Influenza Vaccination or Antiviral Treatment for Healthy Working Adults: An Economic Analysis

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The summary below is from the full report titled "Economic Analysis of Influenza Vaccination and Antiviral Treatment for Healthy Working Adults." It is in the 20 August 2002 issue of Annals of Internal Medicine (volume 137, pages 225-231). The authors are PY Lee, DB Matchar, DA Clements, J Huber, JD Hamilton, and ED Peterson.

What is the problem and what is known about it so far?

Influenza is a virus that causes the flu. Flu symptoms include fever, sneezing, coughing, muscle aches, and exhaustion. Flu is more severe than the common cold, keeps people from their normal activities for up to a week or longer, and can be complicated by bacterial infections, such as pneumonia. Experts recommend flu vaccine to prevent infection in older people and in people with diseases that put them at risk for having a complicated course of flu. Treatment of flu generally involves rest, fluids, and medication to decrease fever and aches. However, antiviral medicines can shorten the course of flu when patients take them within 24 hours of developing symptoms. Available antiviral medicines for treating flu include amantadine, rimantadine, oseltamivir, and zanamivir. Although vaccination is an option for anyone, regardless of age or disease, recommendations do not specifically encourage healthy adults under the age of 60 to get flu vaccine. It is unclear whether the benefits of antiviral medicines for flu are worth the side effects and costs.

Why did the researchers do this particular study?

To compare the costs and benefits of flu vaccination and of antiviral medicine in healthy, working adults.

Who was studied?

Rather than studying actual patients, the researchers used computers to simulate what would happen during a flu season to a "virtual" group of healthy patients aged 18 to 50 years.

How was the study done?

The researchers used published information to estimate what might happen (and how much it would cost) if patients did or did not get vaccinated and, if they did get the flu, received one of three antiviral medicines (rimantadine, oseltamivir, or zamamivir) or no antiviral medicine. They put these estimates into a computer model and calculated the costs and benefits for each of the eight potential options for vaccination and treatment. They did not include amantadine because it has more side effects than the other medicines.

What did the researchers find?

All of the vaccination options were more beneficial than those that did not include vaccination. Vaccination with rimantadine if flu developed was the most attractive option in terms of costs and benefits. However, the benefits of all of the antiviral treatment options appeared equal to or greater than their costs in most situations.

What were the limitations of the study?

This was a computer model and may not accurately reflect what would happen in real life. Further studies are necessary to determine which of the available antiviral treatment options is most favorable in economic terms.

What are the implications of the study?

The costs of flu vaccination of healthy, working adults appear to be worth the potential benefits. The benefits of antiviral medicine for healthy working adults who get the flu despite vaccination seem to be worth the cost.