
The outcome of a trial published in Science Translational Medicine, shows encouraging results for a new vaccine targeting group B meningococcus (MenB), a significant cause of meningococcal disease worldwide, and establishes proof-of-concept in humans that a gene-based vaccine platform can induce protective antibody responses against bacteria.
The investigational vaccine, ChAdOx1 MenB.1, developed by researchers at the University of Oxford, was shown to be safe and to elicit a significant immune response in healthy adults aged 18 to 50 in this Phase I/IIa trial.
Capsular group B meningococcus (MenB) remains the most common cause of invasive meningococcal disease in individuals under the age of 25 in high-income regions. Of the 12 types of Neisseria meningitidis, it is one of the six (A, B, C, W, X and Y) that cause most cases of invasive meningococcal disease, particularly in infant, toddler, and young adult populations.
This new vaccine uses ChAdOx1, the Oxford adenoviral vector platform which was proven effective in the Oxford-AstraZeneca COVID-19 vaccine trial, to express a protein from the MenB bacterial membrane.
Participants were given one- or two-doses and some participants also received a licensed MenB vaccine as a priming dose. The results demonstrate that two doses of ChAdOx1 MenB.1 elicited protective serum bactericidal antibody responses in 100% of recipients against a particular MenB strain which is targeted by the vaccine.
No safety concerns were identified throughout the trial. The results also suggest that a multivalent approach would be necessary to achieve broader protection against different MenB strains.
“Our findings support the safety and immunogenicity of ChAdOx1 MenB.1 and demonstrate the potential of adenoviral-vectored platforms for bacterial vaccines,” said Professor Sir Andrew Pollard, Director of the Oxford Vaccine Group and one of the lead investigators of the study.
“While the current formulation offers strong protection against specific strains, our next step will be to broaden the vaccine’s coverage and enhance its efficacy against different strains of the bacteria.”
“These encouraging Phase I/IIa results highlight the progress we are making in the fight against bacterial diseases. The ChAdOx1 vector has again demonstrated its versatility, inducing a robust immune response to this challenging antigen targets. This study provides a strong foundation for the development of other vaccines against bacterial diseases,” says Professor Christine Rollier.
The research underscores Oxford’s ongoing commitment to advancing innovative vaccine technologies to meet pressing global health challenges.
More information:
Christina Dold et al, A phase 1/2a clinical trial to assess safety and immunogenicity of an adenoviral-vectored capsular group B meningococcal vaccine, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adn1441
Citation:
New B meningococcus vaccine shows promise in early-stage trial (2025, May 16)
retrieved 16 May 2025
from https://medicalxpress.com/news/2025-05-meningococcus-vaccine-early-stage-trial.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

The outcome of a trial published in Science Translational Medicine, shows encouraging results for a new vaccine targeting group B meningococcus (MenB), a significant cause of meningococcal disease worldwide, and establishes proof-of-concept in humans that a gene-based vaccine platform can induce protective antibody responses against bacteria.
The investigational vaccine, ChAdOx1 MenB.1, developed by researchers at the University of Oxford, was shown to be safe and to elicit a significant immune response in healthy adults aged 18 to 50 in this Phase I/IIa trial.
Capsular group B meningococcus (MenB) remains the most common cause of invasive meningococcal disease in individuals under the age of 25 in high-income regions. Of the 12 types of Neisseria meningitidis, it is one of the six (A, B, C, W, X and Y) that cause most cases of invasive meningococcal disease, particularly in infant, toddler, and young adult populations.
This new vaccine uses ChAdOx1, the Oxford adenoviral vector platform which was proven effective in the Oxford-AstraZeneca COVID-19 vaccine trial, to express a protein from the MenB bacterial membrane.
Participants were given one- or two-doses and some participants also received a licensed MenB vaccine as a priming dose. The results demonstrate that two doses of ChAdOx1 MenB.1 elicited protective serum bactericidal antibody responses in 100% of recipients against a particular MenB strain which is targeted by the vaccine.
No safety concerns were identified throughout the trial. The results also suggest that a multivalent approach would be necessary to achieve broader protection against different MenB strains.
“Our findings support the safety and immunogenicity of ChAdOx1 MenB.1 and demonstrate the potential of adenoviral-vectored platforms for bacterial vaccines,” said Professor Sir Andrew Pollard, Director of the Oxford Vaccine Group and one of the lead investigators of the study.
“While the current formulation offers strong protection against specific strains, our next step will be to broaden the vaccine’s coverage and enhance its efficacy against different strains of the bacteria.”
“These encouraging Phase I/IIa results highlight the progress we are making in the fight against bacterial diseases. The ChAdOx1 vector has again demonstrated its versatility, inducing a robust immune response to this challenging antigen targets. This study provides a strong foundation for the development of other vaccines against bacterial diseases,” says Professor Christine Rollier.
The research underscores Oxford’s ongoing commitment to advancing innovative vaccine technologies to meet pressing global health challenges.
More information:
Christina Dold et al, A phase 1/2a clinical trial to assess safety and immunogenicity of an adenoviral-vectored capsular group B meningococcal vaccine, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adn1441
Citation:
New B meningococcus vaccine shows promise in early-stage trial (2025, May 16)
retrieved 16 May 2025
from https://medicalxpress.com/news/2025-05-meningococcus-vaccine-early-stage-trial.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.