Influenza (Flu)

Flu Facts
The viruses that cause influenza change rapidly, making different strains coexist on the planet at any given time. Influenza vaccines are developed each year to protect people from the three strains expected to be most prevalent.

ALL THE VIRUSES IN THE VACCINE ARE KILLED, SO IT IS NOT POSSIBLE TO GET THE FLU FROM THE VACCINE. MOST PEOPLE HAVE NO SIDE EFFECTS FROM THE INFLUENZA VACCINE. SORENESS AT THE INJECTION SITE AND/OR MINOR ACHES AND LOW GRADE FEVER MAY BE PRESENT FOR SEVERAL DAYS.
Since the immunity provided by the vaccine wanes after several months, it is given at the beginning of the "flu season"--usually late October or early November in the U.S. People traveling to other countries should be aware that influenza occurs throughout the year in tropical countries and that the "flu season" for temperate countries in the Southern Hemisphere is April to September.

Flu Shot Facts
Each year, the vaccine is updated to include the most current strains of the virus. After getting a flu shot, a person's body will create antibodies to fight the virus if exposed to it. Antibodies against flu develop and provide protection within 1 or 2 weeks after vaccination.

Flu Shot Myth
A common myth about the flu shot is that it can actually cause the flu. But the flu vaccine in the United States is made from killed influenza viruses, which means that it's impossible to catch the flu by getting this vaccine.

Groups at High Risk for Flu
1. Persons > 50 years of age.
2. Residents of nursing homes and other chronic-care facilities housing persons of any age with chronic medical conditions.
3. Adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including asthma.
4. Adults and children who have required regular medical follow-up or hospitalization during the preceding year because of chronic metabolic diseases (including diabetes mellitus), renal dysfunction, anemias, or immunosuppression (including immunosuppression caused by medications).
5. Children and teenagers (aged 6 months-18 years) who are receiving long-term aspirin therapy and therefore might be at risk of developing Reye's Syndrome after influenza infection.
6. Women who will be in the second or third trimester of pregnancy during the influenza season.

People at High Risk to Transmit Flu
1. Physicians, nurses, and other personnel in both hospital and outpatient-care settings, including emergency response workers.
2. Employees of nursing homes and chronic-care facilities who have contact with patients or residents.
3. Employees of assisted living and other residences for persons in high-risk groups.
4. Persons who provide home care to persons in high-risk groups.
5. Household members (including children) of persons in high-risk groups.

People Who SHOULD NOT Have Flu Vaccinations
1. Influenza vaccine should not be administered to persons known to have anaphylactic hypersensitivity to eggs or to other vaccine components without first consulting a physician. Use of an antiviral agent (amantadine or rimantadine) is an option for prevention of influenza A in such persons.
2. Persons with acute febrile illnesses usually should not be vaccinated until their symptoms have abated. However, minor illnesses with or without fever do not contraindicate the use of influenza vaccine, particularly among children with mild upper respiratory tract infection or allergic rhinitis.

What Is Influenza?
Influenza vaccination protects people from contracting influenza, a viral illness affecting the respiratory tract. In the U.S., "flu" outbreaks typically occur between November and April. Symptoms of influenza include fever, chills, muscle aching, and cough. Although the illness usually only lasts 3 to 7 days, some people have more severe cases or complications that require hospitalization. Thousands of people in the U.S. die each year as the result of the flu or its complications.
Annual vaccination with influenza vaccine is considered the single most important measure to prevent or to lessen the severity of influenza infection and is strongly recommended for high-risk groups. High-risk individuals should be vaccinated every year. Most people achieve protection from influenza vaccine approximately 2 weeks after receiving the immunization.

Who Else Should Have a Flu Vaccination?
1. Persons infected with human immunodeficiency virus (HIV) should be vaccinated because influenza symptoms might be prolonged and the risk for complications increased for some HIV-infected persons.
2. Breastfeeding mothers - Flu vaccine does not affect the safety of mothers who are breastfeeding or their infants. Breastfeeding does not adversely affect immune response and is not a contraindication for vaccination.
3. Persons traveling to certain foreign countries (depends on season and destination) should consider vaccination.
4. In routine years, vaccine is recommended for any person who wishes to reduce his/her risk of acquiring influenza infection. However, due to this year's anticipated vaccine delay/shortage, vaccine should be prioritized for persons who are at high-risk and their contacts.