Adjuvant Vaccine Development

We have developed a new form of antimicrobial nanoemulsion composed of soybean oil, emulsifying agents, and ethanol. The emulsion has 200 nM particles that inactivate enveloped viruses by fusing with the virus and disrupting its membrane. When this material was mixed with influenza virus and placed into the nares of animals, it produced rapid and intense immune responses that protected animals from subsequent virus challenge. This immunity was achieved with only a single application of virus and nanoemulsion and involved both mucosal and cytotoxic components. (Myc A, Kukowska-Latallo JF, Bielinska AU, Cao P, Myc PP, Janczak K, Sturm T, Grabinski MS, Young K, Chang J, Hamouda T, Olszewski MA and Baker JR, Jr: Development of immune response that protects mice from viral pneumonitis after a single intranasal immunization with influenza A virus and nanoemulsion. Vaccine 21(25-26); 2003, 3801-3814).

Graph of intranasal vaccination of animals with various virus/nanoemulsion mixtures in mice — Intranasal vaccination of animals with a virus/nanoemulsion mixture induced high levels of anti-influenza A, Ann Arbor strain. IgG. Mice were vaccinated one time with nanoemulsion alone, formaldehyde-killed virus, formaldehyde-killed virus/nanoemulsion, or virus/nanoemulsion mixture. Sera were collected on day 20 of the experiment for the assessment of IgG. Antibodies levels were expressed as an index of the geometric mean +/- SD for each experimental group. P-value was calculated using Student's t-test with C-Cochran and Cox correction. Symbol (*) depicts significance (P<0.05) between animals vaccinated with formaldehyde-killed virus/nanoemulsion versus animals vaccinated with virus/nanoemulsion.

Mice immunized intranasally with the virus/nanoemulsion mixture did not show signs of illness, and their core body temperatures were within normal range for 14 days. Moreover, the lungs of immunized animals appeared grossly normal, and histological examination showed no indication of influenza pneumonitis or upper airway inflammation. These results show that nanoemulsions can inactivate virus without causing upper or lower airway mucosal toxicity in treated animals.

As current approaches to vaccination for a number of viral agents have drawbacks due to the use of live virus, complex vaccination protocols or the addition of adjuvants unacceptable for humans, we are currently determining whether mixing nanoemulsion with specific viral agents will provide a rapid and effective means for a killed virus vaccine for these specific viral agents. We presently focus on Smallpox, B. anthracis and Hepatitis B adjuvant vaccine development.