A VACCINE against Sars has moved a step closer with encouraging results from animal studies.

American scientists report in The Lancet today that a prototype vaccine produced a strong immune response in macaque monkeys.

A team from the University of Pittsburgh School of Medicine modified an adenovirus — the type of virus responsible for the common cold — by genetic engineering so that parts of it were like the coronavirus responsible for Sars. They injected it into six monkeys, following up with a booster shot 28 days later.

The vaccinated animals produced both an antibody and killer cell response to Sars.

The team has yet to show that the vaccine protects against infection, but says it holds promise of doing so. There will have to be more animal tests and safety trials in humans before it could be used.

Sars, a pneumonia-like disease, infected more than 8,000 people and killed 774 early this year. Some virologists fear that it may re-emerge this winter.

Another team, in Canada, is also searching for a vaccine. Professor Brett Finlay, of the University of British Columbia, has tested a vaccine in mice and rabbits, and plans to test three more in ferrets before moving on to monkeys.

It usually takes eight to ten years to develop a vaccine, but Professor Finlay said: “We have to move fast, so we’re planning human safety trials within a year. If Sars rears its ugly head before then, we’ll bypass ferrets and go straight into primates.”

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