A SARS vaccine is unlikely to be available soon because few drug companies want to invest in a product that may have no demand without another major outbreak, said a Hong Kong researcher who has worked on a vaccine.

Of at least 16 possible SARS vaccines developed worldwide, only one has been picked up by a drug company, in China, where it’s in an early testing phase, said University of Hong Kong microbiologist Yuen Kwok-yung.

Drug companies are reluctant to invest in vaccines for severe acute respiratory syndrome because there might be scant demand if SARS doesn’t resurface, Yuen said on the sidelines of a news conference announcing a new infectious diseases laboratory.

“Once there is no commercial viability, it’s not going to happen even if you have a candidate vaccine in your laboratory,” said Yuen, who is on a team that has worked on one.

Academic researchers stop at the animal testing phase, Yuen said. Drug companies are needed to finance the necessary testing of new vaccines on humans, which requires costly insurance, he said.

SARS emerged in southern China’s Guangdong province in late 2002. It killed 349 people on China’s mainland and 774 worldwide before subsiding in June 2003.