FLU VIRUSES Experts set to discuss plans for pandemic

The last worldwide pandemic was in 1968.
LONG ISLAND NEWSDAY
When public health officials and vaccine manufacturers convene in Geneva on Thursday, they'll keep an eye on the past as they try to anticipate the future.
Their goal: to plan for the eventuality of a worldwide flu pandemic -- a global outbreak on the scale of the deadly Spanish flu of 1918. It is an issue considered urgent because of the persistent presence of bird influenza in Asia.
To date, 44 cases of bird flu and 32 deaths have occurred in humans there, including a case in which a killer flu virus may have been transmitted from a nursing mother to her infant daughter. Scientists remain flummoxed about the ability of such strains, now under study, to efficiently jump the species barrier. But they say that if it turns out humans can effectively transmit the infection to each other, the stage is set for a rapid spread.
The World Health Organization scheduled the Geneva meeting, saying there is more evidence now than in the recent past that a global flu pandemic can develop.
What it means
Pandemic is a term referring to widespread infections occurring throughout the world. An epidemic, by contrast, refers to a widespread outbreak but without the global impact.
Experts at the summit are expected to confront a chilling fact: No one has yet developed a vaccine against the type of flu viruses capable of causing a pandemic.
Representatives will attend from 16 vaccine manufacturers and public health agencies from the United States, Europe, Japan, Russia, Australia and other industrialized nations.
Pandemics have circled the globe in 1968, 1957 and, in the most devastating of all, 1918, when the Spanish flu killed millions around the world. It led to the deaths of nearly 600,000 people in the United States during the 1918-19 season, said Dr. Ben Schwartz, senior science adviser for the National Vaccine Program Office at the Centers for Disease Control and Prevention. An estimated 40 million people died worldwide.
"The impact of a pandemic can be catastrophic but at the same time, not inevitably so," Schwartz said. Indeed, there were far fewer deaths in the global flu pandemics of 1957, with 70,000 deaths, and 1968, when 34,000 people died.
Pandemics, like flu transmission in ordinary seasons, depend on a host of variables -- including the virulence of the particular pathogen.
"So the magnitude of the next one cannot be predicted with any degree of certainty," Schwartz said.
Using caution
Experts are poised not to take any chances.
A WHO spokeswoman in Washington said the summit is driven by the presence of a flu strain in Southeast Asia, dubbed H5N1, "which is creating more opportunity for new strains to emerge. That's one of the drivers for having the discussion now."
Schwartz said that the H1N1 strains that have swept around the globe since 1918 are no longer linked to pandemics because people have developed enough immunity to fight them -- even without vaccination.
Reporting on U.S. pandemic flu preparations last month, Schwartz said preparations against an H5N1 include increasing the nation's cache of antiviral drugs in the National Strategic Stockpile. Millions of doses, federal health officials say, are being added.
Antivirals, such as oseltamivir (Tamiflu) or amantadine (Symmetrel), zero in on surface proteins of flu viruses and block their ability to replicate. The drugs can be used to shorten the course of the flu or prevent it altogether. Four such medications have been approved by the Food and Drug Administration since 1976.
Previous plans
Pandemic flu preparedness is not a new concept in the United States. The first such plans were drawn up in 1978 after the expected 1976 swine flu outbreak fizzled.
Dr. George Curlin, deputy director of microbiology and infectious diseases at the National Institutes of Health, said a key drawback today is the lack of a coordinated global effort to develop suitable vaccines. Manufacturers would have to respond with the ability to produce billions of doses rapidly, once a circulating pandemic strain is identified.
As a result, the United States is investing $50 million to study new production techniques that avoid cumbersome and lengthy manufacturing of vaccines in fertilized chicken eggs. Such old production methods date back a half century, Curlin said. Newer ones are needed to accommodate surge capacity, when billions of doses would be required. Currently, vaccine makers produce 300 million doses of flu vaccine worldwide for an ordinary flu season.