Chicken eggs for vaccine production

Vaccine production is based on chicken eggs, but more would be needed in a pandemic. Sanofi Pasteur's federal contract will help the company produce eggs year-round. (Sun photo by Christopher T. Assaf / January 26, 2005)

They gathered around a hotel conference table in Howard County, planning for what might be Maryland's worst public health crisis.

The public health and safety experts spun a shocking scenario arising from the threat of an avian flu pandemic from Asia: 12,000 deaths in the state early on, with the possibility of many more later.

More conservative estimates from the U.S. Centers for Disease Control and Prevention suggest 1,600 to 3,700 Maryland deaths and 16,000 hospitalizations. But public health leaders can't be optimists.

"We have to plan for the worst-case event," said Dr. Jean Taylor, who heads Maryland's pandemic-planning efforts at the state Department of Health and Mental Hygiene.

To safeguard Americans against a pandemic that scientists generally agree is inevitable, federal, state and local officials are developing extensive plans encompassing needs such as hospital and mortuary capacity and production of antiviral medication and vaccines. Local health departments have begun identifying locations such as school gyms and community centers that could accommodate temporary hospitals -- space that might be needed for months.

This month, President Bush signed an executive order authorizing use of quarantines for avian flu cases.

Despite the enormous efforts, critics are warning that the federal government hasn't done enough. Among them are Andrew Pavia, chairman of the Infectious Diseases Society of America's task force on pandemic influenza. He told Congress late last month that "the United States is woefully unprepared for a pandemic that might occur in the next few years."

Essential tools

Much of the concern focuses on the nation's capacity to provide antiviral medications and vaccines.

Antiviral drugs like Tamiflu are essential tools in slowing the spread of disease until a vaccine can be developed to immunize people -- a process that can take six to eight months from the time a killer virus is identified. The United States has enough Tamiflu on hand to care for 2.3 million people, significantly less than some other nations.

But federal authorities said substantial progress is being made:

  • The Centers for Disease Control and Prevention have paid $13.9 million for the manufacture and stockpiling of 2 million doses of an experimental vaccine for the H5N1 virus, which has killed millions of chickens and a small number of people in Asia. The vaccine is being tested at the University of Maryland School of Medicine in Baltimore and two other sites. It is intended for research, shelf-life studies and, if approved, possibly for limited human innoculations.

  • To beef up the capacity of the only flu vaccine plant left in the United States, authorities invested $41 million last fall to expand and maintain the chicken flocks used by the company Sanofi Pasteur in Swiftwater, Pa. By September, that will allow year-round production of the millions of fertile eggs vital to vaccine production.

  • Sanofi Pasteur has also won a $97 million contract to develop a technology for vaccine production in a line of human cells, which could reduce by months the time needed to produce a new vaccine.

  • A Swiss maker of antiviral medication has committed to producing it in a new U.S. plant next year.

    This summer, the National Vaccine Program Office will finalize a Pandemic Influenza Preparedness and Response Plan. State health departments are expected to have their plans ready by September.

    But there's only so much the government can do to prepare.

    Despite years of worry about an avian flu outbreak in Asia, virologists don't know for sure which virus they would face in a pandemic, where it would evolve, how deadly it will be or how easily it would be passed from person to person.

    Pharmaceutical manufacturers can't begin making vaccines until that new virus emerges. Even then, they'll need months, while the disease is spreading, to grow the vaccine proteins in fertilized chicken eggs.