Formulation Attributes Impact Immune Profile of an Oral and Thermostable COVID-19 Subunit Vaccine.

While approved vaccines for COVID-19 provide protection against severe disease and death, they have limited efficacy in the prevention of infection and virus transmission. Mucosal immunity is preferred over systemic immunity to provide protection at the point of entry against pathogens such as SARS-CoV-2. VaxForm has developed an oral vaccine delivery platform that elicits mucosal and systemic immune responses by targeting immune cells in the gut through C-type lectin receptors.

Group A Streptococcus Vaccine Targeting the Erythrogenic Toxins SpeA and SpeB Is Safe and Immunogenic in Rabbits and Does Not Induce Antibodies Associated with Autoimmunity.

Group A streptococcus (GAS) is a global pathogen associated with significant morbidity and mortality for which there is currently no licensed vaccine. Vaccine development has been slow, mostly due to safety concerns regarding streptococcal antigens associated with autoimmunity and related complications. For a GAS vaccine to be safe, it must be ensured that the antigens used in the vaccine do not elicit an antibody response that can cross-react with host tissues.

A rational, systematic approach for the development of vaccine formulations.

With the continuous emergence of new infectious diseases and new strains of current diseases, such as the novel H1N1 influenza in 2009, in combination with expanding competition in the vaccine marketplace, the pressure to develop vaccine formulations right the first time is increasing. As vaccines are complex, costly, and have high risk associated with their development, it is necessary to maximize the potential for development of a successful formulation quickly. To accomplish this goal, the historical empirical approach to formulation development needs to be updated with a rational, systematic approach allowing for more rapid development of safe, efficacious, and stable vaccine formulations.

An alternative approach to combination vaccines: intradermal administration of isolated components for control of anthrax, botulism, plague and staphylococcal toxic shock.

Background: Combination vaccines reduce the total number of injections required for each component administered separately and generally provide the same level of disease protection. Yet, physical, chemical, and biological interactions between vaccine components are often detrimental to vaccine safety or efficacy.

Methods: As a possible alternative to combination vaccines, we used specially designed microneedles to inject rhesus macaques with four separate recombinant protein vaccines for anthrax, botulism, plague and staphylococcal toxic shock next to each other just below the surface of the skin, thus avoiding potentially incompatible vaccine mixtures.

Synthetic Toll-like receptor 4 agonist enhances vaccine efficacy in an experimental model of toxic shock syndrome.

The development of new protein subunit vaccines has stimulated the search for improved adjuvants to replace traditional aluminum-containing products. We investigated the adjuvant effects of a synthetic Toll-like receptor 4 (TLR4) agonist on vaccine efficacy in an experimental model of toxic shock syndrome. The TLR4 agonist E6020 has a simplified structure consisting of a hexa-acylated acyclic backbone.

Relationship of adsorption mechanism of antigens by aluminum-containing adjuvants to in vitro elution in interstitial fluid.

The objective of this research was to determine how the mechanism by which antigens adsorb to aluminum-containing adjuvants affects the elution upon exposure to interstitial fluid. Antigens (alpha lactalbumin, bovine serum albumin, lysozyme and myoglobin) that adsorb to aluminum-containing adjuvants principally by electrostatic attraction were found to elute readily in vitro when exposed to interstitial fluid. Phosphorylated antigens (alpha casein, hepatitis B surface antigen and phosphorylated bovine serum albumin) that adsorb to aluminum-containing adjuvants principally by ligand exchange exhibit little if any elution during 12-24 h in vitro exposure to interstitial fluid.

Role of aluminum-containing adjuvants in antigen internalization by dendritic cells in vitro.

An important step in the induction of an immune response to vaccines is the internalization of antigens by antigen presenting cells, such as dendritic cells (DCs). Many current vaccines are formulated with antigens adsorbed to an aluminum-containing adjuvant. Following injection of the vaccine the antigens may either elute or stay adsorbed to the adjuvant surface.

Effect of phosphorylation of ovalbumin on adsorption by aluminum-containing adjuvants and elution upon exposure to interstitial fluid.

The phosphate content of commercial ovalbumin was increased from 1.8 to 3.2 mol PO(4)/mol ovalbumin by conjugation of phosphoserine and reduced to 1.

Distribution of adsorbed antigen in mono-valent and combination vaccines.

The distribution of alpha-casein, bovine serum albumin (BSA), myoglobin and recombinant protective antigen (rPA) in mono-valent and combination vaccines containing aluminum hydroxide adjuvant was studied by fluorescence microscopy and flow cytometry. Green and red fluorescent probes were conjugated to the antigens. Adsorption isotherms of the fluorescently labeled proteins to aluminum hydroxide adjuvant demonstrated that incorporation of the fluorescent probe did not significantly affect the adsorption.

Effect of thermal treatment during the preparation of aluminum hydroxide adjuvant on the protein adsorption capacity during aging.

Six aluminum hydroxide adjuvants, poorly crystalline aluminum oxyhydroxide (AlOOH) were prepared using different thermal treatments of amorphous aluminum hydroxide (Al(OH)3) in an effort to increase the protein adsorption capacity. All of the adjuvants initially exhibited a higher protein adsorption capacity. However, the protein adsorption capacity decreased during aging at room temperature.