The NIH News in Health
skip navigation
Features
December 2009
(PDF—498 kb)  
 

Don’t Fear the Flu
Arm Yourself with the Facts


 
Cartoon of girl getting flu vaccination.

Scary stories about the 2009 H1N1 flu are sure to get your attention. A lot of people are worried and confused as this new virus spreads across the globe. But it’s not fundamentally different from the seasonal flu we see every year. Learn the facts about H1N1 and how to prevent it from striking your family.

The truth is, flu—or influenza—can always be deadly. Each year, the seasonal flu kills more than 36,000 people nationwide and hospitalizes 200,000. Now we’re faced with the first pandemic flu in over 40 years.

“Seasonal flus change slightly from year to year,” explains Dr. Anthony S. Fauci, director of NIH’s National Institute of Allergy and Infectious Diseases. Once your immune system encounters a virus, it learns to recognize and block it, so it won’t make you sick again. Each year, seasonal influenza viruses change a little bit to evade your immune system. This slow “drifting” from year to year can go on for decades.

Pandemic flu comes rarely—only 3 times in the 20th century. Instead of a little drift, it’s caused by a sudden major shift. That can happen when a virus jumps from an animal to humans. Most people have no immunity to the new virus, since our immune systems haven’t seen anything like it before.

The 2009 H1N1 flu has some components from flu viruses known to affect pigs. That’s why its original name in the media was swine flu. But it also has components from human and bird flu viruses. The virus was first diagnosed in Mexico in April 2009. It rapidly spread throughout the world and became pandemic.

Since the world hasn’t seen a flu pandemic since 1968, it’s easy to see why public health officials are tracking this new virus so closely. According to the Centers for Disease Control and Prevention, at least 14 million Americans have probably been infected with this new virus so far.

The new pandemic influenza virus causes symptoms similar to all flus: fever, cough, sore throat, runny or stuffy nose, body aches, headaches, chills and fatigue. Some people have vomiting and diarrhea. So far, however, the virus seems no more deadly than other flus. “In general, it’s a mild to moderate illness,” Fauci says. “But unlike the seasonal flu, which predominantly threatens the elderly, this flu predominantly threatens young people, pregnant woman and people who have underlying conditions,” Fauci says.

“There’s nothing particularly unusual about this virus in terms of transmission,” explains Dr. Ira M. Longini Jr. of the Fred Hutchinson Cancer Research Center and University of Washington, Seattle. “It’s within the bounds of usual flu, but people under 50 are unusually susceptible.”

The reason for that, Fauci explains, is that the immune systems of younger people are less experienced. “The older you are, the greater the chance that in your lifetime you were exposed to something that had some degree of resemblance to the pandemic strain,” he says.

That’s why it’s so important for young people to get vaccinated. Vaccination is the best protection against flu. Vaccines contain pieces of viruses to “teach” your immune system to recognize and attack the real viruses as soon as they enter your body.

Each year, scientists look at the influenza viruses emerging at the end of the flu season. Then they begin making a vaccine, hoping to match the viruses that will emerge in full force the following fall and winter. “You can predict with accuracy about 85% of the time at the end of a given flu season what you’re going to see the next flu season,” Fauci says.

What you can’t predict is a pandemic flu strain, like this one, that enters the population without warning. Researchers began working on a new H1N1 vaccine as soon as they realized there was danger of it causing a pandemic. That’s why there are 2 different flu vaccines this year—one for the seasonal flu and one for the new pandemic flu.

“Right now with the pandemic flu, we have a perfect match,” Fauci says. “We’ve just got to get the vaccine out.”

There may be a lot of misunderstanding out there about the H1N1 vaccine, but Fauci explains, “The vaccine for H1N1 is made by the same companies that make the seasonal flu vaccine—using the same processes, the same materials, the same techniques. And the seasonal flu vaccine has a very, very good track record for safety in tens, if not hundreds, of millions of doses given over several decades.”

If you’re still sitting on the fence, Fauci says, “We know that even though there’s a very small chance that you’ll get into trouble with the flu itself, the chances—particularly if you’re someone at a higher risk—of your getting into trouble with the virus are overwhelmingly greater than the risk of the vaccine.”

Longini says that it’s important to get vaccinated, even though the pandemic may be past its peak in some areas of the country. “There’ll be continued transmission throughout the flu season, so it’s very important to get vaccinated. It’s not going away.”

Fauci and Longini say the pandemic H1N1 this year will probably be the seasonal virus in the future, changing a little bit from year to year. “We’ll be making vaccines to slightly different variants of this for years to come,” Longini says.

So get vaccinated. Remember, you need 2 different vaccines this year to be fully protected from both seasonal and pandemic flu. Also, try to avoid close contact with sick people, and avoid touching your eyes, nose or mouth. Wash your hands often with soap and water, or use alcohol-based hand cleaners.

If you do get sick, get plenty of rest and drink clear fluids like water and soup broth. Those 5 years of age and older can take medicines such as acetaminophen (Tylenol) and ibuprofen (Advil, Motrin, Nuprin) to relieve symptoms. Don’t give aspirin to children or teenagers who have the flu; this can cause a rare but serious illness called Reye’s syndrome.

If you have flu, help keep it from spreading. Cover your nose and mouth with a tissue when you cough or sneeze and throw the tissue away after you use it. And don’t go to work or school while you’re sick. Stay home until at least 24 hours after you no longer have a fever (100°F or 37.8°C) without the use of a fever-reducing medicine.

to top

Definitions icon Definitions

Immune system
The system that protects your body from viruses and other microscopic threats.

Pandemic flu
A new flu strain that spreads quickly to create a world-wide epidemic (a pandemic).

Seasonal flu
The flu outbreaks that occur yearly, usually in late fall and winter.

Wise Choices iconWise Choices

Warning Signs

Get medical care right away if you notice these symptoms:

In children:

  • Fast breathing or trouble breathing
  • Bluish skin color
  • Not drinking enough fluids
  • Not waking up or not interacting
  • Being so irritable that the child does not want to be held
  • Flu-like symptoms improve but then return with fever and worse cough
  • Fever with a rash

In adults:

  • Difficulty breathing or shortness of breath
  • Pain or pressure in the chest or abdomen
  • Sudden dizziness
  • Confusion
  • Severe or persistent vomiting

Links iconWeb Sites

Influenza (Flu)

flu.gov

 
 
     
   
 
 
NIH logo National Institutes of Health (NIH)
9000 Rockville Pike
Bethesda, Maryland 20892
DHHS logo Department of Health and
Human Services
  Office of Communications and
Public Liaison