Fighting the Flu

By Dennis Clements, MD, PhD

Children never like to get their vaccinations, so I wasn't surprised when eight-year-old Johnny asked me if he really had to have a flu shot every single year.

"I don't like it any more than you do," I said, "but the flu changes every year so you need a new kind of shot every year. Besides, the vaccine does more good in your arm than in the bottle."

He wasn't sure that was a good reason, but finally agreed to take the shot after I told him I get one every year myself.

While kids dread the flu shot, parents dread their getting the flu even more, and with good reason. Influenza affects people of all ages, but it strikes children particularly hard--so it's especially important that we take steps to protect them.

Influenza (commonly called "the flu") visits our community every winter, but it's difficult to predict how bad the flu will be in any particular year. Unlike most other viruses, influenza comes in continually different varieties. The two types we most often see are labeled "A" and "B". These viruses slowly mutate over time so that they are never quite the same when making the rounds in our community from year to year. Particular flu strains are referred to by specific names, such as Influenza A Bangkok or Influenza A Taiwan.

People's susceptibility to the flu varies just as much as the virus. The flu is very contagious--it is transmitted when we ingest or inhale the tiny droplets spread when infected people cough or sneeze--but not everyone who is exposed to the virus will come down with the flu. We have an "immunologic memory" that protects us against diseases we have been exposed to in the past, so those of us in our middle years are less frequently very ill. (There are exceptions. When a new flu strain shows up that almost no one has been exposed to before, look out--the whole population can get sick, as was the case with the Asian Flu, the Hong Kong Flu, and the Spanish Flu, to name a few.) When we get very old, our immunity wanes because it forgets what it has seen before, so the elderly are more susceptible to the flu.

The youngest children who have never been exposed to the illness before are most susceptible. These four-month- to two-year-old children can be sick (and contagious) for up to 10 days with a fever and symptoms that often resemble a bad cold. They may also have diarrhea and sometimes a very high fever. As children age, they remain susceptible to strains of the flu that they have not seen before, so when new strains appear they can still get very sick. Some years strains of influenza A and influenza B both make the rounds, so it is even possible for them to come down with different versions of the flu twice in the same year.

While most will bounce right back, some do not. A hundred and forty American children died from the flu in 2003, and thousands of children every year are hospitalized with flu-related complications--which can include ear and sinus infections, bronchitis, and pneumonia. Very young children, children with asthma, and children with certain other chronic diseases are most likely to experience complications.

Fortunately, there is an easy way to boost your children's immunity against the flu. Just have them immunized every year with the influenza vaccine, which is tailored to fight the particular flu experts expect to see that season. With any luck they can sneak through one year after another without getting sick. What's more, if they don't get sick maybe you won't either.

The ideal time to get the flu vaccine is four to five weeks before the flu arrives. Peak flu season can range from December to March, so we vaccinate from October to January. Occasionally flu vaccine production is delayed but no delay is expected this year. [Editor's note: This column was written before the Oct. 5 announcement that a major manufacturer of the influenza vaccine would be unable to deliver any vaccine to the United States for the 2004-2005 flu season. For updates, please visit the Centers for Disease Control Web site.]

The vaccine is particularly recommended for those over 50 and for children six months to two years old. It is not recommended, however, for children with severe allergic reactions to eggs.

Sometimes parents are concerned that vaccines will make their children sick, but the influenza shot is a "killed-virus" vaccine that cannot cause the flu. If a child does come down with a flu-like illness it is because they were harboring it when they received the immunization. Sometimes the shot may cause their arm to be a little sore but that will be all.

A new type of influenza vaccine that involves getting the vaccine sprayed into the nose is now available. Unlike the shot, the nasal flu vaccine is a live-virus vaccine and may only be given to healthy people between the ages of five and 50 years. You may want to ask your health care provider if your or your child is eligible to get this newer vaccine.

If your child does come down with the flu, there are medicines to help treat influenza. Some are for flu A and some for flu A and B. Liquid preparations are hard to find so generally only adults are treated. Occasionally, though, a physician will feel it is warranted to treat children, and it is possible to do so. Treatment is only effective if given early, and to make things more complicated not all insurance companies cover all preparations for treatment. So check with your insurance company, or you may find yourself with an $80 pharmacy bill.

Good luck this year, and be sure your children get their flu vaccine. It is their best insurance against getting the flu.

Dennis Clements, MD, PhD, is the chief of primary care pediatrics at Duke Children's Hospital.