The article discusses the role of bacterial outer membrane (OM) vesicles in host-pathogen interactions. OM vesicles are small, spherical structures released by Gram-negative bacteria that serve as vehicles for the secretion of proteins and lipids. These vesicles play a crucial role in establishing colonization, transmitting virulence factors, and modulating host defense responses. They can carry toxins, adhesins, and other virulence factors, which they deliver directly into host cells or tissues. The formation of OM vesicles is influenced by environmental factors and bacterial genetics, and they can be produced by both pathogenic and nonpathogenic bacteria. OM vesicles are particularly important in the dissemination of virulence factors, such as toxins, and in modulating the host immune response. They can also facilitate interbacterial interactions, such as toxin transport and genetic exchange, and contribute to the establishment and longevity of bacterial infections. The article highlights the complex mechanisms by which OM vesicles interact with host cells and the potential for engineered vaccine strains to utilize these vesicles for antigen delivery.The article discusses the role of bacterial outer membrane (OM) vesicles in host-pathogen interactions. OM vesicles are small, spherical structures released by Gram-negative bacteria that serve as vehicles for the secretion of proteins and lipids. These vesicles play a crucial role in establishing colonization, transmitting virulence factors, and modulating host defense responses. They can carry toxins, adhesins, and other virulence factors, which they deliver directly into host cells or tissues. The formation of OM vesicles is influenced by environmental factors and bacterial genetics, and they can be produced by both pathogenic and nonpathogenic bacteria. OM vesicles are particularly important in the dissemination of virulence factors, such as toxins, and in modulating the host immune response. They can also facilitate interbacterial interactions, such as toxin transport and genetic exchange, and contribute to the establishment and longevity of bacterial infections. The article highlights the complex mechanisms by which OM vesicles interact with host cells and the potential for engineered vaccine strains to utilize these vesicles for antigen delivery.