Transdermal Vaccines

SmartVet’s transdermal vaccine development is aimed at expanding the use of its versatile remote delivery technologies into the field of vaccines and other animal pharmaceuticals. The focus of current research efforts are infectious diseases, particularly Foot and Mouth Disease (FMD) and vaccines routinely used by livestock producers for animal health maintenance.  SmartVet is leading the collaboration on this ambitious project in partnership with researchers at Kansas State University’s College of Veterinary Medicine and the Department of Biochemistry and Molecular Biophysics.

In cooperation with Professor John Tomich, Director of the KSU Biotechnology/ Proteomics Core Facility, SmartVet is pursuing research and development work utilizing Professor Tomich’s patented synthetic peptides known as Branched Amphiphilic Peptide Capsules (BAPC) for potential use in a range of vaccines and other animal pharmaceuticals. It has already been demonstrated that BAPCs interact strongly with plasmid double-stranded DNAs and 200-300 bp double-stranded RNAs. Our current research focuses on utilizing BAPC/nucleic acid complexes to deliver DNA vaccines in vertebrates and dsRNA as transcript knockdowns in targeted parasites.  Proof of concept work has already been completed which evidences that macrophage cell transfection occurs within 60 minutes following dermal application.

In cooperation with Professor John Tomich, Director of the KSU Biotechnology/ Proteomics Core Facility, SmartVet is pursuing research and development work utilizing Professor Tomich’s patented synthetic peptides known as Branched Amphiphilic Peptide Capsules (BAPC) for potential use in a range of vaccines and other animal pharmaceuticals. It has already been demonstrated that BAPCs interact strongly with plasmid double-stranded DNAs and 200-300 bp double-stranded RNAs. Our current research focuses on utilizing BAPC/nucleic acid complexes to deliver DNA vaccines in vertebrates and dsRNA as transcript knockdowns in targeted parasites.  Proof of concept work has already been completed which evidences that macrophage cell transfection occurs within 60 minutes following dermal application.

For more information about FMD and the VetGun delivery system click here

In 2001 FMD caused $10 billion of direct and indirect losses, and 6 million animal deaths in the UK. Scientific consensus is that it is not a matter of ‘if’ but rather ‘when’ this virus will be introduced into the US again. Australia is another country that has a high risk of FMD introduction. The VetGun system used in combination with a transdermal FMD vaccine could provide a more effective way to protect the $1 Trillion US agricultural industry from a virus that has been estimated could cause losses of anywhere between $50 billion and $100 billion, and the destruction of more than 60 million animals.   

There are seven known serotypes and more than 60 subtypes of the FMD virus, and there is no universal vaccine against the disease. The FMD virus survives in lymph nodes and bone marrow of host animals. Large amounts of the virus are found in all body secretions and excretions. Every time an infected animal breathes out it releases large amounts of infectious virus, exposing other animals. It is precisely for this reason that herding and yarding animals for vaccination by injection is undesirable.

FMD is non-zoonotic and is therefore easily transmitted by man, intentionally or mistakenly. It is for this reason that FMD is regarded by the US Dept. of Homeland Security (DHS) as the priority biosecurity/bioterrorism risk to the US livestock industry.

What problems does the VetGun delivery system solve in FMD control?

In the context of infectious diseases, if the animals still need to be gathered and confined for delivery, a transdermal vaccine has limited benefit over injectable vaccines. The VetGun system is the key to unlocking the true potential of topical vaccination, by making it possible to dose animals without any gathering or confinement. 

The incubation period of FMD can be up to 14 days, so animals may be infectious without showing any clinical signs. Therefore, the act of corralling the animals together a confined space for vaccination can itself be a major contributor to the spread of the disease. The VetGun has already proven its capability to deliver highly effective topical parasite treatments in the field, eliminating the need to gather and yard animals. With the VetGun, administration of treatment can be done by a single person from land based vehicles or even from the air, with no need for any close animal contact or handling facilities.

The VetGun delivery system therefore facilitates the deployment of rapid response containment strategies, reducing the time and number of people required to administer a vaccination program. In addition, wild animals can be a reservoir and major source of transmission of infectious diseases. The VetGun is the only delivery system that enables large numbers of wildlife to be vaccinated either by professional staff, or by ranchers themselves. 

In epidemiological terms, initiation of vaccination and rapidity of vaccine administration are critical success factors in the effective control of outbreaks. There are existing epidemiological models developed by the Center for Animal Disease Modeling and Surveillance, these are capable of quantifying the epidemiological benefits of a VetGun delivered topical FMD vaccine.

If this project is successful, the VetGun system could become the method of choice for combating the spread of infectious diseases such as FMD. 

(for more information about FMD threats and vaccines click here).

What unique contribution can VetCaps make to the efficacy of topical vaccines?

Over and above unlocking the true potential of topical vaccines by enabling them to be delivered in the field with a VetGun, a specially modified VetCap may also provide important clinical benefits. The main challenge facing topical vaccines has been penetrating the protective barrier of the skin, particularly the stratum corneum and underlying tight junctions. The skin comprises a ‘bricks and mortar’- like structure of keratinocytes in an intercellular matrix. The impact of a specially designed capsule can be made to cause a physical interruption of the skin structure. As a result of previous evidence gathered from histology and pharmacokinetic work, our hypothesis is that modified VetCaps may be able to temporarily change the physical state of the intercellular matrix. Our research indicates this may facilitate antigen penetration via the intercellular pathway to the deeper layers of the skin. These deeper layers are a highly immunocompetent zone which is uniformly accepted as an ideal target for antigen delivery. Using certain novel adjuvants in conjunction with the modified VetCaps could further enhance the potential to generate strong immune responses to the topically applied antigens. For more information about research on transdermal vaccine delivery you can click on the following links:

Advances in Lipid-Based Subunit Vaccine Formulations

Effective transcutaneous immunization by antigen-loaded flexible liposome in vivo

Transcutaneous Vaccines - Novel Advances in technology and delivery for overcoming barriers