Bold claim: a new nasal vaccine could change the way we fight whooping cough. A live, intranasal candidate called BPZE1 has shown promising results in reducing or preventing colonisation by Bordetella pertussis, the bacterium behind whooping cough. These findings come from a randomized, placebo-controlled phase 2b trial conducted at University Hospital Southampton and the University of Oxford, aiming to evaluate safety and efficacy in healthy adults aged 18–50.
BPZE1 lowers colonisation by pertussis
The study enrolled 53 participants who were fully vaccinated against COVID-19 and did not have recent pertussis vaccination or infection. Participants were randomly assigned to receive a single intranasal dose of BPZE1 at 10^9 CFU or a placebo, with a 60–120 day gap before a controlled challenge using virulent B. pertussis. Researchers collected nasal washes and blood samples to monitor bacterial presence and immune responses.
In the modified intention-to-treat group, 58% of BPZE1 recipients showed no detectable colonisation on days 9, 11, and 14 after the challenge, compared with 33% in the placebo group. Among those who received a sufficiently high challenge dose, 60% of BPZE1 recipients were free of detectable B. pertussis versus 25% in the placebo group — a statistically significant difference.
Safety profile and tolerability
BPZE1 was generally well tolerated. Most participants reported only mild adverse events, such as nasal irritation or headaches, and there were no serious adverse events or trial discontinuations. The rate of unsolicited adverse events was similar between the vaccine and placebo groups.
Why this matters for infection prevention
The intranasal BPZE1 vaccine’s apparent ability to block colonisation suggests it could reduce transmission of whooping cough, addressing a gap left by current vaccines. Given its safety profile and the encouraging efficacy signals, BPZE1 is a strong candidate for progression into larger phase 3 trials.
Implications for clinicians and public health professionals
If these results are replicated in broader populations, BPZE1 could become a valuable tool for pertussis prevention, protecting individuals and communities by limiting spread of the disease. It also highlights the potential of mucosal vaccines to complement existing strategies.
Reference
Gbesemete D. et al. Efficacy, immunogenicity, and safety of the live attenuated nasal pertussis vaccine BPZE1 in the UK: a randomised, placebo-controlled, phase 2b trial using a controlled human infection model with virulent Bordetella pertussis. Lancet Microbe. 2025; DOI: 10.1016/j.lanmic.2025.101211.
Author note
This article is available under the Creative Commons Attribution-Non Commercial 4.0 License.
Would you like this rewritten piece tailored for a specific audience (clinicians, policymakers, or a general reader) or adjusted to a particular length or style?
