By Kristine Severyn, R.Ph., Ph.D.

Every autumn the elderly and other high risk groups are encouraged to receive influenza vaccine (flu shots). Congress authorized Medi care funding for flu shots in 1993, believing that vaccination costs are less than hospitalization costs related to influenza complications. Was Congress misled when it authorized this $80 million per year Medicare flu shot entitlement? Have vaccine recipients been misled?

Although influenza is associated with more disease, hospitalization, and death in "at risk" populations, no adequate controlled studies exist which prove that influenza vaccine reduces the incidence of influenza in these groups.

CDC CRYSTAL BALL

Influenza virus strains mutate, necessitating a new vaccine each year. Technicians affiliated with the Centers for Disease Control and Prevention (CDC) collect influenza viruses from pigs and people in foreign lands, e.g., China.

CDC personnel then attempt to predict which viruses will infect people in the United States the following year—the CDC crystal ball. These CDC-selected viruses are distributed to vaccine manufacturers early in the year for influenza vaccine production for administration that autumn.

Predicting which influenza viruses from China, for instance, will infect people in Dayton, Ohio, a year later involves a fair amount of guesswork. Flu shot history is replete with examples of poor matches between influenza viruses in the vaccine and those actually infecting people.

For example in the 1994-1995 flu season, the CDC reported that 43 percent of isolated influenza samples for the predominant virus type A(H3N2) were not similar to that in the vaccine. Likewise, for another type A virus (H1NI), 87 percent of samples were not similar to that in the vaccine. According to a worldwide influenza activity update in the Aug. 8, 1995, Morbidity and Mortality Weekly Report (MMWR), 76 percent of isolated samples of influenza type B were not similar to the influenza in the vaccine.

The CDC crystal ball also erred during the 1992-1993 influenza season when, as reported in the Sep. 1, 1993, edition of MMWR, 84 percent of the isolated influenza samples for the predominant virus (A(H3N2)) were not similar to the virus in the vaccine.

WISHFUL THINKING

Despite its poor track record in predicting which influenza viruses will infect communities, the CDC admitted Feb. 26, 1999, in its nationally broadcast program, "Preparing for the Next Influenza Pandemic," that influenza vaccine is "approximately 70 percent" effective in preventing influenza in "healthy persons less than 65 years of age" if "there is a good match between vaccine and circulating viruses."

Depending on the study cited vaccine efficacy actually ranges from a low of 0 percent to a high of 96 percent. And, as illustrated above, the CDC often finds it difficult to match vaccines with circulating viruses.

According to the CDC, influenza vaccine efficacy drops to 30 percent to 40 percent among the elderly—this group being the main "target" for flu shots. CDC attributes lack of influenza vaccine efficacy in the elderly to their "decreased immunologic re sponse."

Past studies by NH Arden, et al, of type A(H3N2) influenza vaccine in nursing home patients yielded an average of only 27 percent efficacy with four studies demonstrating vaccine efficacy at 0, 2, 8 and 9 percent. Poor vaccine efficacy can even occur when the vaccine virus is "essentially identical" to that virus which is causing the outbreak. For influenza B vaccine, studies conducted by Arden range from 0 percent to 36 percent effective, averaging 21 percent.

DAMAGE CONTROL

To justify its recommendation that all elderly persons receive flu shots, the CDC asserts in an April 21, 1995, MMWR article that, even though the vaccine does not prevent influenza very well, "the vaccine can be 50 percent to 60 percent effective in preventing hospitalization and pneumonia and 80 percent effective in preventing death."

This optimistic scenario is clouded by results of the congressionally mandated $69 million 1988-1992 Medicare Influenza Vaccine Demon stration Project. This study, intended to promote Medicare-funded flu shots, yielded, according to a 1993 MMWR report, a disappointing 31 percent to 45 percent effectiveness "in preventing hospitalization for any pneumonia" during three influenza seasons.

Results for the 1989-1990 season were described as "mixed at best," with "Medicare payments . . . significantly higher for those who had been vaccinated," noted Kidder and Schmitz in the 1993 report Options for the Control of Influenza II.

Government agencies "calculated" an economic benefit of flu shots to Medicare by manipulating numbers in a computerized simulation until desirable results were obtained. The CDC reported in 1993 that its theoretical assumptions did not include all vaccine-related costs. In 1994 and 1995, The New England Journal of Medicine published medical studies with similar economic claims for flu shots that had been funded by a vaccine manufacturer.

Several studies and government projections from the Department of Human and Health Services confirm that, with or without a flu shot, pneumonia and influenza hospitalization rates for the elderly are less than 1 percent during the influenza season. This means that, regardless of vaccination status, more than 99 percent of people weather a bout of flu without requiring hospitalization. Even the past director of CDC's National Immunization Program, Dr. Walter Orenstein, reported at a 1981 influenza conference that the "at risk" population for influenza complications is small."

Considering that more than 90 percent of pneumonia and influenza deaths occur in persons 65 years of age or older, but that about 65 percent of all deaths (from any cause) occur in this age group anyway, it is nearly impossible to prove if flu shots significantly increase life expectancy in the elderly. Indeed one study of elderly Medicare patients in Ohio and Pennsylvania, published in Options for the Control of Influenza II, showed "no demonstrated effect of influenza vaccine in preventing death or limiting the length of hospital stay."

Health authorities in other countries do not share the U.S. public health community's enthusiasm for influenza vaccine. At one CDC-sponsored influenza symposium a British researcher stated: "The [influenza vaccine] recommendations are strong in certain countries, but weak in others, since not all authorities are convinced of the benefit of immunization."

He deplored the "unsatisfactory situation" of poor influenza vaccine efficacy which "compares unfavorably with other influenza vaccines." Even CDC officials confessed that "influenza vaccines are still among the least effective immunizing agents available, and this seems to be particularly true for elderly recipients."

Congress and the American taxpayer have been defrauded about the alleged advantages of flu shots.