Stopping a Flu Pandemic

During the winter of 1918-19, only months after the end of World War I, much of the world was ravaged again, this time by the “Spanish flu” that killed an estimated 40-50 million people. Normal societal functions, including commerce, education and government services, were virtually shut down in many places.<?xml:namespace prefix = o ns = “urn:schemas-microsoft-com:office:office” />


We know now that this pandemic strain of influenza was so destructive not because it was particularly infectious—that is, transmissible from one individual to another—but because it had an unusually high mortality rate. The reason was an enhanced ability to attack the cells of the lung, often causing massive inflammation and fluid accumulation. Many victims drowned in their own secretions, often within a couple of days of the onset of symptoms.


Experts are virtually certain that another flu pandemic will eventually occur, either naturally or as a result of laboratory strains developed as bioterror weapons. Unless we take appropriate countermeasures, international travel by recently infected, contagious individuals could make our global village even more vulnerable than it was nearly a century ago. The consequences to public health—and to the world's business activities—could be devastating.


Such an outbreak could, in theory, be controlled with vaccination and the use of antiviral drugs, but current vaccine production methods and stockpiles of antiviral medications are woefully inadequate for a genuine emergency.


The limitations of current methodology slow our response to the constantly appearing new variants of flu virus. Decisions about the viral strains to be included in each season's flu vaccine must be made during the previous winter, and the viruses are then grown in millions of chicken eggs. Some companies are trying instead to grow the viruses in cultured cells, but even with this advance it would still be difficult to respond quickly to a new pandemic strain.


What we really need is a quantum leap in technology: the use of gene-splicing techniques to make so-called “subunit” flu vaccines. Used for two decades to produce Hepatitis B vaccine, this approach involves splicing a single gene from the virus into either bacteria or yeast. These organisms then become mini-factories for synthesizing the viral gene product, which, after being isolated and purified, is used as the vaccine. Early attempts to adapt this approach to flu vaccine have been unsuccessful, and more research is needed. Researchers are also attempting to devise vaccines that make the immune system target viral components that are highly conserved across all strains of flu.


In the meantime, anti-flu drugs—which should also be effective against all variants of the virus—provide an essential complement to vaccines. Assuming that each flu victim would infect two to four more individuals, researchers estimate that giving antiviral medicines prophylactically to 50-75 percent of our population would prevent a pandemic like the one that struck in 1918.


Vaccination to prevent viral and bacterial diseases is modern medicine's most cost-effective intervention. Although their social value is high, vaccines' economic value to pharmaceutical companies is low because of their minimal return on investment and the exposure to legal liability they bring to manufacturers.


The underlying problem is government policies that discourage companies from investing aggressively to develop new vaccines, and that have failed to stockpile antiviral drugs.


The major purchaser of most vaccines, the Centers for Disease Control and Prevention, extracts huge discounts from manufacturers, and arbitrary and excessive regulation also blocks progress. As a result, innovation has suffered and vaccine producers have abandoned the field in droves, leaving only four major manufacturers and a few dozen products. There are only two producers of injectable flu vaccine for the <?xml:namespace prefix = st1 ns = “urn:schemas-microsoft-com:office:smarttags” />U.S. market, for example.


To correct these broad deficiencies, and to stop an evolving flu pandemic in its tracks, the government must take a number of actions: increase funding for basic research on subunit vaccines (which are safer and cheaper and should have shorter development times than conventional ones) and other novel approaches; and stockpile anti-flu medicines. In addition, the CDC must stop demanding discounts that discourage manufacturers, and regulators should pursue agreements on “reciprocity” of approvals so that vaccines and antiviral drugs licensed in certain foreign countries can be marketed in the United States.


In the longer term, Congress could take other steps to improve the climate for vaccine makers, such as offering tax breaks to offset research and development costs; requiring health insurance providers to cover immunizations without the usual deductibles; and stipulating that once the Food and Drug Administration has approved a vaccine, the government would compensate victims of side effects.


These measures collectively constitute a health insurance policy that we cannot do without.