SARS vaccine undergoing animal testing
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* Rosanna Tamburri

Canadian researchers have developed 2 potential SARS vaccines now undergoing animal testing.

Both prototypes have produced antibody responses in animals, a first step toward the eventual development of a human vaccine, said Dr. Lorne Babiuk, director of the University of Saskatchewan's Vaccine and Infectious Disease Organization (VIDO). But it isn't known yet whether the antibodies will effectively block the replication of the SARS virus, Babiuk said.

One of the prototypes is a conventional killed-virus vaccine developed by researchers at the BC Centre for Disease Control, the University of BC and VIDO.

The second vaccine was developed by researchers at McMaster University using an adenovirus vector, a common-cold virus that has been engineered with DNA from the SARS virus. The vaccines were tested on mice and ferrets at the Southern Research Institute in Alabama, a Level 3 laboratory.

“Both showed early signs of being able to provide protection” in animals, said Jack Gauldie, director of the Centre for Gene Therapeutics at McMaster. While the vaccine candidates have generated immunity, some aspects of the immunity may be damaging, he cautioned. Further tests on other animal models are likely, he said.

A human SARS vaccine could be available in about 2 years, depending on the final test results and whether “the disease rears its ugly head again,” Babiuk added. Another outbreak would likely spur researchers to fast-track the process, he said.

Several other SARS vaccine candidates are currently under development in Canada, but all are in earlier test phases, Gauldie said. Canadian researchers began work on a vaccine just over a year ago, after an outbreak of the potentially deadly respiratory disease. Developing a market-ready vaccine usually takes about 10 years, but researchers are hoping to reduce the time substantially in the case of SARS. — *Rosanna Tamburri*, Oakville, Ont.