Laboratory results with mice indicate that exposure to pathogens after treatment of their nares with an antigen free nanoemulsion offers protection against pathogen challenge and can induce protective pathogenic immunity.

We have demonstrated that an antigen-free nanoemulsion applied to the nares of mice kills an inhaled organism and also acts as a mucosal adjuvant by presenting the pathogen to the immune system.  In contrast, the presentation of other forms of inactivated pathogens to mucosal surfaces does not yield an effective immune response, suggesting that the nanoemulsion-killed organisms are uniquely immunogenic.

Using nanoemulsions as a prophylaxis has a particular set of advantages. The first is that an immune response occurs specifically when needed in the period after exposure, an important factor, as it is at this time that ongoing pathogen exposure might lead to infection despite the initial killing of the organism by the nanoemulsion.  It supplements vaccine programs as it provides the individual with specific immunity to the exact organisms exposed to regardless of genetic or antigenic changes.  The need for attenuated infection with its possibility to incapacitate is avoided. 

In a murine influenza challenge study, 80% of the animals pretreated with saline alone died from influenza pneumonia.  Seventy percent of the antigen free nanoemulsion protected animals survived the challenge (Fig 1).

Potential High Value Unique OTC Product:

The concept of an antigen free safe OTC preventive for influenza has significant potential as a prophylaxis for influenza that would be used to prevent flu infection when there is a high risk of exposure.  High risk events could include air travel, visits to the pediatrician’s office, hospital or any situation where groups of people congregate.  Other examples include trips to a crowded shopping mall, visits to the pediatrician's office, the gym or a sports event.  The product would be applied by the consumer as a nasal spray prior to the time of anticipated exposure.  

Status / Development Plan:

Formulation development is complete.  Much of the product safety, toxicity and stability work is underway and integrated with the active NanoBio influenza vaccine program.  Experience with other nanoemulsions indicates that manufacturing scale-up will be a straight forward process.  

Installation of a product development and commercialization arrangement with an appropriate pharmacutical partner represents the next step in the development program for this product.

Fig. 1:  Murine Antigen-free Influenza Prevention Experiment

Study Design:

• Active arm animals protected with nanoemulsion nebulized into their nares
• Control arm animals pretreated with nasal saline
• 90 minutes later, a 80X lethal dose was nebulized into chamber
• Mice were followed for evidence of influenza pneumonitis
• Repeated on four different groups of animals

Results:

• Eighty percent of animals pretreated with saline alone died from influenza pneumonia (red line).
• Seventy percent of the antigen free emulsion protected animals survived the lethal challenge.

Conclusions: 

• Pretreatment of nares of mice with an antigen free nanoemulsion prevented influenza pneumonitis after aerosolized lethal dose virus challenge
• Effect was present at two hours
• No toxicity from emulsion was observed (10-50 fold therapeutic index)

Publications

Donovan B, Reuter J, Cao Z, Myc A, Johnson K, Baker JR Jr (1999) Prevention of murine influenza A virus pneumonitis by surfactant nanoemulsions.

Antiviral Chemistry & Chemotherapy 11:41-49. Download PDF file of this article (2600K)