Please see the preliminary recommendations at the end of this article.

How Effective is the Seasonal Influenza Vaccine?
The effectiveness of the vaccine depends, in part, on the match between the viruses in the vaccine and influenza viruses that are circulating in the community. However, it’s important to remember that even when the viruses are not closely matched, the vaccine can still protect many people and prevent flu-related complications.

As of February 9, 2008, nearly all H1N1 viruses tested at CDC were well-matched to the H1N1 vaccine strain. However, most of the H3N2 and B virus strains were different from those contained in the vaccine. This suggests that protection against circulating H3N2 and B virus strains may not be optimal. As stated above, however, even when the viruses are not closely matched, the vaccine can protect many people and prevent flu-related complications. Therefore, the CDC continues to recommend influenza vaccination even during seasons when there is a less than ideal match. This is particularly important for people at high risk for serious flu complications and their close contacts.

The provisional recommendations for the prevention and control of influenzain the 2008 — 2009 flu season include the following:

• Annual vaccination of children aged 6 months — 59 months should continue.
• Annual vaccination for all children aged 6 months — 18 years.
• Annual vaccination for all children aged 6 months — 18 years should begin no later than during the 2009 - 2010 influenza season.
• If feasible, annual vaccination of all children aged 5 years — 18 years should begin in 2008 when the vaccine for the 2008 - 2009 influenza season becomes available.
• Persons at higher risk of influenza complications because of underlying medical conditions, children aged 6 months — 23 months, and persons aged >49 years should receive TIV. Either trivalent inactivated influenza vaccine (TIV) or live, attenuated influenza vaccine (LAIV) should be used when vaccinating persons aged 2 — 49 years who do not have medical conditions that put them at higher risk for influenza complications.
• Children aged 6 months — 8 years should receive 2 doses of influenza vaccine (doses separated by >4 weeks) if they have not been vaccinated
  previously at any time with at least one dose of either LAIV or TIV.
• Clinicians and immunization program staff should screen for possible reactive airways diseases when considering use of LAIV for children aged 2 — 4 years, and should avoid use of this vaccine in children with asthma or a recent wheezing episode. The ACIP has previously provided recommendations on screening for possible reactive airways diseases in children aged 2 — 4 years.
• Recommendations for annual vaccination of persons in other age or risk groups were not changed, and can be found in Prevention and Control of Influenza: Recommendations of the ACIP, 2007.
• The 2008 — 2009 trivalent vaccine virus strains are A/Brisbane/59/2007 (H1N1)-like, A/Brisbane/10/2007 (H3N2)-like, and B/Florida/4/2006-like antigens. All three strains are different from the 2007-2008 Northern Hemisphere influenza vaccine.
• The antiviral medications recommended for chemoprophylaxis or treatment of influenza (oseltamivir or zanamivir) have not changed for the 2008 - 2009 influenza season.

• Businesses and the Workplace
  http://www.cdc.gov/flu/workplace/

• Key Facts about Influenza and the Influenza Vaccine
  http://www.cdc.gov/flu/keyfacts.htm

• Preventing the Flu
  http://www.cdc.gov/flu/protect/preventing.htm

• FACT SHEET - Influenza Symptoms, Protection, and What to Do If You Get Sick
  http://www.cdc.gov/flu/symptoms.htm

• Influenza (the Flu) - Questions & Answers
  http://www.cdc.gov/flu/about/qa/

• Information for Specific Groups
  http://www.cdc.gov/flu/groups.htm

• Understanding Flu Terms
  http://www.pandemicflu.gov/

People at high risk for complications from the flu:

• People 65 years and older;
• People who live in nursing homes and other long-term care facilities that house those with long-term illnesses;
• Adults and children 6 months and older with chronic heart or lung conditions, including asthma;
• Adults and children 6 months and older who needed regular medical care or were in a hospital during the previous year because of a metabolic disease (like diabetes), chronic kidney disease, or weakened immune system (including immune system problems caused by medicines or by infection with human immunodeficiency virus [HIV/AIDS]);
• Children 6 months to 18 years of age who are on long-term aspirin therapy. (Children given aspirin while they have influenza are at risk of Reye syndrome.);
• Women who will be pregnant during the influenza season;
• All children 6 to 23 months of age;
• People with any condition that can compromise respiratory function or the handling of respiratory secretions (that is, a condition that makes it hard to breathe or swallow, such as brain injury or disease, spinal cord injuries, seizure disorders, or other nerve or muscle disorders.)

People 50 to 64 years of age: Nearly one-third of people 50 to 64 years of age in the United States have one or more medical conditions that place them at increased risk for serious flu complications.

People who can transmit flu to others at high risk for complications: Any person in close contact with someone in a high-risk group (see above) should get vaccinated. This includes all health-care workers, caregivers of children 6 to 23 months of age, and close contacts of people 65 years and older.

The Centers for Disease Control has identified people who should get vaccinated for pneumonia each year. They are:

• People 65 and older;
• People with chronic heart, lung, or liver disease;
• People with diabetes;
• People with suppressed immune systems;
• People who have had their spleen removed or have sickle cell anemia;
• People who have leakage of spinal fluid or a chronic kidney condition that causes loss of protein through urine;
• People with organ or bone marrow transplants;
• People with chronic kidney failure.