# Tiny packages, big potential: bacterial membrane vesicles in vaccinology

## TL;DR

Bacterial membrane vesicles (BMVs) are being explored as safe and effective vaccine platforms due to their ability to modulate the immune system and deliver antigens.

## Contribution

The paper reviews recent advances in BMV engineering and bioprocessing for next-generation vaccine development.

## Key findings

- BMVs resemble eukaryotic extracellular vesicles and can be engineered for antigen display.
- Licensed OMV vaccines demonstrate their safety and immunogenicity.
- Innovations in bioprocessing improve BMV scalability and mucosal delivery.

## Abstract

Bacterial membrane vesicles (BMVs) are nanoscale, bilayered proteolipid structures secreted by both Gram-negative and Gram-positive bacteria. Initially considered cellular debris, BMVs are now recognized as evolutionarily conserved entities with critical roles in bacterial communication, immune modulation, virulence factor delivery, and horizontal gene transfer. Their structural and functional resemblance to eukaryotic extracellular vesicles has fueled growing interest in their use as versatile vaccine platforms. Licensed meningococcal OMV vaccines established proof-of-concept for their safety and immunogenicity, and ongoing studies are extending applications to enteric pathogens and viral infections. Recent advances in genetic engineering, glycoengineering, and modular antigen display systems have enabled the design of “plug-and-play” BMVs with reduced reactogenicity and enhanced protective efficacy. In parallel, innovations in bioprocessing and formulation technologies are improving scalability, stability, and delivery, including mucosal routes. This review highlights the immunological properties, translational potential, and key challenges of BMV-based vaccines, with an emphasis on strategies to optimize safety, antigen specificity, and manufacturing for next-generation vaccine development.