Experts advise not to vacillate on flu vaccine.

Byline: The health files by Tim Christie The Register-Guard

HERE IT IS mid-November, and you're still trying to decide whether to get that annual flu shot.

Or maybe you've already gotten a flu shot and are wondering if it will do you any good.

State epidemiologists say the 2002-03 flu season should be "average," just as the past two seasons were, barring the appearance of a late mutant strain of the influenza virus.

It's not too late to get a flu shot. If you're still wavering, here are questions to those burning questions about the flu - or influenza, as public health pros prefer to call it - and the vaccine that guards against the virus.

Should I get a flu shot?

Only if you want to avoid spending a week of sick pay on high fever, headaches, body ache and fatigue.

What's the big deal - isn't the flu just like a really bad cold?

Not to the 21 million people, including 500,000 Americans, who died in the infamous Spanish flu pandemic of 1918-19.

Influenza is a disease of the lungs, and can lead to pneumonia. In any flu season, it sickens 10 percent to 20 percent of the population, sends about 114,000 Americans to the hospital each year and leads to about 20,000 deaths (mostly among the elderly), according to the federal Centers for Disease Control and Prevention.

How do they make flu vaccine and how does it work?

There are two main types of flu: type A, which tends to cause more serious illness, and type B, which generally causes milder illness.

Surveillance sites around the world look for new strains of flu types A and B. Every winter, public health officials decide which strains are most likely to reach our shores and should be included in a vaccine for the coming flu season.

The vaccine itself is made from dead particles of influenza cells, with two type A strains and one type B strain.

When the dead virus particles are injected into your body, your immune system recognizes them as something foreign and threatening, and starts producing antibodies to fight the virus, said Mary Durbrow, adult immunization coordinator for the government's Oregon Health Services.

It takes your immune system about two weeks to ready itself for the flu virus, which is why it's a good idea to get a flu shot this month. Flu season typically runs from December to February.

How much protection does a flu shot provide?

The vaccine protects about 90 percent of healthy young adults from the flu, but is only 30 to 40 percent effective in preventing illness among frail, elderly people, according to the CDC.

Also, if you get a flu shot and still get the flu, your illness is likely to be far less severe than if you'd gone without protection.

Will a flu shot make me sick?

Not likely. There's a lot of confusion about this, Durbrow said, because "the flu" has become a catch-all term to describe all kinds of ailments.

"When we get runny noses and cold symptoms, it gets lumped together with the flu," she said. "Flu refers to influenza, which is caused by the influenza virus. The shot protects us against influenza."

There's no way dead virus particles in a vaccine can cause the flu, she said. Fewer than 1 percent of people who get a flu shot will report symptoms such as fever, chills, malaise and aches. Studies indicate that such symptoms are no more common than in people who get a placebo injection.

A more likely explanation for the phenomenon is that flu shots are given at a time of the year when many cold viruses are also circulating, Durbrow said. It is most likely a coincidence that a person will develop cold symptoms after receiving a flu shot.

What if I'm allergic to eggs or had severe reaction to the vaccine in the past?

Then you should probably pass on getting a flu shot. Talk to your doctor.

How do I know if I've got the flu and not a cold?

If you've got the flu, you'll know it. If you're not sure, it's probably a cold.

"You get sick so fast with influenza you can almost name the hour you got the fever," Durbrow said.

You know you've got the flu if illness comes on quickly and severely; you have fevers of 102 to 104 degrees; you suffer severe headaches and severe muscle ache. You should get better in a few days, but tiredness and cough can last two weeks or more.

Such symptoms as runny nose, sneezing, sore throat and cough are less common with influenza than they are with a cold.

What about `stomach flu'?

No such animal. Symptoms such as nausea, diarrhea and vomiting are uncommon with the flu, except in very young children.

Who is most at risk of influenza?

In short: old people, sick people, young people, pregnant women, people who live in long-term care facilities, health care workers, and anyone who lives or works with any of these people.

So if I'm a healthy adult, I don't need to get a flu shot, right?

Wrong. Unless you don't mind getting severely ill. The CDC recommends flu shots for all adults 50 and older.

What about children?

For the first time, this year the CDC has "encouraged" that children between the ages of six and 23 months be vaccinated. That's because children under age 2 are just as likely to be hospitalized as people 65 and older for flu symptoms, Durbrow said.

The CDC's "encouragement" falls short of a full recommendation for children, but Durbrow said she expects that to happen in the next few years.

Are we overdue for an influenza pandemic?

"We're definitely overdue," said Dr. Fred Hoesly, an epidemiologist specializing in acute and communicable diseases at Oregon Health Services.

Pandemics happen every 10 to 40 years. Four flu pandemics have occurred in the past 100 years: 1889-91, 1918-19, 1957-58 and 1968-69.

"That's why there's such a push to develop pandemic plans," Hoesly said.

Many states, including Oregon, are developing contingency plans for dealing with the next influenza pandemic. Hoesly points to the problems that vaccine manufacturers have had in past years producing adequate supplies of flu vaccine in time for flu season. Making vaccine takes about nine months and is a tricky business because it requires growing live viruses, which don't always cooperate.

What could cause a pandemic?

The various flu strains undergo small changes each year. But occasionally the virus mutates into an all-together new virus for which there is no natural immunity, Hoesly said, "and that's when you have a real problem."

We've had scares in recent years, notably in 1997, when a new strain of bird flu emerged in Hong Kong. Six of the 18 people who got it died.

"It raised a real fear of pandemic spread," Hoesly said, but the virus lacked the ability to spread easily from person to person.

If it's any comfort, know that public health pros around the world are constantly on the lookout for new strains and the risk they pose.

Where did the word `influenza' originate?

From 15th century Italy, where an epidemic was attributed to "influence of the stars."

Tim Christie covers health and medical issues. Call 338-2572 or e-mail [e-mail].

2003 PUBLIC FLU SHOT CLINICS

Cost: Flu shots cost $15; pneumonia vaccine is available for $18 per shot. Fees are payable at the time of the shot. Medicare recipients must bring their Medicare cards so clinic officials can bill for the shots.

Today: 9 a.m. to 4 p.m., Wheeler Pavilion, Lane County Fairgrounds, 796 W. 13th Ave., Eugene

Every Wednesday: 1 p.m. to 4 p.m., Lane County Public Health, 135 E. 6th Ave., Eugene

This Thursday: 9 a.m. to 11:30 a.m., Campbell Senior Center, 155 High St., Eugene

This Friday: 9 a.m. to 4 p.m., Willamalane Senior Center, 215 C St.,Springfield.

Dec. 4: 8 a.m. to noon, Florence Events Center, 715 Quince St.

Information: Call Lane County Public Health at 682-4013 or the Flu Line at 682-4181 for latest flu clinic updates.

- The Register-Guard