The editorial by Dr. Arnold S. Monto, a noted epidemiologist, accompanies an article by Carolyn Buxton Bridges of the Centers for Disease Control and Prevention who assesses the cost of worker absenteeism during the 1997-98 and 1998-99 flu seasons. Bridges concluded that vaccinating healthy working adults younger than 65 can reduce lost work days and reduce physician visits, but it might not provide overall economic benefits in most years.

Monto compares the Bridges study with one conducted by Kristen Nichol of the University of Minnesota. In 1994, Nichol measured the economic implications of widespread use of the flu vaccine in the United States and showed the vaccine saved business $46.85 per vaccination.

“Despite the differences in these studies, there is no denying that health care workers and industry involved in work-place vaccination programs should consider developing strategies to prevent influenza in healthy working adults,” Monto writes in the editorial.

The delay in delivery of the vaccine is in part attributed to manufacturers who have had difficulty growing one of the strains. There also have been problems in the FDA approval process. The vaccine is not expected to be available in most places until mid-November.

The Centers for Disease Control and Prevention asks that vaccines be administered first to the elderly, people with weak immune systems, people with cardiovascular and pulmonary problems, health care workers, pregnant women and other high risk populations. The vaccine will be made available to others later in the season after the at-risk populations receive the vaccination. The delay in making the vaccine available to healthy populations might be a disappointment to employers, especially some large employers that traditionally offer the vaccine to workers, Monto said.

The vaccinations were “viewed in part as a way to reduce absenteeism, which might occur explosively during a large outbreak, but also as a way of increasing employee job satisfaction,” he writes in the editorial.

Measuring the cost effectiveness of flu vaccines can be tricky, Monto said. In most cases, the vaccine has its greatest impact among the elderly who are more prone to developing complications from the flu. But they are less likely to work. Also, the cost effectiveness of the flu vaccine is measured against the severity of the flu season, which differs each year. In some years, although rare, the strain of influenza and the vaccine do not match so there is no economic benefit. So, comparing cost effectiveness from year to year is not always a fair comparison, Monto said.

“Each influenza outbreak will be different in intensity, and most of these studies were carried out over a limited time period. In addition, the economic impact of influenza in healthy adults is far different from that in the elderly. Much of the benefit comes not from preventing expensive complications, but from time lost in the work place and the home. Simply stated, the vaccine has to be given every year, and unless there is much illness to prevent, the costs outweigh the benefits,” he writes in the editorial.

The vaccines are designed to target three different strains of the flu. If vaccine developers select the wrong strain, then costs will outweigh benefits. FluMist—the live vaccine developed by Hunein Maassab of the University of Michigan—has been proven to work against both Type A and B and may be expected to be associated with greater cost effectiveness once it is approved for use by the FDA possibly by as soon as the 2001 flu season.

Monto points to another avenue of defense. In the absence of the flu vaccine, physicians could prescribe Relenza or Tamiflu, two drugs introduced last year. While these drugs are designed to ease and shorten the duration of the influenza after diagnosis rather than preventing the flu, Monto, who conducted some of the clinical trials of Relenza, said that studies have shown both drugs show signs of preventing the flu, but they have not yet been approved by the FDA for use as a vaccine.

These new drugs “also have been demonstrated to be as effective as vaccine in prophylaxis (prevention), and not to be affected by changes in circulating virus. The new interventions have given us unprecedented opportunities to prevent and treat influenza,” Monto writes.

Financial disclosure: Monto has received research grants from GlaxoWellcome and Hoffmann La Roche. He is a consultant to both as well as to SmithKline Beecham.

public healthArnold S. MontoUniversity of Minnesotalive vaccineRelenza