PHILADELPHIA (AP) -- Despite the cost, even healthy adults benefit from an annual flu shot because they don't lose as much work time and they spend less on treatment, according to a study.

Researchers also found that once people get the flu, antiviral medicine started within 48 hours of seeing symptoms was also worth the expense in terms of making the patients feel better and getting them back to work, according to the study in Tuesday's Annals of Internal Medicine.

"Given that typically the complications of influenza within the healthy population are so low, it was somewhat surprising," said Dr. Patrick Lee, a Stanford University resident and the study's lead author.

The government currently recommends the vaccine only for the elderly, the chronically ill and pregnant women, though it is available to others who want it.

The researchers stopped short of recommending that the general population get vaccinated for the flu, citing recent vaccine shortages that surely would worsen in such a case.

On average, a person who comes down with the flu loses 2.8 days at work, meaning about dlrs 398 in lost wages, the study concluded, based on previous studies and Labor Department statistics.

Researchers said that visiting a doctor and getting a flu shot would save about dlrs 30. Using one of three symptom-shortening antiviral medications resulted in similar savings.

While flu vaccine is beneficial to healthy adults and may get them back to work sooner, the priority should be vaccinating more of the highest-risk people, flu expert Dr. Carolyn Bridges at the federal Centers for Disease Control said.

"When you look at vaccination of healthy adults, the bulk of economic benefit is decreased absenteeism; the benefit for the elderly is reduced medical costs and fewer complications that require hospitalization," she said. "That's something important we need to consider when we're allocating our resources."

The study's authors acknowledged a potential drawback to the research: It used computers to simulate the impact of a flu season on a "virtual" group of healthy people between 18 and 50, using statistics on flu severity and treatment efficacy from previously published research.

However, Lee said, flu strains, severity, location and timing vary so widely from year to year that a computer model likely provides a better snapshot than a real-world analysis.

In an average year, more than 100,000 Americans are hospitalized with the flu and about 20,000 die from flu-related complications, according to the CDC.

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