What you need to know about the flu:


On National Influenza Vaccination Week, the Centers for Disease Control and Prevention provides the following information about the flu.

Influenza Disease

1. Influenza (the flu) can be a serious disease that can lead to hospitalization and sometimes even death. Anyone can get sick from the flu.

2. While the flu can make anyone sick, certain people are at greater risk for serious complications from the flu, that can cause hospitalization or even death, including:

a) adults 65 years of age and older

b) children younger than 5, but especially younger than 2 years old

c) people with chronic lung disease (such as asthma and COPD), diabetes (type 1 and 2), heart disease, neurologic conditions, and certain other long-term medical conditions, even if these are well managed

d) those who are morbidly obese (BMI of 40 or greater)

e) pregnant women and women within the first two weeks after delivery (2 weeks post-partum)

f) other groups at increased risk of flu complications are listed at http://www.cdc.gov/flu/about/disease/high_risk.htm

3. Much of the U.S. population is at increased risk from serious flu complications, either because of their age or because they have a medical condition like asthma, diabetes (type 1 and 2), heart conditions, or because they are pregnant.

a) For example, more than 30 percent of people 50 through 64 years of age have one or more chronic medical conditions that put them at increased risk of serious complications from flu.

b) For example, all children younger than 5 years (and especially children younger than 2 years), and all adults 65 years and older, are at increased risk of serious flu-related complications.

4. Symptoms of influenza can include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Some people may also have vomiting and diarrhea.

5. People may be infected with the flu and have no symptoms at all or only respiratory symptoms without a fever.

6. Flu viruses are constantly changing. Each flu season, different flu viruses can spread, and they can affect people differently based on differences in the immune system. Even healthy children and adults can get very sick from the flu.

7. In the United States, thousands of healthy adults and children have to visit the doctor or be hospitalized from flu complications each year. Flu vaccination can help protect you and your family from the flu and its complications.

8. Flu seasons are unpredictable. The severity of influenza seasons can differ substantially from year to year. Over a period of 30 years, between 1976 and 2006, estimates of yearly flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people during the most severe season.

a) Each year in the United States on average: An estimated 5-20 percent of the population can be infected with the flu, and more than 200,000 people may be hospitalized during a flu season.

b) The 2009 H1N1 pandemic is an example of how unpredictable the flu can be. For more information about the 2009 H1N1 pandemic, see http://www.cdc.gov/h1n1flu/.

9. Since 2004-2005, flu-related deaths in children reported to CDC during regular influenza seasons have ranged from 35 deaths (during 2011-2012) to over 165 deaths (during 2012-2013). However, during the 2009 H1N1 influenza pandemic, (April 15, 2009 to October 2, 2010), 348 pediatric deaths were reported to CDC.

a. More information about pediatric deaths since the 2004-2005 flu season is available in the interactive pediatric death web application at http://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.

10. To date, most flu-related pediatric deaths have occurred in children who were not vaccinated against flu.

11. An average of over 200,000 people in the United States are hospitalized each year from flu and its related complications. Older adults, specifically those 65 years of age and older, typically account for about 60% of these flu-related hospitalizations each year and about 90% of flu-related deaths. (Thompson et al JAMA 2004, Dao et al JID 2010; 202(6):881–888)

12. The 2012-2013 season began early, was moderately severe and lasted longer than average compared with previous seasons (see “2012-2013 Flu Season Drawing to a Close” for more information). The 2012-13 season was a reminder of the unpredictability of influenza.

13. It is not possible to predict how mild or severe the 2013-2014 season will be.


1. The first and most important step in protecting against the flu is to get a flu vaccine each season.

2. Everyone 6 months of age and older is recommended to get the 2013-2014 flu vaccine, with rare exceptions.

3. You should get your flu vaccine soon after it becomes available, ideally by October. However, as long as flu viruses are circulating, vaccination should continue throughout the flu season, even in January or later.

4. It’s best to get vaccinated before the flu starts to spread in your community. It is not possible to know exactly when the flu season will start each year. While seasonal influenza outbreaks can happen as early as October, most of the time influenza activity peaks in January or later. Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated so they are protected before influenza begins spreading in their community.

5. CDC recommends an annual flu vaccine as the first and best way to protect against influenza. There are two reasons for getting a flu vaccine every year:

6. The first reason is that because flu viruses are constantly changing, flu vaccines may be updated from one season to the next to protect against the viruses research indicates will be most common during the upcoming flu season.

7. The second reason that annual vaccination is recommended is that a person’s immune protection from the vaccine declines over time. Annual vaccination is needed for optimal protection.

8. Flu vaccination prevented an estimated 13.6 million flu cases, 5.8 million medical visits and nearly 113,000 flu-related hospitalizations in the United States over a 6-year period (2005-2011), according to a study by CDC experts.