"Needle-free" vaccine delivery on horizon

Saskatoon, Sask., September 25, 2001

New intranasal and skin vaccine delivery options, such as vaccine patches and nasal sprays, are promising to revolutionize the way vaccines are delivered to livestock, say researchers at the Veterinary Infectious Disease Organization (VIDO) in Saskatoon, Sask. These needle-free vaccine delivery systems will reduce meat damage, improve vaccine effectiveness and make disease treatment easier for producers.

“The most obvious benefit is it will address meat damage caused by needle vaccinations – the number one challenge of the meat industry’s quality control,” says Dr. Maria Baca-Estrada, a Senior Scientist with VIDO.

From a science perspective, intranasal and skin delivery could improve vaccine effectiveness, she says. “The new delivery routes target the nasal passage, the intestinal tract and the skin, complementing the natural defences built up in those areas.”

Baca-Estrada, her team, and other VIDO scientists are working on a variety of needle-free delivery systems and the vaccines that could be delivered with them. “We believe needle-free systems of vaccine delivery are the way of the future. And though we are breaking new ground with this research, we have advanced this technology in a short period of time and are learning more every day about how the body interacts with the environment and disease-causing organisms.”

Studies have proven that placing a vaccine patch on the skin surface stimulates immune responses similar to needle injection, she says. “You might imagine that with a patch, very few vaccine molecules would pass through to the animal, but in fact, they do and the uptake is tremendously efficient.”

Larger animals such as cattle, pose a greater challenge because they have thick skin. But hair follicles are permeable and they possess immune system cells that prevent air-borne bacteria from entering the body, says Baca-Estrada. “So we want to find ways to take advantage of that.”

Patches for larger animals may need tiny micro-needles to break the skin enough for the vaccine to enter, she explains. Or a roller with tiny needles may be needed to apply vaccine directly to the skin. “The vaccine needs to be delivered to the live epidermis, just beneath the top layer of dead skin.”

Finding the right delivery method is also crucial for intranasal vaccine delivery says Baca-Estrada. “Again, this route capitalizes on providing protection at the site where most pathogens enter the body. Secondly, it moves vaccination away from muscle injection.”

Currently, a new intranasal gun for delivering vaccine into the nasal passage is being tested at VIDO. “After getting poor results using a delivery system designed for humans, we contacted the University of Saskatchewan engineering department to develop a prototype specifically for livestock.”

Another possibility for swine, for example, may be to expose them to mist while they’re watering, she says. A high-pressure air gun for “shooting” vaccines into the skin is also being tested at VIDO by Baca-Estrada’s colleagues.

“More work is needed to perfect this technology before it can get to producers. But this early work is extremely promising,” she says.

The research effort in animals is complementary to work on needle-free vaccine delivery being conducted in human medicine at other research centres, she says. In fact, the work at VIDO may have some human application possibilities. “Many people would welcome alternatives to the reactions and pain of needle vaccinations.”

VIDO is global leader in vaccine research for the control of infectious diseases in food animals and poultry and is a wholly-owned University of Saskatchewan not-for-profit institute. It operates with substantial support from the Government of Alberta and the Government of Saskatchewan. This research is funded by British Columbia Investment Agriculture Foundation, Agriculture and Food Council of Alberta, Canadian Adaptation and Rural Development in Saskatchewan (CARDS) Program, Manitoba Rural Adaptation Council, Agricultural Adaptation Council – Ontario, Saskatchewan Horned Cattle Trust Fund, Saskatchewan Marketing Deductions Fund, Kamloops Stockmen’s Association and Manitoba Cattle Producers.

For more information, contact:

Stuart Bond
Associate Director, Producer Relations
Veterinary Infectious Disease Organization
Phone: (306) 966-7474
Fax: (306) 966-7478