Areas of focus

I. Vaccines:
Post-weaning colibacillosis
Swine influenza
Porcine Respiratory and Reproductive Syndrome
Porcine circovirus

II. Formulation and Delivery:
Needle-free
Oral vaccination, mucosal immunization
Transcutaneous delivery
Viral and bacterial vectors

III. Innate immunity
Antimicrobial peptides
Novel immunomodulators (CpG, host defence peptides)

IV. Respiratory infections
Airway function, organic dust

V. Pig as model for human infections
Hepatitis C
Bordetella pertussis (whooping cough)
E. coli (traveller’s disease)
Influenza

VI. Technology Transfer
VIDO Swine Technical Group

Example 1: Post-weaning colibacillosis

Example 2: Vaccine formulation

Example 3: Needle-free delivery

Example 4: PRRS

Example 5: Respiratory infections

Example 6: Innate immunity

There are significant economic losses to global swine production due to post-weaning colibacillosis caused by E. coli bearing enterotoxigenic F4 fimbriae (ETEC). Fimbriae are appendages that allow the bacteria to attach themselves to other cells.

Prevention of disease depends on the creation of immune responses in the small intestine. Vaccines that could be delivered to this surface, called mucosal vaccines, are currently not available and treatment is limited to the use of antibiotics.

We are developing mucosal vaccines by using a "gut-loop" model in three-week-old piglets. Separate loops are surgically created in the jejunum of piglets, and vaccines are administered into each loop. Three weeks later, immune responses are studied by analyzing each loop.

This model allows analysis of immune responses at the intestinal surface in a living animal - the same environment that the vaccine must be effective in. Various vaccine formulations can be studied in only one animal.

The gut loop model allows researchers to visualize
the immune response at the intestinal surface for
different volumes of vaccine. This figure shows results
from different loops following immunization with varying doses of the F4 protein. Strength of the immune response
according to levels of IgG and IgA antibody-secreting-cells
was greatest for the 500 ug dosage.

A goal of modern vaccine research is the development of needle-free vaccine delivery strategies. VIDO is testing a variety of delivery systems for intradermal or transcutaneous application in livestock.

Immune responses at the mucosal surfaces are distinct from the immune responses that occur in the body as a whole. Delivery of vaccines to the mucosal surfaces (i.e. oral, intranasal) represents a potential strategy for creation of both mucosal and systemic (throughout the body) immunity. VIDO is investigating the mechanisms of mucosal immunity and vaccine formulations that can be delivered to the mucosal surfaces.

Intranasal device developed at VIDO and the University of Saskatchewan

Antimicrobial peptides (AMPs), also called host defence peptides, are small molecules found in virtually all life forms.

AMPs were originally called "nature's antibiotics" because of their potent antimicrobial activity. Research has demonstrated that these molecules are potent innate, or natural, immune system components with both antimicrobial and immuno-stimulatory function.

VIDO is investigating the use of AMPs against disease-causing organisms in pigs and the role of AMPs in respiratory infections. In particular, we are interested in the effects of stress, bacterial infections, and animal movement on the expression of AMPs. AMPs will also be used as vaccine adjuvants to create a broad and balanced immune response.

This figure shows the amount of the bacteria E. coli present after treatment with the antimicrobial peptide PG. After one hour of incubation with PG, all of the bacteria have been killed.

This figure shows the amount of the bacteria E. coli present after treatment with different volumes of the antimicrobial peptide PR-39. After six hours of incubation with PR-39, all of the bacteria have been killed.