MEXICO CITY: The first case of swine flu was confirmed in Asia yesterday as health experts said a vaccine should be ready in a matter of months and Mexico said the virus was not as aggressive as originally feared.

Confirmation by the authorities in Hong Kong that a traveler from Mexico tested positive for the H1N1 influenza A virus saw an entire hotel quarantined and sent shivers through the territory which was at the center of the 2003 SARS crisis.

Denmark also joined the list of affected countries while more cases emerged of victims contracting the virus even though they had not traveled to Mexico.

The Mexican government raised its confirmed toll to 15 dead and 328 people infected as the country began a five-day shutdown to halt the virus’ spread.

Health Minister Jose Angel Cordova said the new count — up from 12 dead and 300 infected — did not represent new cases coming in but rather testing and analysis of a backlog of “probable” cases in the epicenter of the crisis.

“Fortunately the virus is not so aggressive — it’s not a case of avian flu, which had a mortality rate of nearly 70 percent,” Cordova told reporters.

He said the H1N1 flu virus, while far more contagious than avian flu, was easily treated with antiviral medicine “if treatment is given from the first day.”

The World Health Organization has said that an official pandemic is now imminent, raising its alert level to five out of six on Wednesday.

However, a senior official at the UN agency said that a vaccine was in the pipelines. “We have no doubt that making a successful vaccine is possible in a relatively short period of time,” Marie-Paule Kieny, WHO director of the Initiative for Vaccine Research said, adding it may take four to six months.

Mexican authorities meanwhile canceled the traditional gatherings of workers to celebrate May Day, as the country went into a five-day holiday they hoped would minimize public contact and slow the viral spread.

Restaurants, tourist sites and other public venues remained closed in the capital and elsewhere. “Stay at home with your family,” President Felipe Calderon said in an address to the nation, which is officially on holiday until Tuesday.

All the confirmed deaths from the virus have occurred in Mexico except one, a Mexican toddler who died across the border in the United States.

US health officials say they have confirmed 141 infections in 19 states, while a total of 14 countries have now confirmed cases.

Hong Kong Chief Executive Donald Tsang said the 25-year-old Mexican man who had tested positive had arrived in the Chinese territory on Thursday from Mexico via Shanghai. “I will raise the alert level from serious to emergency,” Tsang added.

Among the latest cases revealed in Germany was that of a nurse who had treated a patient with the virus, but had not been to Mexico. The nurse subsequently recovered.

Scottish authorities also confirmed the first case of swine flu in Britain involving someone who had not recently traveled to Mexico. The new patient was a close friend of newly-weds Iain and Dawn Askham, who became Britain’s first confirmed cases earlier this week after returning from honeymoon in Mexico.