Tests on monkeys provide optimism on SARS vaccine

Doctors they are encouraged by early data from a prototype vaccine for SARS, saying it primed the immune defenses among a group of inoculated monkeys.

Six macaques who were injected with the vaccine and booster shot 28 days later yielded a strong response from both arms of their immune system -- antibodies and T-cells -- according to a study.

Two that were given a dummy vaccine showed no response.

The results are encouraging, even though the vaccine still has a long way to go, both in lab testing on animals and, if that works, on humans, before it can enter the public domain, its inventors say.

The test vaccine was created by Andrea Gambotto from the school of medicine at the University of Pittsburgh along with colleagues from the University of Pittsburgh and the US Centers for Disease Control and Prevention.

They genetically altered an adenovirus -- the virus that causes the common cold -- so that parts of it were similar to the so-called coronavirus which causes SARS.

The strength of the immune response varied according to the animal, but rose significantly after the booster was given. However, the vaccinated animals have still to be exposed to the SARS virus to see whether the formula works.

"These results show that a vaccine can induce strong SARS-specific immune responses in the monkey," Gambotto's team reports in Saturday's issue of the British medical weekly The Lancet.

"[They] hold promise for development of a protective vaccine against the SARS causal agent."

SARS believed to have surfaced in southern China late last year.