The BPZE1 vaccine induces protection against B. pertussis, thereby preventing nasal colonization. However, the long-term protection and herd immunity effects induced by the existing BPZE1 vaccine are controversial. The objective of this study is to evaluate the safety and immunogenicity of BPZE1 vaccine when given intranasally.

This randomized, placebo-controlled, dose-escalation, phase 1b study included a total of 48 healthy participants (age 18-32 years). The participants were randomly assigned in a 3:1 ratio to three groups of increasing BPZE1 dose strength or placebo. The main endpoint of the study was adverse outcomes, both solicited and unsolicited, within 28 days of the treatment.

Within 28 days after starting the treatment, adverse events occurred in 1 (8%) participant in low-dose and placebo groups, and in 2 (17%) participants in the two groups of the higher dose. The most common treatment-related adverse events included oropharyngeal pain, cough (grade 2 or more), rhinorrhea, and nasal congestion. All the doses of BPZE1 were well tolerated with no solicited or unsolicited adverse events in either of the three groups.

The research concluded that the BPZE1 vaccine was safe and induced a high colonization rate in healthy adults. BPZE1 did not result in solicited or unsolicited adverse events and was immunogenic at all doses.