Following last winter's shortage of critical influenza vaccinations, the federal government is considering expanding the number and types of vaccines currently held in reserve for emergency use.

The goal is to stop unanticipated shortages of frequently used vaccines and prevent disruptions in supplies, but officials responsible for making the shots available say stockpiling vaccines is easier said than done.

"This is a complex problem that needs some very innovative thinking to address and resolve," said Stephen Cochi, director of the National Immunization Program at the Centers for Disease Control and Prevention (search).

In fact, the CDC already maintains a stockpile of vaccines, but it contains only a small number of doses. Since 1983, the stockpile has been tapped on at least nine occasions, most recently last year to manage a measles outbreak in the Marshall Islands.

According to Cochi, approximately 226 million doses of vaccine were distributed in 2002. Two-thirds went for typical childhood vaccinations like polio, diphtheria and tetanus. Of the remaining third used by adults, the majority went to flu prevention.

Last winter, America faced massive shortages in the flu vaccine, primarily due to fatalities early in the season that drove a large number of people to the doctor. End of winter statistics by the CDC showed that the number of deaths was about average compared to other years. 

Nonetheless, in recent years, shortages have occurred in most childhood vaccines and in adult vaccines against influenza, tetanus and pertussis, or whooping cough. Now, a shortage of the new childhood vaccine, pneumococcal conjugate (search), which can prevent meningitis and blood infections, is forcing officials to reconsider the supply and demand chain needed to protect Americans from contagious and often life-threatening illnesses.

"Shortages that we have experienced have not led to gaps in coverage, but what it has led to is delays in age-appropriate vaccines, leaving these children unprotected," Cochi said.

Industry leaders recognize that large upswings in demand are difficult to meet, and acknowledge that any problem with manufacturers can cause a serious delay in the distribution of supplies. The United States has only four major manufacturers of vaccines, and some of those drugs are produced by just one company.

As a result, if one firm has production problems or exits the market, supply problems can quickly mount. Another firm would find it difficult to fill the void because the average vaccine takes nine to 15 months to manufacture.

"If something happens, one can't turn on a dime," William Egan, acting director for the Office of Vaccines in the Food and Drug Administration (search), told an audience at the American Enterprise Institute last week. "With 10, 15, 20 manufacturers, the impact of any problem would be blunted."

Egan cautioned, however, that an increase in the number of manufacturers would drive up prices since companies would have higher overhead, including more plants and equipment spread over a wider territory, but would produce fewer vaccines, earning them less revenues.

Expanding the number of producers may not be so easy, either. In the past, exposure to lawsuits caused many companies to exit the field. The problem has been largely eased by Congress, which in 1988 established the National Vaccine Injury Compensation Program (search), a no-fault alternative to the traditional tort system for resolving vaccine injury claims.

However, vaccine companies are still unhappy about what they say are burdensome regulations and an unattractive profit margin. Vaccines are not a big profit maker, said Paul Offit, chief of infectious diseases at Children's Hospital of Philadelphia.

"It's something [pharmaceutical companies] could drop pretty easily," said Offit, who added that a shift in research and development is moving away from vaccines.

"I fear for new vaccines ... I think vaccine R-and-D is clearly decreasing."

In September 2002, the General Accounting Office, the investigative arm of Congress, recommended that the national stockpile be expanded and regulations be simplified.

Government officials and congressional lawmakers have begun pursuing the establishment of a large vaccine reserve, but while some say it's a promising step, building a large stock faces several obstacles, including regulatory difficulties.

"Congress has set aside the money. Unfortunately we are delayed by new SEC rules," said Philip Hosbach, vice president of the pharmaceutical manufacturer Aventis Pasteur (search). "You'd think it would be a no-brainer to make an exception for vaccines ... It should be resolved in the interest of public health."

Another challenge is that most vaccines have a relatively short shelf life and so the stockpile must have a "dynamic inventory," meaning it must be regularly rotated. In addition, a flu vaccine stockpile would not be effective because a fresh vaccine is needed every year.

A stockpile would create an artificially large marketplace since more drugs would need to be produced just for the inventory. Maintaining that stockpile would also be expensive, Egan said.

"We can increase capacity by buying it and throwing it away. It's a societal question: Do we want to do that?"

Added to all that, government officials have expressed concern that the public does not place enough weight on the value of vaccines.

Cochi said he is worried about "society's low valuation in a relative sense of preventive measures."

It is "difficult to get society to understand that an ounce of prevention is worth a pound of cure," he said.