Flu Season Winding Down, But Not Over

Q:  Can I get the flu even if I've been vaccinated? I had my flu shot, but for the past few days I've had a headache, I ache all over, and I'm exhausted. At first, I was sick to my stomach, couldn't eat and had diarrhea, but these symptoms went away after a day or so.

Also, I'm worried about my newborn getting the flu, but now our clinic has run out of shots. What should I do?

A:  The flu shot, in the best of circumstances, prevents the flu about 80% of the time. It takes up to two weeks after the shot for your body to make the antibodies that protect you from the flu. This year, the predominant flu virus is slightly different than what was predicted and so the shot may be less effective.

But it sounds like you don't actually have the flu. The flu, or influenza, usually causes headache, body aches and extreme tiredness like you have, but infected people often also complain of high fever, dry cough, sore throat and runny nose. Stomach symptoms such as nausea, vomiting or diarrhea are uncommon in adults, although they can be common in children.

The "stomach flu" is not really due to the influenza virus at all, but to several different kinds of viruses. There are lots of viruses that mimic the classic influenza symptoms; in fact the Centers for Disease Control and Prevention (CDC) reports that only about one-third of those tested for the flu really have it. Many stomach problems, especially diarrheal illnesses, are actually caused by food-borne bacteria.

What you can do now are the same things you should do for any virus: get plenty of rest, drink lots of fluids and try over-the-counter pain relievers such as acetaminophen (Tylenol). Most viruses, including the flu, last about a week and healthy people usually get better without any specific therapy.

Newborns are at risk for flu complications, but the vaccine is not approved for children younger than 6 months. For healthy people, an alternative is the nasal spray flu vaccine. You may want to ask your doctor about this. You also may call your local health department; they often know where vaccines are available in your area.

Many clinics, including my own, save some remaining flu shots for people most at risk for complications from the flu - healthy people over age 65, children aged 6 to 23 months, pregnant women in their second or third trimester, and people with underlying chronic conditions such as lung disease or diabetes.

It is a good idea to follow general common-sense measures to decrease your chance of catching the flu, or any other virus, for that matter. Nancy Kreuser, the health officer for the City of Wauwatosa Health Department, gave me a good list (also available on the CDC Influenza website.

• Avoid close contact with people who are sick.
• Stay home when you are sick (to prevent others from catching your illness). As much as possible, keep your distance from others if you can't stay home.
• Cover your mouth and nose with a tissue when coughing or sneezing.
• Wash your hands regularly to get rid of germs.
• Avoid touching your eyes, nose or mouth so any germs on your hands do not enter and infect your respiratory tract.

For people with medical problems, the flu vaccine tends to be somewhat less effective than it is for healthy people. Even with its imperfections, though, the flu shot remains the best way to prevent the flu, particularly in those at high risk for complications. High-risk individuals may need to see a doctor if they think they have the flu; their physician may want to test them for influenza or prescribe an anti-viral medication.

For more information on this topic, see the HealthLink articles Flu Time Again, with a Twist: Vaccine by Nasal Spray and Season Has Started, But Flu Shot Still a Good Idea.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices internal medicine at the Froedtert & Medical College General Internal Medicine Clinic - East. Her column also appears in the Milwaukee Journal-Sentinel.