Officials debate production of H1N1 vaccine

As U.S. health authorities told Congress that they were prepared to mass produce a vaccine against the new H1N1 influenza virus, World Health Organization officials said they would convene an expert committee next week to determine if such production was necessary -- or desirable.

Production of a vaccine against the virus in anticipation of its return next fall might sound like an obvious step, but doing so will sharply limit the amount of seasonal flu vaccine that will be available.
And seasonal flu is a known killer, experts said, leading to an average of 36,000 deaths in the United States each year and tens of thousands more globally.

"We would not want to have no seasonal influenza vaccine," said Dr. Marie-Paule Kieny, director of the WHO Initiative for Vaccine Research.

The 20 vaccine manufacturers worldwide have an annual production capacity of about 900 million doses of seasonal flu vaccine, she said, and that might be stretched to as many as 2 billion doses of H1N1 vaccine. But that would mean abandoning production of seasonal vaccines in plants that switch to the new vaccine.


She also noted that many questions remain about production of an H1N1 vaccine, including how fast the virus will grow in the eggs that are used as a production medium, what size dose will be required, and whether one dose will suffice.

Because the new virus is so different from circulating strains, and the general public has had no previous exposure to it, many experts believe a booster shot will be necessary in additional to the normal vaccination. If that proves to be the case, it will sharply reduce the number of people who can be immunized.

Dr. Anne Schuchat of the Centers for Disease Control and Prevention told Congress that researchers have carried out the preliminary phase of vaccine production more rapidly than expected and, "Should we need to manufacture a vaccine, we can work towards that goal very quickly."

Globally, more than 2,000 cases of H1N1 infection have now been confirmed, with Sweden and Poland becoming the most recent countries reporting a case, bringing the tally to 24 countries.

In the United States, 30 new cases in Arizona, 40 in Illinois and scattered cases elsewhere brought the total to 680 confirmed cases.

More details, meanwhile, began to emerge about the death of a Texas woman, the first U.S. citizen whose death has been linked to the new virus. She has been identified as 33-year-old Judy Trunnell, a teacher in Harlingen, Texas, just over the border from Mexico.

She died early Tuesday after being hospitalized April 19, according to Leonel Lopez, the Cameron County epidemiologist. Trunnell was pregnant when she entered the hospital, and the baby was delivered by cesarean section after she fell into a coma.

Health officials said she had "chronic underlying health conditions," but would not give further details and would not say whether her death was a direct result of the flu.

The only other U.S. fatality was a Mexican toddler who died in a Houston hospital last week.

Dr. Richard Besser, acting director of the CDC, said that at least 35 people in the United States have been hospitalized with H1N1 flu. The median age was 15, with a range of 8 months to 53 years. Seasonal flu normally strikes the elderly and the very young especially heavily, and officials are at a loss to explain this virus' different age distribution -- one that has been observed in Mexico as well.

One much-bruited possibility is that the elderly retain some vestige of immunity from contact with swine flu viruses that circulated two to four decades ago.

As 136 Mexican nationals who had been quarantined in China returned home on an Aeromexico airliner, Chinese officials said they would also release 28 students and a professor from the University of Montreal who had been held in quarantine in Changchun since Saturday. None of them displayed any symptoms of infection.

Also today, the government of Haiti turned away a Mexican aid ship carrying 77 tons of rice, fertilizer and emergency food kits. Mexican officials said the navy ship's crew had been screened and showed no signs of infection, but the Haitian government requested that it come "on another occasion."

The World Health Organization issued new cautions about pigs Wednesday, seemingly contradicting earlier statements that it is safe to consume pork from infected animals.

"Meat from sick pigs or pigs found dead should not be processed or used for human consumption under any circumstances," Jorgen Schlundt, director of WHO's Department of Food Safety, Zoonoses and Foodborne Diseases, told Reuters.

He also warned that humans could possibly become infected from contact with blood from diseased pigs and that workers processing the animals should wear appropriate protective clothing.

But he also conceded that there is no data available about the survival of the virus on meat or on the infectious dose for humans.

Paul Sundberg, vice president of science and technology for the National Pork Board in the U.S., said that Schlundt is technically correct, but added that current rules already prevent meat from sick pigs or those found dead from entering the food system.

He and others also pointed out that the virus has so far not been found in any pigs other than a herd of about 200 animals in Canada who were infected by their farmer and have subsequently recovered.