The World Health Organization says SARS had been "stopped dead in its tracks," but experts warn China holds the key to whether it resurfaces.

The UN agency lifted a month-old warning to avoid non-essential travel to Taiwan. The only warning still in effect at press time was for Beijing.

WHO officials say the spread of the disease is a byproduct of modern globalization - because it spread quickly through jet travel. But it was contained using centuries-old public health tactics, such as quarantine and surveillance of suspected victims.

Such methods would likely remain the most effective weapons against SARS, because there is no vaccine, and drugs have proven of limited use.

SARS has killed about 800 people and left more than 8,400 sick since first being detected in southern China in November. New cases spiked in March and April but have plunged in recent weeks.