential. Robert Read, who led that study, noted it was "the first time a whooping cough vaccine has been shown to prevent the bacteria from colonising the nose and throat in humans."

Saul Faust, the coordinating investigator for the pediatric SUPER study and a professor at the University of Southampton, emphasized the importance of this new approach. "Despite widespread vaccination, pertussis continues to circulate globally," Faust stated. He explained that the "robust BPZE1-induced nasal mucosal immune responses, non-interference with a current acellular pertussis vaccine, and favorable safety profile observed in this study further support the continued development of BPZE1 as a novel intranasal vaccine with the potential to address the shortcomings of current pertussis prevention."

What's Next for BPZE1 and Pertussis Prevention

The successful completion and publication of this Phase 2b study represent a critical milestone for the BPZE1 program. The positive safety and immunogenicity data from this pediatric trial, which builds upon five previous clinical studies in adults, provide a strong foundation for the vaccine's continued development. However, it is important to note that the vaccine is still in the clinical trial phase and is not yet approved for public use.

The next step for the BPZE1 vaccine program is to advance to larger Phase 3 trials to confirm these findings in a larger population, which could lead to regulatory approval for wider use. For public health officials and families awaiting better protection against whooping cough, the key development to monitor is the initiation or announcement of Phase 3 clinical trials for BPZE1. These trials will be the final and most comprehensive stage of testing before the vaccine can be considered for widespread public use.