Mexico announced plans on Monday to revive its economy hit by a deadly swine flu epidemic it says has eased, but the global alert has triggered a trade dispute over bans on Mexican, U.S. and Canadian pork.

In a broadcast to the nation, President Felipe Calderon said the planned stimulus package would include a temporary reduction in taxes for cruise lines that visit Mexico, in a bid to lure back shiploads of foreign visitors.

The tourism sector, which accounts for 8 percent of Mexico's economy, has been badly hit by the epidemic of a new H1N1 flu virus strain, which prompted major operators like Carnival Cruise Lines to cancel visits.

"We are now going to concentrate on achieving the recovery of the economy as fast as possible," Calderon said, adding details of the stimulus plan would be given in coming days. "We're going to come out of this experience successfully and soon."

He repeated government assurances that Mexico, epicenter of the flu outbreak that has now infected more than 1,200 people in 21 countries, was over the worst of its own epidemic.

To date, 27 deaths have been confirmed -- 26 in Mexico and one in the United States. The flu's global spread has kept alive fears of a possible pandemic, although scientists say this strain does not appear more deadly than seasonal flu.

IMPACT ON TOURISM, AIRLINES

While the new H1N1 virus is not foodborne, fears of cross-border contagion stirred up international trade tensions after about 20 nations banned imports of pigs, pork and other meat from the United States, Canada and Mexico, the three most flu-affected countries.

Canada threatened to take China to the World Trade Organization unless Beijing backs down from its ban on imports of pigs and pork from the province of Alberta, where a herd of pigs was found to have the H1N1 strain.

Health experts, citing precedents such as the 1918 Spanish Flu pandemic that killed millions of people, warn the latest epidemic could attack more violently a few months from now.

In a brewing diplomatic dispute between Mexico and China over the treatment of Mexican citizens caught up in the flu alert, Mexico sent a plane to retrieve dozens of its nationals quarantined by Chinese authorities.

Mexico accused Beijing of discrimination against Mexicans, but China's Foreign Ministry rejected the criticism.

Calderon condemned the quarantine measures against Mexican citizens overseas as "discriminatory."

In Mexico, Health Minister Jose Angel Cordova said the government would lift the precautionary five-day shutdown it had imposed on public and business activities on May 1.

* "Influenza" refers to a family of viruses that include influenza A, influenza B and influenza C.

* Symptoms include sudden onset of fever, muscle aches, headaches, cough and sometimes diarrhea and vomiting. Flu feels far more severe than a cold.

* People can pass flu along before they feel ill and after they feel better. Flu viruses can be found not only in nasal secretions but in fecal matter.

* The "incubation period" for flu -- the time it takes from infection before symptoms develop -- is usually about 24 to 48 hours, although it is not clear what the case is for this new H1N1 swine flu virus.

* The virus can be transmitted on particles of saliva and mucus when people cough and sneeze close to one another. Experts generally agree that three feet (1 meter) is the distance these particles can travel between people.

* Flu viruses can also live for days or even weeks on dry surfaces. More and more evidence shows that people very frequently infect themselves by touching a contaminated surface, such as a computer keyboard, and then touching the nose, eyes or mouth.

* Flu viruses evolve, or mutate, constantly. New strains emerge regularly, which is why the annual flu vaccine must be reformulated every year.

* Flu viruses are believed all to originate in animals. Little changes or mutations in the DNA can allow them to more easily infect people. Some cause more serious symptoms than others.

* Flu viruses are frequently deadly. The World Health Organization estimates that flu kills 250,000 to 500,000 people in a normal year, more during pandemics, which last occurred in 1968, 1957 and 1918.

* Flu can kill directly by causing pneumonia, and it can also make people more vulnerable to bacterial infections that also kill.




Vaccines

U.S. vaccine supply could be limited in flu pandemic
By Lisa Richwine
Wed Apr 29, 2009 2:48pm EDT

Manufacturers have taken initial steps, but it would require months to make a vaccine to fight the new strain.

An immunization against a pandemic virus "will probably be the most highly sought-after product on the face of the earth," said Mike Osterholm, director of the Minnesota-based Center for Infectious Disease Research and Policy.

"In the face of a pandemic, it's hard to imagine any country willingly letting vaccine leave from within its border to another country just because there's a contract" with the U.S. government, he said.

The precarious situation was highlighted in 2004 when a British flu vaccine plant was contaminated, wiping out half the U.S. supply for that year.

The Bush administration in 2006 gave $1 billion to five companies to modernize production of vaccines and make them in the United States. The goal was to establish enough domestic capacity to supply vaccine within six months of the start of a pandemic to the entire U.S. population of about 300 million.

Building up U.S. production is still ongoing.

Sanofi-Aventis SA is the major supplier for the U.S. market, making about 50 million doses annually at a plant in Swiftwater, Pennsylvania.

A second Swiftwater plant could produce another 50 million doses of seasonal vaccine this year if cleared by U.S. regulators, Sanofi spokeswoman Donna Cary said. When fully operational, that plant could churn out 100 million doses of the three-strain seasonal vaccine, said Cary, but she declined to say when that would be.

Other companies including GlaxoSmithKline Plc and Novartis AG make at least part of the vaccine outside the U.S.

PHENOMENAL EXPANSION

The funding for vaccine manufacturing has produced "phenomenal expansion in manufacturing capacity," Dr. Anne Schuchat, an interim deputy director at the Centers for Disease Control and Prevention, told a Senate hearing.

Asked if the United States could produce 300 million doses domestically now, Schuchat said officials were "very optimistic," but added: "This virus can surprise us, and even with all those investments it may just technically be difficult."

Other experts agreed preparedness efforts had helped, particularly with Sanofi boosting its U.S.-based production.

"We are in a good position right now in the United States," said Dr. Kathleen Neuzil, who serves on the pandemic flu task force of the Infectious Diseases Society of America as well as a U.S. government advisory committee on vaccines.

Companies limit production each year based on how much officials think they can sell, and they could make more, she added.

Also, the seasonal vaccine contains three flu strains, but a pandemic vaccine might need only one. "You can make three times as much if only one strain is in the vaccine," Neuzil said.

Osterholm said it was too soon to predict the U.S. capacity, as it would depend in part on what dose would be needed and whether it could be stretched with an ingredient known as an adjuvant. "There clearly has been some increase (in capacity), but it's not clear what the increase is," he said.

Neuzil said antiviral drugs could help address any shortfall by treating or preventing the flu, although the medicines do not offer long-term protection.

She said she worried more about vaccine availability for poor countries than for the United States.

"Ninety-five percent of influenza vaccine is made in the U.S. and Europe. As a global community, we also need to consider supply for the low-resource countries," she said.

How to Protect Yourselves from Swine Flu