The Behavioral Intention and Influencing Factors of Medical Staff toward COVID-19 Vaccinations.

This study mainly explored the behavioral intention and influencing factors of medical staff toward COVID-19 vaccinations. Medical staff were taken as the research subjects. This study selected 300 research subjects by the intentional sampling method and conducted a questionnaire survey.

Development of a respiratory syncytial virus vaccine using human hepatitis B core-based virus-like particles to induce mucosal immunity.

Background: Respiratory syncytial virus (RSV) is an important viral pathogen responsible for severe infection of the lower respiratory tract in children under the age of 5 years. No vaccines against RSV are currently in clinical use. Vaccine-associated enhanced respiratory disease (ERD) caused by excess Th2 type responses was observed in a clinical trial of formalin-inactivated RSV (FI-RSV) in antigen-naïve infants.

Recombinant Bacillus subtilis spores expressing MPT64 evaluated as a vaccine against tuberculosis in the murine model.

Recombinant Bacillus subtilis spores expressing a TB antigen, MPT64, were tested for their ability to protect mice against tuberculosis challenge. A chimeric gene consisting of the spore coat gene cotB fused to mpt64 was constructed, and expression of a stable CotB-MPT64 hybrid protein of the spore coat verified. Spores were evaluated as a live vaccine and also formaldehyde inactivated.

Mucosal vaccination against tuberculosis using inert bioparticles.

Needle-free, mucosal immunization is a highly desirable strategy for vaccination against many pathogens, especially those entering through the respiratory mucosa, such as Mycobacterium tuberculosis. Unfortunately, mucosal vaccination against tuberculosis (TB) is impeded by a lack of suitable adjuvants and/or delivery platforms that could induce a protective immune response in humans. Here, we report on a novel biotechnological approach for mucosal vaccination against TB that overcomes some of the current limitations.

Killed Bacillus subtilis spores as a mucosal adjuvant for an H5N1 vaccine.

Heat killed spores of the Gram-positive bacterium Bacillus subtilis have been evaluated as a vaccine delivery system with mucosal adjuvant properties for influenza. Killed spores were able to bind H5N1 virions (NIBRG-14; clade 1) and, when intra-nasally administered to mice, resulting immune responses, both humoral and cell mediated, were enhanced compared to immunization with the virion alone. Levels of both systemic IgG and mucosal sIgA specific to the virion were elevated.

Immunization with Bacillus spores expressing toxin A peptide repeats protects against infection with Clostridium difficile strains producing toxins A and B.

Clostridium difficile is a leading cause of nosocomial infection in the developed world. Two toxins, A and B, produced by most strains of C. difficile are implicated as virulence factors, yet only recently has the requirement of these for infection been investigated by genetic manipulation.

Oral delivery of a DNA vaccine against tuberculosis using operator-repressor titration in a Salmonella enterica vector.

Attenuated Salmonella enterica offers a vaccine delivery route that has the benefits of enhanced immunogenicity and oral delivery. The majority of immunization studies have been conducted to deliver recombinant proteins, expressed from a gene that is either chromosomally integrated or carried on a low- or medium-copy number plasmid. There are, however, an increasing number of reports demonstrating the delivery of DNA vaccines, but the high-copy number plasmids that are preferentially used for this application are unstable in Salmonella.

Mucosal delivery of antigens using adsorption to bacterial spores.

The development of new-generation vaccines has followed a number of strategic avenues including the use of live recombinant bacteria. Of these, the use of genetically engineered bacterial spores has been shown to offer promise as both a mucosal as well as a heat-stable vaccine delivery system. Spores of the genus Bacillus are currently in widespread use as probiotics enabling a case to be made for their safety.

Cytoplasmic delivery of antigens, by Bacillus subtilis enhances Th1 responses.

Endospores of the Gram-positive bacterium, Bacillus subtilis, have been used successfully for delivery of antigens where the immunogen is expressed on the spore surface. In this work the spore has been engineered to deliver antigens to the cytoplasm of macrophages by expressing listeriolysin O (LLO) or a derivative, LLO(L461T), that is stable at neutral pH, from the B. subtilis vegetative cell.

Immunostimulatory activity of Bacillus spores.

Bacillus species, typically Bacillus subtilis, are being used as probiotics and mounting evidence indicates that Bacillus species are important for development of a robust gut-associated lymphoid system (GALT). We used a number of gut isolates of Bacillus incorporating three species, B. subtilis, Bacillus licheniformis and Bacillus flexus to evaluate the nature of interaction between spores and the GALT.